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Intuthuko esheshayo ye-nanotechnology kanye nokuhlanganiswa kwayo ekusetshenzisweni kwansuku zonke kungasongela imvelo. Ngenkathi izindlela eziluhlaza zokuqothulwa kwezinto eziphilayo zisungulwe kahle, ukubuyiselwa kwezinto ezingcolisayo ezingaphili kuyindaba enkulu ngenxa yokuzwela kwazo okuphansi ekuguqulweni kwezinto eziphilayo kanye nokuntuleka kokuqonda ukusebenzisana kwezinto ezibonakalayo nezinto eziphilayo. Lapha, sisebenzisa imodeli ye-2D MXenes engaphili esekelwe ku-Nb ehlanganiswe nendlela elula yokuhlaziya ipharamitha yesimo ukuze kulandelwe indlela yokulungiswa kwezinto eziphilayo zezinto eziphilayo ze-2D ceramic nanomaterials yi-green microalgae Raphidocelis subcapitata. Sithole ukuthi i-microalgae yonakalisa i-MXenes esekelwe ku-Nb ngenxa yokusebenzisana kwe-physico-chemical okuhlobene nomhlaba. Ekuqaleni, ama-nanoflakes e-MXene anezingqimba ezi-single kanye nama-multilayer ayenamathele ebusweni be-microalgae, okwanciphisa kancane ukukhula kwe-algae. Kodwa-ke, lapho esebenzisana isikhathi eside nobuso, i-microalgae yaxosha ama-nanoflakes e-MXene futhi yawahlukanisa abe yi-NbO kanye ne-Nb2O5. Ngenxa yokuthi lawa ma-oxide awawona ubuthi kumaseli e-microalgae, adla ama-nanoparticles e-Nb oxide ngendlela yokumunca evuselela i-microalgae ngemva kwamahora angu-72 okwelashwa ngamanzi. Imiphumela yezakhamzimba ezihambisana nokumunca ibonakala nasekukhuleni kwevolumu yamaseli, ukuma kwawo okubushelelezi kanye noshintsho lwesilinganiso sokukhula. Ngokusekelwe kulokhu okutholakele, siphetha ngokuthi ukuba khona kwe-MXenes e-Nb isikhathi esifushane neside ezindaweni zemvelo zamanzi ahlanzekile kungabangela imiphumela emincane kuphela emvelweni. Kuyaphawuleka ukuthi, sisebenzisa ama-nanomaterials amabili-ntathu njengezinhlelo zemodeli, sibonisa ukuthi kungenzeka ukulandelela ukuguqulwa kwesimo ngisho nasezintweni ezicolekile. Sekukonke, lolu cwaningo luphendula umbuzo obalulekile oyisisekelo mayelana nezinqubo ezihlobene nokusebenzisana komhlaba eziqhuba indlela yokulungisa izinto eziphilayo zama-nanomaterials e-2D futhi lunikeza isisekelo sezifundo ezengeziwe zesikhathi esifushane neside zomthelela emvelweni wama-nanomaterials angabonakali e-crystalline.
Izinto ezisetshenziswayo ezitholakala emvelweni ziye zadala isithakazelo esikhulu selokhu zatholakala, futhi ubuchwepheshe obuhlukahlukene be-nanotechnologies busanda kungena esigabeni sesimanje1. Ngeshwa, ukuhlanganiswa kwezinto ezisetshenziswayo ezisetshenziswa nsuku zonke kungaholela ekukhishweni ngengozi ngenxa yokulahlwa okungafanele, ukuphathwa ngokunganaki, noma ingqalasizinda yokuphepha enganele. Ngakho-ke, kunengqondo ukucabanga ukuthi izinto ezisetshenziswayo, okuhlanganisa nezinto ezisetshenziswayo ezinezinhlangothi ezimbili (2D), zingakhishwa endaweni yemvelo, ukuziphatha kanye nomsebenzi wezinto eziphilayo okungakaqondakali ngokugcwele. Ngakho-ke, akumangazi ukuthi ukukhathazeka ngobuthi bemvelo kugxile ekhonweni lezinto ezisetshenziswayo ezisetshenziswa emvelweni ezitholakala ...
Ama-Microalgae ayizinto eziphilayo zakudala ezitholakala ngokwemvelo ezindaweni zamanzi ahlanzekile kanye nezindawo zasolwandle ezikhiqiza imikhiqizo ehlukahlukene yamakhemikhali ngokusebenzisa i-photosynthesis7. Ngakho-ke, abalulekile ezindaweni zemvelo zasemanzini8,9,10,11,12 kodwa futhi ayizinkomba ezibucayi, ezingabizi futhi ezisetshenziswa kabanzi zokuthikamezeka kwemvelo13,14. Njengoba amangqamuzana ama-microalgae anda ngokushesha futhi ngokushesha esabela ekubeni khona kwamakhemikhali ahlukahlukene, athembisa ukuthuthukiswa kwezindlela ezinobungani nemvelo zokwelapha amanzi angcoliswe izinto eziphilayo15,16.
Amaseli e-algae angasusa ama-ion angaphili emanzini ngokusebenzisa i-biosorption kanye nokuqongelela17,18. Ezinye izinhlobo ze-algal ezifana ne-Chlorella, i-Anabaena invar, i-Westiellopsis prolica, i-Stigeoclonium tenue kanye ne-Synechococcus sp. Kutholakale ukuthi ithwala futhi yondla ngisho nama-ion ensimbi anobuthi njenge-Fe2+, Cu2+, Zn2+ kanye ne-Mn2+19. Ezinye izifundo zibonise ukuthi ama-ion e-Cu2+, Cd2+, Ni2+, Zn2+ noma i-Pb2+ anciphisa ukukhula kwe-Scenedesmus ngokushintsha isimo seseli kanye nokubhubhisa ama-chloroplast awo20,21.
Izindlela eziluhlaza zokubola kwezinto ezingcolisa izinto eziphilayo kanye nokususwa kwama-ion ensimbi esindayo zidonsele ukunaka kososayensi nonjiniyela emhlabeni jikelele. Lokhu kungenxa yokuthi lezi zinto ezingcolisa izinto zicutshungulwa kalula esigabeni soketshezi. Kodwa-ke, izinto ezingcolisa izinto ezingaphili zibonakala ngokuncibilika kwamanzi okuphansi kanye nokuthambekela okuphansi kokuguqulwa kwezinto eziphilayo okuhlukahlukene, okubangela ubunzima obukhulu ekulungisweni, futhi kuncane kakhulu okwenziwe kule ndawo22,23,24,25,26. Ngakho-ke, ukusesha izixazululo ezinobungani nemvelo zokulungisa izinto ezingaphili kuseyindawo eyinkimbinkimbi futhi engakahlolwa. Ngenxa yezinga eliphezulu lokungaqiniseki mayelana nemiphumela yokuguqulwa kwezinto ezingaphili zezinto ezingaphili zezinto ezingaphili zezinto ezingaphili zezinto ezingaphili zezinto ezingaphili zezinto ezingaphili zezinto ezingaphili zezinto ezingaphili zezinto ezingaphili zezinto ezingaphili zinto ezingaphili izinto ...
Kulesi sifundo, sisebenzise i-microalgae eluhlaza njenge-ejenti yokulungisa amanzi esebenzayo yezinto ze-ceramic ezingaphili, kuhlanganiswe nokuqapha inqubo yokuwohloka kwe-MXene endaweni ekhona njengommeleli wezinto ze-ceramic ezingaphili. Igama elithi “MXene” libonisa i-stoichiometry yezinto ze-Mn+1XnTx, lapho i-M iyinsimbi yokuguquka kwasekuqaleni, i-X iyi-carbon kanye/noma i-nitrogen, i-Tx iyisiphetho somphezulu (isb., -OH, -F, -Cl), kanye no-n = 1, 2, 3 noma 427.28. Kusukela ekutholakaleni kwe-MXenes nguNaguib et al. Ama-Sensorics, ukwelashwa komdlavuza kanye nokuhlunga kwe-membrane 27,29,30. Ngaphezu kwalokho, ama-MXene angabhekwa njengezinhlelo zemodeli ze-2D ngenxa yokuzinza kwawo okuhle kakhulu kwe-colloidal kanye nokusebenzisana okungenzeka kwezinto eziphilayo31,32,33,34,35,36.
Ngakho-ke, indlela ethuthukiswe kulesi sihloko kanye nemibono yethu yocwaningo iboniswe kuMfanekiso 1. Ngokusho kwalo mbono, ama-microalgae aphula ama-MXene asekelwe ku-Nb abe ngamakhemikhali angewona anobuthi ngenxa yokusebenzisana okuhlobene ne-physico-chemical, okuvumela ukubuyiselwa okwengeziwe kwe-algae. Ukuze kuhlolwe lo mbono, kwakhethwa amalungu amabili omndeni wama-carbide ensimbi asekelwe ku-niobium kanye/noma ama-nitride (MXenes), okungukuthi i-Nb2CTx kanye ne-Nb4C3TX.
Indlela yokucwaninga kanye nemibono esekelwe ebufakazini yokululama kwe-MXene yi-green microalgae Raphidocelis subcapitata. Sicela uqaphele ukuthi lokhu kumane kuyisibonakaliso esihleliwe semibono esekelwe ebufakazini. Indawo ezungezile ichibi ihlukile endaweni yezakhamzimba esetshenziswayo kanye nezimo (isb., umjikelezo wosuku kanye nemikhawulo kwezakhamzimba ezibalulekile ezitholakalayo). Kudalwe nge-BioRender.com.
Ngakho-ke, ngokusebenzisa i-MXene njengohlelo lwemodeli, sivule umnyango wokutadisha imiphumela ehlukahlukene yezinto eziphilayo engenakubonwa ngezinye izinto ezivamile ze-nanomaterials. Ikakhulukazi, sibonisa ukuthi kungenzeka ukuthi izinto eziphilayo ze-nanomaterials ezinezinhlangothi ezimbili, njenge-MXenes ezisekelwe ku-niobium, yi-microalgae Raphidocelis subcapitata. Ama-Microalgae ayakwazi ukonakalisa ama-Nb-MXenes abe ama-oxide angewona anobuthi i-NbO kanye ne-Nb2O5, nawo ahlinzeka ngezakhamzimba ngendlela yokuthathwa kwe-niobium. Sekukonke, lolu cwaningo luphendula umbuzo obalulekile obalulekile mayelana nezinqubo ezihlotshaniswa nokusebenzisana kwe-physicochemical ebusweni obulawula izindlela zokulungiswa kwezinto eziphilayo ze-nanomaterials ezinezinhlangothi ezimbili. Ngaphezu kwalokho, sakha indlela elula esekelwe kwipharamitha yesimo yokulandelela izinguquko ezicashile esimweni sezinto ezisetshenziswa ze-2D nanomaterials. Lokhu kuphefumulela ucwaningo olwengeziwe lwesikhathi esifushane nolwesikhathi eside ngemiphumela ehlukahlukene yemvelo yezinto ezisetshenziswa ze-crystalline nanomaterials ezingaphili. Ngakho-ke, ucwaningo lwethu lwandisa ukuqonda kokuxhumana phakathi kobuso bezinto nezinto ezisetshenziswa zebhayoloji. Siphinde sinikeze isisekelo socwaningo olwandisiwe lwesikhathi esifushane nolwesikhathi eside lwemiphumela yalo engaba khona ezindaweni zemvelo zamanzi ahlanzekile, okungaqinisekiswa kalula manje.
Ama-MXenes amelela isigaba sezinto ezithokozisayo ezinezakhiwo zomzimba nezamakhemikhali ezihlukile nezikhangayo ngakho-ke ukusetshenziswa okuningi okungenzeka. Lezi zakhiwo zincike kakhulu ku-stoichiometry yazo kanye ne-surface chemistry. Ngakho-ke, ocwaningweni lwethu, sihlole izinhlobo ezimbili zama-MXenes asekelwe ku-Nb-based hierarchical single-layer (SL), i-Nb2CTx kanye ne-Nb4C3TX, njengoba imiphumela ehlukene yezinto eziphilayo zalezi zinto ezincane ingabonakala. Ama-MXenes akhiqizwa ezintweni zawo zokuqala ngokuqopha okuphezulu okukhethiwe kwezingqimba ze-MAX-phase A ezincane kakhulu ze-atomically. Isigaba se-MAX siyi-ceramic ye-ternary eyakhiwe ngamabhulokhi "ahlanganisiwe" ama-carbide ensimbi yokuguquguquka kanye nezingqimba ezincane zezinto "A" ezifana ne-Al, Si, kanye ne-Sn ene-stoichiometry ye-MnAXn-1. Ukwakheka kwesigaba sokuqala se-MAX kwabonwa ngokuskena i-electron microscopy (SEM) futhi kwakuhambisana nezifundo zangaphambilini (Bheka Ulwazi Olungeziwe, SI, Umfanekiso S1). I-Multilayer (ML) Nb-MXene itholakale ngemuva kokususa ungqimba lwe-Al nge-48% HF (i-hydrofluoric acid). Ukwakheka kwe-ML-Nb2CTx kanye ne-ML-Nb4C3TX kuhlolwe ngokuskena i-electron microscopy (SEM) (Izibalo S1c kanye ne-S1d ngokulandelana) futhi kwabonakala ukwakheka kwe-MXene okujwayelekile okunezingqimba, okufana nama-nanoflakes amabili adlula kuma-slits afana ne-pore ende. Womabili ama-Nb-MXene afana kakhulu nezigaba ze-MXene ezazenziwe ngaphambilini yi-acid etching27,38. Ngemva kokuqinisekisa isakhiwo se-MXene, sayifaka ngezingqimba ngokuhlanganiswa kwe-tetrabutylammonium hydroxide (TBAOH) kulandelwe ukugeza kanye ne-sonication, ngemva kwalokho sathola ama-nanoflakes e-2D Nb-MXene anezingqimba ezimbili noma eziphansi (SL).
Sisebenzise i-high resolution transmission electron microscopy (HRTEM) kanye ne-X-ray diffraction (XRD) ukuhlola ukusebenza kahle kokuchoboza nokuqhekeka okuqhubekayo. Imiphumela ye-HRTEM ecutshungulwe kusetshenziswa i-Inverse Fast Fourier Transform (IFFT) kanye ne-Fast Fourier Transform (FFT) iboniswe ku-Fig. 2. Ama-nanoflakes e-Nb-MXene aqondiswe phezulu ukuze kuhlolwe isakhiwo sesendlalelo se-athomu futhi kulinganiswe amabanga aphakathi. Izithombe ze-HRTEM zama-nanoflakes e-MXene Nb2CTx kanye ne-Nb4C3TX zembule uhlobo lwawo olunezingqimba ezincane ze-athomu (bheka i-Fig. 2a1, a2), njengoba kubikwe ngaphambilini nguNaguib et al.27 kanye noJastrzębska et al.38. Kuma-monolayers amabili aseduze e-Nb2CTx kanye ne-Nb4C3Tx, sinqume amabanga aphakathi kwama-0.74 kanye no-1.54 nm, ngokulandelana (Izithombe 2b1,b2), okuvumelana nemiphumela yethu yangaphambilini38. Lokhu kwaqinisekiswa ngokwengeziwe yi-inverse fast Fourier transform (Umfanekiso 2c1, c2) kanye ne-fast Fourier transform (Umfanekiso 2d1, d2) ekhombisa ibanga phakathi kwe-Nb2CTx kanye ne-Nb4C3Tx monolayers. Isithombe sibonisa ukushintshana kwamabhande okukhanya namnyama ahambisana nama-athomu e-niobium kanye ne-carbon, okuqinisekisa uhlobo lwezingqimba zama-MXenes afundwayo. Kubalulekile ukuqaphela ukuthi ama-spectra e-energy dispersive X-ray spectroscopy (EDX) atholwe ku-Nb2CTx kanye ne-Nb4C3Tx (Izibalo S2a kanye ne-S2b) abonisanga nsalela yesigaba sokuqala se-MAX, njengoba kungekho peak ye-Al etholakele.
Ukuchazwa kwama-nanoflakes e-SL Nb2CTx kanye ne-Nb4C3Tx MXene, okuhlanganisa (a) isithombe se-electron microscopy (HRTEM) se-side-view 2D nanoflake kanye nokuhambisanayo, (b) imodi yokuqina, (c) ukuguqulwa kwe-Fourier okusheshayo okuphambene (IFFT), (d) ukuguqulwa kwe-Fourier okusheshayo (FFT), (e) amaphethini e-X-ray e-Nb-MXenes. Ku-SL 2D Nb2CTx, izinombolo zivezwa njengo-(a1, b1, c1, d1, e1). Ku-SL 2D Nb4C3Tx, izinombolo zivezwa njengo-(a2, b2, c2, d2, e1).
Izilinganiso ze-X-ray diffraction ze-SL Nb2CTx kanye ne-Nb4C3Tx MXenes ziboniswe ku-Figs. 2e1 kanye ne-e2, ngokulandelana. Ama-peaks (002) ku-4.31 kanye no-4.32 ahambelana ne-MXenes Nb2CTx kanye ne-Nb4C3TX38,39,40,41 ezichazwe ngaphambilini ngokulandelana. Imiphumela ye-XRD iphinde ikhombise ukuba khona kwezinye izakhiwo ze-ML ezisele kanye nezigaba ze-MAX, kodwa ikakhulukazi amaphethini e-XRD ahlotshaniswa ne-SL Nb4C3Tx (Isithombe 2e2). Ukuba khona kwezinhlayiya ezincane zesigaba se-MAX kungachaza i-MAX peak eqinile uma kuqhathaniswa nezendlalelo ze-Nb4C3Tx ezihlanganisiwe ngokungahleliwe.
Ucwaningo olwengeziwe lugxile kuma-microalgae aluhlaza angohlobo lwe-R. subcapitata. Sikhethe ama-microalgae ngoba angabakhiqizi ababalulekile ababandakanyeka kuma-food webs amakhulu42. Futhi angenye yezinkomba ezinhle kakhulu zobuthi ngenxa yekhono lokususa izinto ezinobuthi ezithwalwa ziye emazingeni aphezulu ochungechunge lokudla43. Ngaphezu kwalokho, ucwaningo ku-R. subcapitata lungakhanyisa ubuthi obungalindelekile be-SL Nb-MXenes kuma-microorganisms avamile ahlanzekile. Ukuze kuboniswe lokhu, abacwaningi bacabange ukuthi i-microbe ngayinye inokuzwela okuhlukile kuma-compounds anobuthi akhona emvelweni. Eziningi zezinto eziphilayo, ukugcwala okuphansi kwezinto akuthinti ukukhula kwazo, kuyilapho ukugcwala okungaphezu komkhawulo othile kungazivimbela noma kubangele nokufa. Ngakho-ke, ezifundweni zethu zokuxhumana kobuso phakathi kwama-microalgae nama-MXenes kanye nokululama okuhambisanayo, sinqume ukuhlola ukugcwala okungenangozi nobuthi be-Nb-MXenes. Ukuze senze lokhu, sihlole amazinga angu-0 (njengereferensi), angu-0.01, 0.1 kanye no-10 mg l-1 MXene kanye nama-microalgae atheleleke kakhulu anamazinga aphezulu kakhulu e-MXene (100 mg l-1 MXene), okungaba kubi kakhulu futhi kubulale. . kunoma iyiphi indawo yemvelo.
Imiphumela ye-SL Nb-MXenes kuma-microalgae iboniswe ku-Figure 3, evezwe njengephesenti lokukhushulwa kokukhula (+) noma ukuvinjelwa (-) okulinganiswe kumasampula angu-0 mg l-1. Ukuze kuqhathaniswe, isigaba se-Nb-MAX kanye ne-ML Nb-MXenes nazo zahlolwa futhi imiphumela iboniswe ku-SI (bheka i-Fig. S3). Imiphumela etholakele iqinisekisile ukuthi i-SL Nb-MXenes cishe ayinabo ubuthi ngokuphelele ebangeni lokugxila okuphansi kusukela ku-0.01 kuya ku-10 mg/l, njengoba kuboniswe ku-Fig. 3a,b. Endabeni ye-Nb2CTx, asibonanga ubuthi obungaphezu kuka-5% ebangeni elibekiwe.
Ukukhuthazwa (+) noma ukuvinjelwa (-) kokukhula kwe-microalgae lapho kukhona i-SL (a) i-Nb2CTx kanye (b) i-Nb4C3TX MXene. Kuhlaziywe amahora angu-24, 48 kanye nama-72 okuxhumana kwe-MXene-microalgae. Idatha ebalulekile (ukuhlolwa kwe-t, p < 0.05) imakwe nge-asterisk (*). Idatha ebalulekile (ukuhlolwa kwe-t, p < 0.05) imakwe nge-asterisk (*). Значимые данные (t-критерий, p < 0,05) отмечены звездочкой (*). Idatha ebalulekile (ukuhlolwa kwe-t, p < 0.05) imakwe nge-asterisk (*).重要数据（t 检验，p <0.05）用星号(*) 标记。重要数据（t 检验，p <0.05）用星号(*) 标记。 Важные данные (t-test, p < 0,05) отмечены звездочкой (*). Idatha ebalulekile (ukuhlolwa kwe-t, p < 0.05) imakwe nge-asterisk (*).Imicibisholo ebomvu ikhombisa ukuqedwa kokukhuthazwa okuvimbelayo.
Ngakolunye uhlangothi, amazinga aphansi e-Nb4C3TX avele abe nobuthi obukhulu kancane, kodwa hhayi ngaphezu kuka-7%. Njengoba bekulindelekile, sibonile ukuthi ama-MXenes ayenobuthi obuphezulu kanye nokuvinjelwa kokukhula kwe-microalgae ku-100mg L-1. Ngokuthakazelisayo, azikho izinto ezibonise ukuthambekela okufanayo kanye nokuncika kwesikhathi kwemiphumela enobuthi/enobuthi uma kuqhathaniswa namasampula e-MAX noma e-ML (bheka i-SI ukuthola imininingwane). Ngenkathi esigabeni se-MAX (bheka i-Fig. S3) ubuthi bufinyelele cishe ku-15-25% futhi banda ngokuhamba kwesikhathi, ukuthambekela okuphambene kwabonwa ku-SL Nb2CTx kanye ne-Nb4C3TX MXene. Ukuvinjelwa kokukhula kwe-microalgae kwehla ngokuhamba kwesikhathi. Kufinyelele cishe ku-17% ngemva kwamahora angu-24 futhi kwehle kwaba ngaphansi kuka-5% ngemva kwamahora angu-72 (I-Fig. 3a, b, ngokulandelana).
Okubaluleke kakhulu, ku-SL Nb4C3TX, ukuvinjelwa kokukhula kwe-microalgae kufinyelele cishe ku-27% ngemuva kwamahora angama-24, kodwa ngemva kwamahora angama-72 kwehle kwaba cishe yi-1%. Ngakho-ke, sibhale umphumela obonwe njengokuvimbela okuphambene kokukhuthazwa, futhi umphumela wawunamandla kakhulu ku-SL Nb4C3TX MXene. Ukukhuthazwa kokukhula kwe-microalgae kwaphawulwa ngaphambilini nge-Nb4C3TX (ukuxhumana ku-10 mg L-1 amahora angama-24) uma kuqhathaniswa ne-SL Nb2CTx MXene. Umphumela wokuguqula ukuvinjelwa nokukhuthaza uboniswe kahle ku-biomass doubling rate curve (bheka uMfanekiso S4 ukuthola imininingwane). Kuze kube manje, ubuthi be-eco-toxicity be-Ti3C2TX MXene kuphela obufundwe ngezindlela ezahlukene. Akuyona ubuthi kuma-zebrafish embryos44 kodwa bunobuthi obulinganiselayo eco-toxic ezitshalweni ze-microalgae Desmodesmus quadricauda kanye ne-Sorghum saccharatum45. Ezinye izibonelo zemiphumela ethile zifaka ubuthi obuphezulu emigqeni yamaseli omdlavuza kunemigqeni yamaseli evamile46,47. Kungacatshangwa ukuthi izimo zokuhlola zingathinta izinguquko ekukhuleni kwe-microalgae okubonwe lapho kukhona i-Nb-MXenes. Isibonelo, i-pH engaba ngu-8 ku-chloroplast stroma ilungele ukusebenza kahle kwe-enzyme ye-RuBisCO. Ngakho-ke, izinguquko ze-pH zithinta kabi izinga le-photosynthesis48,49. Kodwa-ke, asibonanga izinguquko ezibalulekile ku-pH ngesikhathi sokuhlola (bheka i-SI, Umfanekiso S5 ukuthola imininingwane). Ngokuvamile, amasiko e-microalgae ane-Nb-MXenes anciphise kancane i-pH yesisombululo ngokuhamba kwesikhathi. Kodwa-ke, lokhu kwehla kwakufana noshintsho ku-pH ye-medium emsulwa. Ngaphezu kwalokho, ububanzi bokuhlukahluka okutholiwe babufana nobo obulinganiswa nge-culture emsulwa ye-microalgae (isampula yokulawula). Ngakho-ke, siphetha ngokuthi i-photosynthesis ayithintwa izinguquko ku-pH ngokuhamba kwesikhathi.
Ngaphezu kwalokho, ama-MXene ahlanganisiwe aneziphetho zobuso (ezibizwa ngokuthi i-Tx). Lawa amaqembu asebenzayo ikakhulukazi -O, -F kanye no-OH. Kodwa-ke, i-surface chemistry ihlobene ngqo nendlela yokwenza izinto. La maqembu aziwa ngokusatshalaliswa ngokungahleliwe phezu kobuso, okwenza kube nzima ukubikezela umphumela wawo ezimpahleni ze-MXene50. Kungaphikiswana ngokuthi i-Tx ingaba amandla okukhulisa i-oxidation ye-niobium ngokukhanya. Amaqembu asebenzayo obuso ahlinzeka ngezindawo eziningi zokubambelela zama-photocatalysts awo angaphansi ukuze akhe ama-heterojunctions51. Kodwa-ke, ukwakheka kwe-growth medium akuzange kunikeze i-photocatalyst ephumelelayo (ukwakheka kwe-medium okuningiliziwe kungatholakala ku-SI Table S6). Ngaphezu kwalokho, noma yikuphi ukuguqulwa kobuso nakho kubaluleke kakhulu, njengoba umsebenzi webhayoloji we-MXenes ungashintshwa ngenxa yokucubungula ngemuva kwesendlalelo, i-oxidation, ukuguqulwa kobuso bamakhemikhali bamakhemikhali e-organic kanye ne-inorganic52,53,54,55,56 noma ubunjiniyela be-surface charge38. Ngakho-ke, ukuze sihlole ukuthi i-niobium oxide ihlobene yini nokungazinzi kwezinto ezibonakalayo endaweni, senze izifundo zamandla e-zeta (ζ) endaweni yokukhula kwe-microalgae kanye namanzi ahlanjululwe (ukuze siqhathanise). Imiphumela yethu ikhombisa ukuthi ama-SL Nb-MXenes azinzile kahle (bheka i-SI Fig. S6 ukuthola imiphumela ye-MAX kanye ne-ML). Amandla e-zeta e-SL MXenes angaba ngu--10 mV. Endabeni ye-SR Nb2CTx, inani le-ζ lincane kakhulu kunele-Nb4C3Tx. Ushintsho olunjalo enanini le-ζ lungabonisa ukuthi ubuso bama-nanoflakes e-MXene ashajwe kabi bumunca ama-ion ashajwe kahle endaweni yokukhula. Ukulinganiswa kwesikhashana kwamandla e-zeta kanye nokuqhuba kwe-Nb-MXenes endaweni yokukhula (bheka Izibalo S7 kanye ne-S8 ku-SI ukuthola imininingwane eyengeziwe) kubonakala sengathi kusekela umbono wethu.
Kodwa-ke, womabili ama-Nb-MXene SL abonise izinguquko ezincane kusukela ku-zero. Lokhu kubonisa ngokusobala ukuzinza kwawo endaweni yokukhula kwe-microalgae. Ngaphezu kwalokho, sihlole ukuthi ukuba khona kwe-microalgae yethu eluhlaza kuzothinta ukuzinza kwe-Nb-MXenes endaweni yokukhula. Imiphumela ye-zeta potential kanye ne-conductivity ye-MXenes ngemuva kokuxhumana ne-microalgae kwimidiya yezakhamzimba kanye namasiko ngokuhamba kwesikhathi ingatholakala ku-SI (Izibalo S9 kanye ne-S10). Ngokuthakazelisayo, siphawulile ukuthi ukuba khona kwe-microalgae kubonakala sengathi kuzinzisa ukusabalala kwe-MXenes zombili. Endabeni ye-Nb2CTx SL, i-zeta potential yehle kancane ngokuhamba kwesikhathi yaba amanani angemihle kakhulu (-15.8 uma kuqhathaniswa ne--19.1 mV ngemva kwamahora angu-72 okufukamela). I-zeta potential ye-SL Nb4C3TX yanda kancane, kodwa ngemva kwamahora angu-72 yayisabonisa ukuzinza okuphezulu kune-nanoflakes ngaphandle kokuba khona kwe-microalgae (-18.1 uma kuqhathaniswa ne--9.1 mV).
Sithole nokuthi izixazululo ze-Nb-MXene zinomoya ophansi lapho kukhona khona i-microalgae, okubonisa inani eliphansi lama-ion endaweni yezakhamzimba. Okuphawulekayo ukuthi ukungazinzi kwama-MXene emanzini kubangelwa kakhulu yi-oxidation engaphezulu57. Ngakho-ke, sisola ukuthi i-microalgae eluhlaza ngandlela thile yasusa ama-oxide akheke ebusweni be-Nb-MXene futhi yaze yavimbela nokuvela kwawo (i-oxidation ye-MXene). Lokhu kungabonakala ngokutadisha izinhlobo zezinto ezimuncwa yi-microalgae.
Nakuba izifundo zethu ze-ecotoxicological zibonise ukuthi ama-microalgae akwazile ukunqoba ubuthi be-Nb-MXenes ngokuhamba kwesikhathi kanye nokuvinjelwa okungavamile kokukhula okukhuthaziwe, inhloso yocwaningo lwethu kwakuwukuphenya izindlela zokusebenza ezingaba khona. Lapho izinto eziphilayo ezifana ne-algae zivezwa kuma-compounds noma izinto ezingajwayelekile ezindaweni zazo zemvelo, zingasabela ngezindlela ezahlukene58,59. Uma kungekho ama-oxide ensimbi anobuthi, ama-microalgae angondla wona, okuwavumela ukuba akhule njalo60. Ngemva kokungenisa izinto ezinobuthi, izindlela zokuzivikela zingase zisebenze, njengokushintsha isimo noma isimo. Amathuba okumuncwa nawo kumele acatshangelwe58,59. Okuphawulekayo ukuthi noma yiluphi uphawu lwendlela yokuzivikela luyisibonakaliso esicacile sobuthi be-compound yokuhlola. Ngakho-ke, emsebenzini wethu owengeziwe, siphenye ukusebenzisana okungenzeka kobuso phakathi kwama-nanoflakes e-SL Nb-MXene kanye nama-microalgae yi-SEM kanye nokumuncwa okungenzeka kwe-MXene esekelwe ku-Nb yi-X-ray fluorescence spectroscopy (XRF). Qaphela ukuthi ukuhlaziywa kwe-SEM kanye ne-XRF kwenziwa kuphela ekugxilweni okuphezulu kwe-MXene ukubhekana nezinkinga zobuthi bomsebenzi.
Imiphumela ye-SEM iboniswe ku-Fig.4. Amaseli e-microalgae angalashwanga (bheka i-Fig. 4a, isampula yokubhekisela) abonise ngokusobala isimo se-R. subcapitata esijwayelekile kanye nesimo seseli esifana ne-croissant. Amaseli abonakala eyisicaba futhi engahlelekile kahle. Amanye amaseli e-microalgae ahlangana futhi abambene, kodwa lokhu kungenzeka ukuthi kwabangelwa inqubo yokulungiselela isampula. Ngokuvamile, amaseli e-microalgae amsulwa ayenobuso obubushelelezi futhi awazange abonise noma yiziphi izinguquko zesimo.
Izithombe ze-SEM ezibonisa ukusebenzisana kobuso phakathi kwe-microalgae eluhlaza kanye nama-nanosheet e-MXene ngemva kwamahora angu-72 okuxhumana ekugxilweni okukhulu (100 mg L-1). (a) I-microalgae eluhlaza engalashwanga ngemva kokuxhumana ne-SL (b) Nb2CTx kanye (c) Nb4C3TX MXenes. Qaphela ukuthi ama-nanoflakes e-Nb-MXene amakwe ngemicibisholo ebomvu. Ukuze kuqhathaniswe, izithombe ezivela kuma-microscope optical nazo zengeziwe.
Ngokuphambene nalokho, amaseli e-microalgae afakwe ama-nanoflakes e-SL Nb-MXene onakele (bheka uMfanekiso 4b, c, imicibisholo ebomvu). Endabeni ye-Nb2CTx MXene (Umfanekiso 4b), ama-microalgae avame ukukhula ngama-nanoscales anamathiselwe anezinhlangothi ezimbili, angashintsha ukuma kwawo. Okuphawulekayo ukuthi siphinde sabona lezi zinguquko ngaphansi kwe-microscopy ekhanyayo (bheka uMfanekiso we-SI S11 ukuthola imininingwane). Lokhu kuguquka kokwakheka kunesisekelo esinengqondo ku-physiology ye-microalgae kanye nekhono lawo lokuzivikela ngokushintsha ukuma kweseli, njengokwandisa ivolumu yeseli61. Ngakho-ke, kubalulekile ukuhlola inani lamaseli e-microalgae axhumana ne-Nb-MXenes. Izifundo ze-SEM zibonise ukuthi cishe amaseli e-microalgae angu-52% atholakale kuma-Nb-MXenes, kuyilapho amaseli angu-48% ala maseli e-microalgae egwema ukuthintana. Ku-SL Nb4C3Tx MXene, ama-microalgae azama ukugwema ukuthintana ne-MXene, ngaleyo ndlela athole indawo futhi akhule kusuka kuma-nanoscales anezinhlangothi ezimbili (Isithombe 4c). Kodwa-ke, asibonanga ukungena kwama-nanoscales kumaseli e-microalgae kanye nomonakalo wawo.
Ukuzigcina nakho kuyindlela yokusabela encike esikhathini ekuvinjweni kwe-photosynthesis ngenxa yokumuncwa kwezinhlayiya ebusweni beseli kanye nalokho okubizwa ngokuthi umphumela womthunzi (umthunzi)62. Kusobala ukuthi into ngayinye (isibonelo, ama-nanoflakes e-Nb-MXene) aphakathi kwe-microalgae nomthombo wokukhanya anciphisa inani lokukhanya okumuncwa yi-chloroplast. Kodwa-ke, asinakungabaza ukuthi lokhu kunomthelela omkhulu emiphumeleni etholakele. Njengoba kuboniswe ngokubuka kwethu okubonakalayo, ama-nanoflakes e-2D awazange asongwe ngokuphelele noma anamathele ebusweni be-microalgae, ngisho nalapho ama-microalgae cells exhumana ne-Nb-MXenes. Esikhundleni salokho, ama-nanoflakes avele aqondiswe kuma-microalgae cells ngaphandle kokumboza ubuso bawo. Isethi enjalo yama-nanoflakes/microalgae ayikwazi ukunciphisa kakhulu inani lokukhanya okumuncwa ngama-microalgae cells. Ngaphezu kwalokho, ezinye izifundo zibonise ngisho nokuthuthuka ekumuncweni kokukhanya yizinto eziphilayo ze-photosynthetic lapho kukhona izinto ezincane ze-nanomaterials63,64,65,66.
Njengoba izithombe ze-SEM zingazange ziqinisekise ngokuqondile ukumuncwa kwe-niobium ngamaseli e-microalgae, ucwaningo lwethu olwengeziwe luphendukele ekuhlaziyweni kwe-X-ray fluorescence (XRF) kanye ne-X-ray photoelectron spectroscopy (XPS) ukuze kucaciswe le nkinga. Ngakho-ke, siqhathanise ubukhali beziqongo ze-Nb zamasampula e-microalgae abhekisele kuwo angazange asebenzisane nama-MXenes, ama-MXene nanoflakes ahlukaniswe ebusweni bamaseli e-microalgae, kanye namaseli e-microalgal ngemva kokususwa kwama-MXenes anamathiselwe. Kubalulekile ukuqaphela ukuthi uma kungekho ukumuncwa kwe-Nb, inani le-Nb elitholwe ngamaseli e-microalgae kufanele libe yi-zero ngemva kokususwa kwama-nanoscales anamathiselwe. Ngakho-ke, uma ukumuncwa kwe-Nb kwenzeka, imiphumela ye-XRF kanye ne-XPS kufanele ibonise i-Nb peak ecacile.
Endabeni yama-spectra e-XRF, amasampula e-microalgae abonise ama-Nb peaks e-SL Nb2CTx kanye ne-Nb4C3Tx MXene ngemuva kokuxhumana ne-SL Nb2CTx kanye ne-Nb4C3Tx MXene (bheka uMfanekiso 5a, futhi qaphela ukuthi imiphumela ye-MAX kanye ne-ML MXenes iboniswe ku-SI, Ama-Fig S12–C17). Ngokuthakazelisayo, ukuqina kwe-Nb peak kuyafana kuzo zombili izimo (ama-red bars ku-Fig. 5a). Lokhu kubonise ukuthi i-algae ayikwazanga ukumunca i-Nb eningi, futhi umthamo omkhulu wokuqongelela i-Nb watholakala kumaseli, yize i-Nb4C3Tx MXene ephindwe kabili yayinamathele kumaseli e-microalgae (ama-blue bars ku-Fig. 5a). Okuphawulekayo ukuthi ikhono le-microalgae lokumunca izinsimbi lincike ekugxilweni kwama-oxide ensimbi endaweni ezungezile67,68. USamshada et al.67 bathole ukuthi amandla okumunca e-algae yamanzi ahlanzekile ayancipha ngokwanda kwe-pH. URaize nabanye.68 baphawule ukuthi ikhono lokhula lwasolwandle lokumunca izinsimbi laliphakeme cishe ngo-25% ku-Pb2+ kune-Ni2+.
(a) Imiphumela ye-XRF yokumuncwa kwe-basal Nb ngamaseli e-microalgae aluhlaza afakwe ekugxilweni okukhulu kwe-SL Nb-MXenes (100 mg L-1) amahora angama-72. Imiphumela ikhombisa ukuba khona kwe-α kumaseli e-microalgae ahlanzekile (isampula yokulawula, amakholomu ampunga), ama-nanoflakes e-2D ahlukaniswe namaseli e-microalgae angaphezulu (amakholomu aluhlaza okwesibhakabhaka), namaseli e-microalgae ngemva kokuhlukaniswa kwama-nanoflakes e-2D ebusweni (amakholomu abomvu). Inani le-elemental Nb, (b) iphesenti lokwakheka kwamakhemikhali kwezingxenye eziphilayo ze-microalgae (C=O kanye ne-CHx/C–O) kanye nama-oxide e-Nb akhona kumaseli e-microalgae ngemva kokufakwa ku-SL Nb-MXenes, (c–e) Ukufakwa kwe-compositional peak ye-XPS SL Nb2CTx spectra kanye (fh) ne-SL Nb4C3Tx MXene efakwe ngaphakathi ngamaseli e-microalgae.
Ngakho-ke, besilindele ukuthi i-Nb ingamuncwa amaseli e-algal ngesimo sama-oxide. Ukuze sihlole lokhu, senze izifundo ze-XPS kumaseli e-MXenes Nb2CTx kanye ne-Nb4C3TX kanye ne-algae. Imiphumela yokusebenzisana kwe-microalgae ne-Nb-MXenes kanye ne-MXenes ezihlukaniswe kumaseli e-algae iboniswe ku-Figs. 5b. Njengoba bekulindelekile, sithole iziqongo ze-Nb 3d kumasampula e-microalgae ngemuva kokususwa kwe-MXene ebusweni be-microalgae. Ukunqunywa kobuningi kwama-C=O, CHx/CO, kanye nama-Nb oxides kubalwe ngokusekelwe kuma-spectra e-Nb 3d, O 1s, kanye ne-C 1s atholwe nge-Nb2CTx SL (Isithombe 5c–e) kanye ne-Nb4C3Tx SL (Isithombe 5c–e). ) atholwe kuma-microalgae afakwe incubation. Isibalo 5f–h) MXenes. Ithebula S1-3 libonisa imininingwane yamapharamitha aphezulu kanye nekhemistri iyonke ephuma ekulinganeni. Kuyaphawuleka ukuthi izifunda ze-Nb 3d ze-Nb2CTx SL kanye ne-Nb4C3Tx SL (Isithombe 5c, f) zihambisana nengxenye eyodwa ye-Nb2O5. Lapha, asitholanga zintaba ezihlobene ne-MXene kuma-spectra, okubonisa ukuthi amaseli e-microalgae amunca kuphela uhlobo lwe-oxide lwe-Nb. Ngaphezu kwalokho, silinganise i-C1 s spectrum ngezingxenye ze-C–C, CHx/C–O, C=O, kanye ne-COOH. Sabela izintaba ze-CHx/C–O kanye ne-C=O emnikelweni wezinto eziphilayo wamaseli e-microalgae. Lezi zingxenye eziphilayo zibala u-36% kanye no-41% weziqongo ze-C1s ku-Nb2CTx SL kanye ne-Nb4C3TX SL, ngokulandelana. Sabe sesifaka i-O 1s spectra ye-SL Nb2CTx kanye ne-SL Nb4C3TX nge-Nb2O5, izingxenye eziphilayo ze-microalgae (CHx/CO), kanye namanzi afakwe emanzini.
Ekugcineni, imiphumela ye-XPS ibonise ngokucacile isimo se-Nb, hhayi nje ukuba khona kwayo. Ngokwesikhundla sesignali ye-Nb 3d kanye nemiphumela yokuhlukana, siyaqinisekisa ukuthi i-Nb imuncwa kuphela ngesimo sama-oxide hhayi ama-ion noma i-MXene uqobo. Ngaphezu kwalokho, imiphumela ye-XPS ibonise ukuthi amaseli e-microalgae anekhono elikhulu lokumunca ama-Nb oxides avela ku-SL Nb2CTx uma kuqhathaniswa ne-SL Nb4C3TX MXene.
Nakuba imiphumela yethu yokuthathwa kwe-Nb ihlaba umxhwele futhi isivumela ukuthi sibone ukuwohloka kwe-MXene, ayikho indlela etholakalayo yokulandelela izinguquko zesimo ezihambisanayo kuma-nanoflakes e-2D. Ngakho-ke, sinqume futhi ukuthuthukisa indlela efanelekile engaphendula ngqo kunoma yiziphi izinguquko ezenzeka kuma-nanoflakes e-2D Nb-MXene namaseli e-microalgae. Kubalulekile ukuqaphela ukuthi sicabanga ukuthi uma izinhlobo ezisebenzisanayo zidlula kunoma yikuphi ukuguqulwa, ukubola noma ukuqhekeka, lokhu kufanele kubonakale ngokushesha njengezinguquko kumapharamitha womumo, njengobubanzi bendawo eyindilinga efanayo, ukuzungeza, ububanzi be-Feret, noma ubude be-Feret. Njengoba la mapharamitha afanele ukuchaza izinhlayiya ezinde noma ama-nanoflakes anobukhulu obubili, ukulandelela kwawo ngokuhlaziywa kwesimo sezinhlayiya ezinamandla kuzosinika ulwazi olubalulekile mayelana nokuguqulwa kwesimo sama-nanoflakes e-SL Nb-MXene ngesikhathi sokunciphisa.
Imiphumela etholakele iboniswe kuMfanekiso 6. Ukuze siqhathanise, siphinde sahlola isigaba sokuqala se-MAX kanye ne-ML-MXenes (bheka i-SI Figures S18 kanye ne-S19). Ukuhlaziywa okunamandla komumo wezinhlayiyana kubonise ukuthi wonke amapharamitha womumo wama-Nb-MXene SL amabili ashintshe kakhulu ngemva kokuxhumana nama-microalgae. Njengoba kuboniswe yipharamitha efanayo yobubanzi bendawo eyindilinga (Umfanekiso 6a, b), ukuqina okuphezulu kwengxenye yama-nanoflakes amakhulu kubonisa ukuthi avame ukubola abe yizingcezu ezincane. Kumfanekiso 6c, u-d ukhombisa ukwehla kweziqongo ezihlotshaniswa nosayizi ophambene wama-flakes (ukunwebeka kwama-nanoflakes), okubonisa ukuguqulwa kwama-nanoflakes e-2D abe yisimo esifana nezinhlayiyana. Umfanekiso 6e-h ukhombisa ububanzi nobude be-Feret, ngokulandelana. Ububanzi nobude be-Feret kuyimingcele ehambisanayo futhi ngakho-ke kufanele kucatshangelwe ndawonye. Ngemva kokufakwa kwama-nanoflakes e-2D Nb-MXene lapho kukhona ama-microalgae, iziqongo zawo zokuhlobana kwe-Feret zashintsha futhi ukuqina kwazo kwehla. Ngokusekelwe kule miphumela ehlanganiswe ne-morphology, i-XRF kanye ne-XPS, siphethe ngokuthi izinguquko ezibonwe zihlobene kakhulu ne-oxidation njengoba ama-MXene axubile eba nemibimbi kakhulu futhi ehlukana abe yizicucu kanye nezinhlayiya ze-oxide eziyindilinga69,70.
Ukuhlaziywa kokuguqulwa kwe-MXene ngemva kokuxhumana ne-microalgae eluhlaza. Ukuhlaziywa kwesimo sezinhlayiya ezinamandla kubheka amapharamitha anjengo-(a, b) ububanzi bendawo elinganayo eyindilinga, (c, d) ukuzungeza, (e, f) ububanzi be-Feret kanye no-(g, h) ubude be-Feret. Ngenxa yalokhu, amasampula amabili e-microalgae abhekiselwe kuwo ahlaziywe kanye ne-SL Nb2CTx eyinhloko kanye ne-SL Nb4C3Tx MXenes, i-SL Nb2CTx kanye ne-SL Nb4C3Tx MXenes, i-microalgae eyonakele, kanye ne-microalgae elashwe i-SL Nb2CTx kanye ne-SL Nb4C3Tx MXenes. Imicibisholo ebomvu ikhombisa ukuguquka kwamapharamitha esimo sama-nanoflakes amabili afundwe.
Njengoba ukuhlaziywa kwepharamitha yesimo kuthembekile kakhulu, kungaveza nezinguquko zesimo kumaseli e-microalgae. Ngakho-ke, sihlaziye ububanzi bendawo eyindilinga, ukujikeleza, kanye nobubanzi/ubude be-Feret bamaseli e-microalgae ahlanzekile namaseli ngemva kokuxhumana nama-nanoflakes e-2D Nb. Ku-Fig. 6a–h kukhombisa izinguquko kumapharamitha wesimo samaseli e-algae, njengoba kuboniswa ukwehla kokuqina okuphezulu kanye nokushintsha kwe-maxima kuya emananini aphezulu. Ikakhulukazi, amapharamitha we-cell roundness abonise ukwehla kwamaseli amade kanye nokwanda kwamaseli ayindilinga (Fig. 6a, b). Ngaphezu kwalokho, ububanzi bamaseli e-Feret bukhuphuke ngama-micrometer amaningana ngemva kokuxhumana ne-SL Nb2CTx MXene (Fig. 6e) uma kuqhathaniswa ne-SL Nb4C3TX MXene (Fig. 6f). Sisola ukuthi lokhu kungenzeka ngenxa yokumuncwa okunamandla kwama-Nb oxides yi-microalgae lapho esebenzisana ne-Nb2CTx SR. Ukunamathela okungaqinile kwama-Nb flakes ebusweni bawo kungabangela ukukhula kwamaseli ngomphumela omncane womthunzi.
Ukubheka kwethu izinguquko kumapharamitha okwakheka nobukhulu be-microalgae kuhambisana nezinye izifundo. I-green algae ingashintsha isimo sayo ngokuphendula ekucindezelekeni kwemvelo ngokushintsha usayizi weseli, isimo noma i-metabolism61. Isibonelo, ukushintsha usayizi wamaseli kwenza kube lula ukumuncwa kwezakhamzimba71. Amaseli amancane e-algae abonisa ukumuncwa okuphansi kwezakhamzimba kanye nesivinini sokukhula esiphazamisekile. Ngokuphambene nalokho, amaseli amakhulu avame ukudla izakhamzimba eziningi, ezibe sezifakwa ngaphakathi kweseli72,73. UMachado noSoares bathole ukuthi i-fungicide triclosan ingandisa usayizi weseli. Bathole nezinguquko ezijulile esimweni se-algae74. Ngaphezu kwalokho, uYin et al.9 nabo baveze izinguquko zesimo se-algae ngemva kokuchayeka kuma-nanocomposites ancishisiwe e-graphene oxide. Ngakho-ke, kusobala ukuthi amapharamitha osayizi/esimo ashintshiwe e-microalgae abangelwa ukuba khona kwe-MXene. Njengoba lolu shintsho ngobukhulu nesimo lukhombisa izinguquko ekumuncweni kwezakhamzimba, sikholelwa ukuthi ukuhlaziywa kwamapharamitha osayizi nesimo ngokuhamba kwesikhathi kungabonisa ukumuncwa kwe-niobium oxide yi-microalgae lapho kukhona i-Nb-MXenes.
Ngaphezu kwalokho, ama-MXene angangcoliswa uma kukhona ulwelwe. UDalai nabanye.75 baqaphele ukuthi isimo se-algae eluhlaza esivezwe ku-nano-TiO2 kanye ne-Al2O376 sasingafani. Nakuba okubonwe yithi kufana nocwaningo lwamanje, kubalulekile kuphela ekutadisheni imiphumela yokulungiswa kwezinto eziphilayo maqondana nemikhiqizo yokuwohloka kwe-MXene lapho kukhona ama-nanoflakes e-2D hhayi ama-nanoparticles. Njengoba ama-MXene engonakala abe ama-metal oxides,31,32,77,78 kunengqondo ukucabanga ukuthi ama-nanoflakes ethu e-Nb angakha nama-Nb oxides ngemva kokuxhumana namaseli e-microalgae.
Ukuze sichaze ukwehla kwama-nanoflakes e-2D-Nb ngokusebenzisa indlela yokubola esekelwe enkambisweni yokubola, senze izifundo sisebenzisa i-high-resolution transmission electron microscopy (HRTEM) (Isithombe 7a,b) kanye ne-X-ray photoelectron spectroscopy (XPS) (Isithombe 7). 7c-i kanye namathebula S4-5). Zombili izindlela zifanelekile ukutadisha ukubola kwezinto ze-2D futhi ziyahambisana. I-HRTEM iyakwazi ukuhlaziya ukuwohloka kwezakhiwo ezinezingqimba ezimbili kanye nokuvela okulandelayo kwama-nanoparticles e-metal oxide, kuyilapho i-XPS ibucayi ezibophweni zangaphezulu. Ngale njongo, sihlole ama-nanoflakes e-2D Nb-MXene akhishwe kuma-microalgae cell dispersions, okungukuthi, ukuma kwawo ngemva kokuxhumana nama-microalgae cells (bheka Isithombe 7).
Izithombe ze-HRTEM ezibonisa isimo se-oxidized (a) SL Nb2CTx kanye (b) SL Nb4C3Tx MXenes, imiphumela yokuhlaziywa kwe-XPS ekhombisa (c) ukwakheka kwemikhiqizo ye-oxide ngemva kokunciphisa, (d–f) ukufaniswa kwezinga eliphezulu kwezingxenye ze-XPS spectra ye-SL Nb2CTx kanye ne-(g– i) Nb4C3Tx SL elungisiwe nge-microalgae eluhlaza.
Izifundo ze-HRTEM ziqinisekisile ukubola kwezinhlobo ezimbili zama-nanoflakes e-Nb-MXene. Nakuba ama-nanoflakes agcina isimo sawo esinezinhlangothi ezimbili ngezinga elithile, ukubola kwaholela ekubonakaleni kwama-nanoparticle amaningi amboze ubuso bama-nanoflakes e-MXene (bheka uMfanekiso 7a,b). Ukuhlaziywa kwe-XPS kwezibonakaliso ze-c Nb 3d kanye ne-O 1s kubonise ukuthi ama-Nb oxide akheke kuzo zombili izimo. Njengoba kuboniswe kuMfanekiso 7c, i-2D MXene Nb2CTx kanye ne-Nb4C3TX zinezibonakaliso ze-Nb 3d ezibonisa ukuba khona kwama-NbO kanye nama-Nb2O5 oxide, kuyilapho izimpawu ze-O 1s zibonisa inani lama-bond e-O–Nb ahlobene nokusebenza kobuso be-nanoflake ye-2D. Siphawulile ukuthi umnikelo we-Nb oxide unamandla uma uqhathaniswa ne-Nb-C kanye ne-Nb3+-O.
Ku-Fig. Izibalo 7g–i zibonisa ama-XPS spectra e-Nb 3d, C 1s, kanye ne-O 1s SL Nb2CTx (bheka Ama-Fig. 7d–f) kanye ne-SL Nb4C3TX MXene ahlukaniswe kumaseli e-microalgae. Imininingwane yamapharamitha aphezulu e-Nb-MXenes inikezwe kumaThebula S4–5, ngokulandelana. Siqale sahlaziya ukwakheka kwe-Nb 3d. Ngokungafani ne-Nb emuncwa amaseli e-microalgae, ku-MXene ehlukaniswe kumaseli e-microalgae, ngaphandle kwe-Nb2O5, kutholakale ezinye izingxenye. Ku-Nb2CTx SL, sibone umnikelo we-Nb3+-O ngenani elingu-15%, kuyilapho lonke i-spectrum ye-Nb 3d yayibuswa yi-Nb2O5 (85%). Ngaphezu kwalokho, isampula ye-SL Nb4C3TX iqukethe izingxenye ze-Nb-C (9%) kanye ne-Nb2O5 (91%). Lapha i-Nb-C ivela ezingqimbeni ezimbili zangaphakathi ze-athomu ze-carbide yensimbi ku-Nb4C3Tx SR. Sibe sesihlela ama-spectra e-C1s ezingxenyeni ezine ezahlukene, njengoba senzile kumasampula angaphakathi. Njengoba bekulindelekile, i-spectrum ye-C1s ibuswa yi-graphitic carbon, ilandelwe yiminikelo evela ezinhlayiyeni eziphilayo (CHx/CO kanye ne-C=O) ezivela kumaseli e-microalgae. Ngaphezu kwalokho, ku-spectrum ye-O1s, sibone umnikelo wezinhlobo eziphilayo zamaseli e-microalgae, i-niobium oxide, kanye namanzi afakwe emanzini.
Ngaphezu kwalokho, siphenye ukuthi ukuqhekeka kwe-Nb-MXenes kuhlotshaniswa yini nokuba khona kwezinhlobo ze-oxygen ezisabelayo (i-ROS) endaweni yezakhamzimba kanye/noma amaseli e-microalgae. Ngenxa yalokhu, sihlole amazinga e-singlet oxygen (1O2) endaweni yezakhamzimba kanye ne-glutathione yangaphakathi kweseli, i-thiol esebenza njenge-antioxidant kuma-microalgae. Imiphumela iboniswe ku-SI (Izibalo S20 kanye ne-S21). Ama-culture ane-SL Nb2CTx kanye ne-Nb4C3TX MXenes abonakala ngenani elincishisiwe le-1O2 (bheka Umfanekiso S20). Endabeni ye-SL Nb2CTx, i-MXene 1O2 yehliswe yaba cishe ngu-83%. Kwama-microalgae cultures asebenzisa i-SL, i-Nb4C3TX 1O2 yehle kakhulu, yaba ngu-73%. Ngokuthakazelisayo, izinguquko ku-1O2 zibonise ukuthambekela okufanayo nomphumela wokuvimbela obonwe ngaphambilini (bheka Umfanekiso 3). Kungaphikiswana ngokuthi ukufukamela ekukhanyeni okukhanyayo kungashintsha i-photooxidation. Kodwa-ke, imiphumela yokuhlaziywa kokulawula ibonise amazinga acishe abe njalo angu-1O2 ngesikhathi sokuhlolwa (Umfanekiso S22). Endabeni yamazinga e-ROS angaphakathi kweseli, sibone nomkhuba ofanayo wokwehla (bheka Umfanekiso S21). Ekuqaleni, amazinga e-ROS kumaseli e-microalgae akhuliswe lapho kukhona i-Nb2CTx kanye ne-Nb4C3Tx SLs adlula amazinga atholakala kumasiko ahlanzekile e-microalgae. Nokho, ekugcineni, kwabonakala sengathi i-microalgae yazivumelanisa nokuba khona kwe-Nb-MXenes zombili, njengoba amazinga e-ROS ehla afinyelela ku-85% kanye no-91% wamazinga alinganiswa kumasiko ahlanzekile e-microalgae afakwe i-SL Nb2CTx kanye ne-Nb4C3TX, ngokulandelana. Lokhu kungabonisa ukuthi i-microalgae izizwa ikhululekile ngokuhamba kwesikhathi lapho ikhona i-Nb-MXene kunasendaweni yezakhamzimba kuphela.
Ama-Microalgae ayiqembu elihlukahlukene lezinto eziphilayo ezisebenzisa i-photosynthesis. Ngesikhathi se-photosynthesis, aguqula i-carbon dioxide esemoyeni (i-CO2) ibe yi-organic carbon. Imikhiqizo ye-photosynthesis yi-glucose kanye ne-oxygen79. Sisola ukuthi i-oxygen eyakhiwe ngaleyo ndlela idlala indima ebalulekile ekufakweni kwe-Nb-MXenes. Enye incazelo engaba khona yalokhu ukuthi ipharamitha yokwehlukanisa umoya yakhiwa ngokucindezela okuphansi nokuphezulu kwe-oxygen ngaphandle nangaphakathi kwama-nanoflakes e-Nb-MXene. Lokhu kusho ukuthi noma kuphi lapho kunezindawo zokucindezela okuhlukile kwe-oxygen, indawo enezinga eliphansi izokwakha i-anode 80, 81, 82. Lapha, ama-microalgae anegalelo ekudalweni kwamaseli asebenzisa umoya ngokuhlukile ebusweni bama-MXene flakes, akhiqiza umoya-mpilo ngenxa yezakhiwo zawo ze-photosynthesis. Ngenxa yalokho, kwakheka imikhiqizo ye-biocorrosion (kulokhu, ama-niobium oxides). Esinye isici ukuthi ama-microalgae angakhiqiza ama-organic acid akhishwa emanzini83,84. Ngakho-ke, kwakheka indawo enolaka, ngaleyo ndlela kushintsha ama-Nb-MXenes. Ngaphezu kwalokho, ama-microalgae angashintsha i-pH yendawo ibe yi-alkaline ngenxa yokumuncwa kwe-carbon dioxide, okungadala nokugqwala79.
Okubaluleke kakhulu, isikhathi sokukhanya esimnyama/esisetshenziswe ocwaningweni lwethu sibalulekile ekuqondeni imiphumela etholakele. Lesi sici sichazwe ngokuningiliziwe ku-Djemai-Zoghlache et al. 85 Basebenzise ngamabomu isikhathi sokukhanya samahora ayi-12/12 ukukhombisa i-biocorrosion ehlotshaniswa ne-biofouling yi-red microalgae Porphyridium purpureum. Babonisa ukuthi isikhathi sokukhanya sihlotshaniswa nokuvela kwamandla ngaphandle kwe-biocorrosion, okuzibonakalisa njengokushintshashintsha kwe-pseudoperiodic cishe ngo-24:00. Lokhu okubonwe kwaqinisekiswa nguDowling et al. 86 Babonise ama-biofilms e-photosynthetic e-cyanobacteria i-Anabaena. I-oxygen encibilikisiwe yakhiwa ngaphansi kwesenzo sokukhanya, okuhlotshaniswa noshintsho noma ukuguquguquka kwamandla e-biocorrosion yamahhala. Ukubaluleka kwesikhathi sokukhanya kugcizelelwa iqiniso lokuthi amandla e-biocorrosion ayanda esigabeni sokukhanya futhi anciphe esigabeni sobumnyama. Lokhu kungenxa ye-oxygen ekhiqizwa yi-photosynthetic microalgae, ethonya ukusabela kwe-cathodic ngengcindezi engaphelele ekhiqizwa eduze kwama-electrode87.
Ngaphezu kwalokho, kwenziwa i-Fourier transform infrared spectroscopy (FTIR) ukuthola ukuthi ngabe kukhona yini ushintsho oluye lwenzeka ekwakhiweni kwamakhemikhali kwamaseli e-microalgae ngemva kokuxhumana nama-Nb-MXenes. Le miphumela etholakele iyinkimbinkimbi futhi siyethula ku-SI (Izibalo S23-S25, kufaka phakathi imiphumela yesigaba se-MAX kanye nama-ML MXenes). Ngamafuphi, ama-reference spectra atholakele e-microalgae asinikeza ulwazi olubalulekile mayelana nezici zamakhemikhali zalezi zinto eziphilayo. Lokhu kudlidliza okungenzeka kakhulu kutholakala kuma-frequency angu-1060 cm-1 (CO), 1540 cm-1, 1640 cm-1 (C=C), 1730 cm-1 (C=O), 2850 cm-1, 2920 cm-1. eyodwa. 1 1 (C–H) kanye no-3280 cm–1 (O–H). Ku-SL Nb-MXenes, sithole isiginesha sokwelula i-CH-bond esivumelana nesifundo sethu sangaphambilini38. Kodwa-ke, sibonile ukuthi ezinye iziqongo ezengeziwe ezihlotshaniswa nezibopho ze-C=C kanye ne-CH zanyamalala. Lokhu kubonisa ukuthi ukwakheka kwamakhemikhali kwe-microalgae kungase kushintshe kancane ngenxa yokusebenzisana ne-SL Nb-MXenes.
Uma kucatshangelwa izinguquko ezingaba khona ku-biochemistry ye-microalgae, ukuqongelela kwama-oxide angaphili, njenge-niobium oxide, kudinga ukucatshangelwa kabusha59. Kuhilelekile ekuthathweni kwezinsimbi ngumphezulu weseli, ukuthuthwa kwazo ziye kwi-cytoplasm, ukuhlangana kwazo namaqembu e-carboxyl angaphakathi kweseli, kanye nokuqongelela kwazo kuma-polyphosphosomes e-microalgae20,88,89,90. Ngaphezu kwalokho, ubudlelwano phakathi kwe-microalgae nezinsimbi bugcinwa amaqembu asebenzayo amaseli. Ngenxa yalesi sizathu, ukumuncwa nakho kuncike kumakhemikhali omphezulu we-microalgae, okuyinto eyinkimbinkimbi kakhulu9,91. Ngokuvamile, njengoba bekulindelekile, ukwakheka kwamakhemikhali kwe-microalgae eluhlaza kushintshe kancane ngenxa yokumuncwa kwe-Nb oxide.
Ngokuthakazelisayo, ukuvinjelwa kokuqala okubonwe kwe-microalgae kwaguqulwa ngokuhamba kwesikhathi. Njengoba sibonile, i-microalgae yanqoba ushintsho lokuqala lwemvelo futhi ekugcineni yabuyela emazingeni okukhula ajwayelekile futhi yanda ngisho nangokwengeziwe. Izifundo ze-zeta potential zibonisa ukuzinza okuphezulu lapho zifakwa kwimidiya yezakhamzimba. Ngakho-ke, ukusebenzisana kobuso phakathi kwamaseli e-microalgae nama-nanoflakes e-Nb-MXene kwagcinwa kulo lonke ucwaningo lokunciphisa. Ekuhlaziyeni kwethu okuqhubekayo, sifingqa izindlela eziyinhloko zesenzo ezisekela lo mkhuba omangalisayo we-microalgae.
Ukubonwa kwe-SEM kukhombisile ukuthi ama-microalgae avame ukunamathela kuma-Nb-MXenes. Sisebenzisa ukuhlaziywa kwesithombe okuguquguqukayo, siyaqinisekisa ukuthi lo mphumela uholela ekuguqulweni kwama-nanoflakes e-Nb-MXene anezinhlangothi ezimbili abe yizinhlayiya eziyindilinga, ngaleyo ndlela sibonisa ukuthi ukubola kwama-nanoflakes kuhlotshaniswa nokubola kwawo. Ukuze sihlole umbono wethu, senze uchungechunge lwezifundo zezinto ezibonakalayo kanye nezamakhemikhali. Ngemva kokuhlola, ama-nanoflakes ancipha kancane kancane futhi abola abe yimikhiqizo ye-NbO kanye ne-Nb2O5, engazange ibe yingozi kuma-microalgae aluhlaza. Sisebenzisa ukubonwa kwe-FTIR, asitholanga zinguquko ezibalulekile ekwakhiweni kwamakhemikhali kwama-microalgae afakwe lapho kukhona ama-nanoflakes e-2D Nb-MXene. Sicabangela amathuba okumuncwa kwe-niobium oxide yi-microalgae, senze ukuhlaziywa kwe-X-ray fluorescence. Le miphumela ikhombisa ngokusobala ukuthi ama-microalgae afundwe adla ama-niobium oxides (NbO kanye ne-Nb2O5), angewona ubuthi kuma-microalgae afundwe.