Ukubola kwemethylene blue kunye nefotokatalisisi: ukutolika iziphumo zokususwa

Ilabhoratri ivavanya iikatalisti ezimbini zokubola kwemethylene blue ngefotokatalisisi. Ikatalisti A isusa 95 ekhulwini lombala oluhlaza okwesibhakabhaka ngeyure enye. Ikatalisti B ikwazi ukususa 60 ekhulwini kuphela. Iqela libhengeza u-A njengophumeleleyo, libhale oko kwingxelo, lize liodole enye engakumbi. Kwiinyanga kamva, uhlalutyo lwekhabhoni lubonisa inyaniso: inkoliso yedayi eyasuswa ngu-A yayihleli ingatshintshanga kumphezulu wento eqinileyo, ngoxa u-B wayeqhekeze iimolekyuli zedayi ezininzi ngakumbi. Uhlelo lwalujikwe kuba iqela lalilinganise ingcamango enye laza layithiya ngegama lenye.

Le mpazamo ixhaphakile kuba iingcamango ezine ezahlukeneyo zinento enye ebonakalayo: umbala wolwelo oluhlaza okwesibhakabhaka uya usiba buthuntu. Ukuncamathela kumphezulu, ukuphela kombala, ukubola, nokuguqulwa kube ziiminerali nganye inokwenza eso siphumo, yaye nganye ibanga into eyahlukileyo malunga nokwenzeke kwidayi. Imethylene blue yenye yezinto ezisetyenziswa kuhlalutyo nakuphando lokusingqongileyo apho idayi inendima echaziweyo, yaye apha indima yayo kukuba sisingcolisi esingumzekelo esisuswayo okanye esitshintshwayo. Ngaphambi kokuthelekisa iikatalisti okanye ukupapasha ipesenti yokususwa, gqiba ukuba sesiphi isiphelo ezinokusixhasa ngokwenene izilinganiso zakho.

Iziphelo ezine, amabango amane ahlukeneyo

Zicinge njengeengcamango ezine ezinemigaqo yokusebenza eyahlukeneyo. Nganye iphendula umbuzo owahlukileyo, yaye nganye ifuna ubungqina bayo.

Ukuncamathela kumphezulu kuthetha ukuba iimolekyuli zedayi zishiya isisombululo zize zihlale kwinto eqinileyo, ngaphandle kokuba zitshintshe ngokwekhemikhali. Uvavanyo lwako lwenziwa ebumnyameni de ukufunxwa kumphezulu kufikelele kwinqanaba elizinzileyo lokwenene, yaye ubungqina obunyanisekileyo buquka idayi efunyenwe kwinto eqinileyo ngokuyikhulula kumphezulu okanye ngokuyikhupha. Ixesha elimiselweyo lemizuzu eyi-30 ebumnyameni alibobungqina bolungelelwano kuyo yonke imathiriyeli, yaye ingxoxo yakutshanje yeendlela zophando ibonisa indlela ukutsiba eli nyathelo okuvelisa ngayo ukuhlelwa kwekatalisti okungeyonyani xa ukufunxwa ebumnyameni kwahlukile phakathi kweemathiriyeli.

Ukuphela kombala kuthetha ukulahleka kweqela lemolekyuli elivelisa umbala obonakalayo, ekudla ngokulandelelwa kufuphi nebhanti eliphambili lokufunxwa kokukhanya elikwi-664 nm. Ukuncamathela kumphezulu, ukwamkela ii-elektroni, ukususwa kwamaqela e-methyl kwi-N, kunye nokuqhekeka kweqela elivelisa umbala konke kungalithoba elo nani lifundwayo, ngoko ixabiso elikubude bamaza obunye alinako ukuchaza unobangela. Rekhoda iispektra ezipheleleyo endaweni yenani elinye: ukushenxa kwencopho ukuya kubude bamaza obufutshane kuyahambelana neemveliso zosapho lwe-Azure ezisuswe amaqela e-methyl. Isiphumo esichazwa njenge-95 ekhulwini yokususwa kwi-664 nm kufuneka sibizwe ngokuba yi-95 ekhulwini yokuphela kombala, hayi i-95 ekhulwini yokubola.

Ukubola kuthetha ukuba imolekyuli yemethylene blue yokuqala itshintshwe ngokwekhemikhali. Ubungqina buvela kwikromatografi: idayi engatshintshanga iyanyamalala kwi-HPLC okanye kwi-UPLC ngoxa iimveliso zenguqu zibonakala zize nazo zibole, yaye kungcono ukuba zichongwe nge-LC-MS. Izalathisi eziluncedo ziquka i-ion yemolekyuli ekufuphi ne-m/z 284 yedayi yokuqala kunye nolandelelwano lokususwa kwamaqela e-methyl ngokwamanqanaba: i-Azure B ekufuphi ku-270, i-Azure A ekufuphi ku-256, i-Azure C ekufuphi ku-242, kunye nethionine ekufuphi ku-228, apho kuye kwapapashwa utshintsho lwe-LC-MS/MS oluqinisekisiweyo lweedayi ezisemanzini.

Ukuguqulwa kube ziiminerali kuthetha ukuba ikhabhoni ye-organic iguqulwe yaba ziimveliso zokugqibela ze-inorganic, ikakhulu ikharbon dayokside kunye nekhabhoni ye-inorganic, ngoxa initrogen nesalfure ziphela kwiintlobo ezifana ne-ammonium, initrate, nesulfate. Ukulahleka kwekhabhoni ye-organic iyonke (TOC) ngumlinganiselo wekhabhoni osetyenziswa rhoqo. Ukuncipha kwemfuno yeoksijini yeekhemikhali (COD) kubonisa ukuhla komthamo wezinto ezinokwenziwa i-oxidation, kodwa akuyobalansi yobunzima bekhabhoni yaye kona kuphela akubonisi ukuguqulwa ngokupheleleyo kube ziiminerali. Ikromatografi yee-ion yesulfate, initrate, ne-ammonium iyaliqinisa ibango.

Iintlobo zeekatalisti (ititania efakwe ezinye izinto, imathiriyeli eyintlanganisela, iimathiriyeli ezixhaswe yikhabhoni, nezinye ezifana nazo) zifanele ukuthelekiswa kunye kuphela xa uhlobo ngalunye ludlula kwiziphelo neemvavanyo zolawulo ezifanayo. Imathiriyeli eyintlanganisela encamathelisa idayi ngamandla iya kusoloko ibonakala ikhawuleza kuvavanyo lombala, yaye seso sizathu kanye esenza ukuba uluhlu lokukhangela olungezantsi lwahlule ukufunxwa kumphezulu kwimpendulo yekhemikhali ngaphambi kokuhlela.

Indlela esebenza ngayo ifotokatalisisi ekuboleni kwemethylene blue

Iindlela ezamkelweyo zokuvuselelwa kokwenene kwesemikhondaktha zishwankathelwe kuphononongo lokubola kweedayi ngefotokatalisisi kwiimathiriyeli ezisekelwe kwititania olucatshulwa kakhulu. Iifotoni ezifunxiweyo zivelisa ii-elektroni kwibhanti yokuqhuba kunye nezikhewu kwibhanti yevalensi. Izikhewu zenza i-oxidation yamanzi akumphezulu okanye ye-hydroxide zibe ziiradikhali ze-hydroxyl, ngoxa ii-elektroni zinika ioksijini enyibilikileyo ii-elektroni ukuze ibe yi-superoxide; ezinye iimpendulo zekhemikhali ezidlula kwiiradikhali ze-hydroperoxyl nakwihydrogen peroxide zivelisa ezinye iiradikhali ze-hydroxyl. Ezi ntlobo zeoksijini ezisabela ngamandla kunye nezikhewu ngokwazo zihlasela idayi.

Inguqu yemethylene blue idla ngokuqala ngokususwa kwamaqela e-methyl kwi-N ngokulandelelana, kudlulwa kwi-Azure B, i-Azure A, ne-Azure C ukuya kwithionine, kunye ne-oxidation yeqela lephenothiazine elivelisa umbala. Ukuhlasela okungakumbi kweeradikhali kuqhawula iibhondi zekhabhoni nesalfure kunye nezekhabhoni nenitrogen, kuvule izangqa ezinevumba elimnandi, kuze kuvelise iikhompawundi zohlobo lwephenol ne-aniline, iialdehyde, kunye neeasidi zekhaboksili ezinobunzima obuphantsi bemolekyuli ngaphambi kokuguqulwa kube ziiminerali ekugqibeleni. Uphononongo olugxile kwiimpawu zemethylene blue nakwiindlela zokubola kwayo ngokukhanya luchaza olu sapho lweendlela ngokweenkcukacha. Umlinganiselo ochanekileyo wesebe ngalinye uxhomekeke kwikatalisti, kwi-pH, kunikezelo lweoksijini, nakukukhanyiswa, ngoko yithathe le nkqubo njengosapho lweendlela kunokuba ibe lulandelelwano olunye olunyanzelekileyo.

Izinto ezimbini zovavanyo zifuna ingqalelo kuba zitshintsha isantya esibonakalayo sempendulo ngaphandle kokutshintsha ikatalisti ngokwayo. I-pH itshintsha itshaji yombane kumphezulu wetitania kunye nokubakho kwamaqela e-hydroxyl kumphezulu, nto leyo etshintsha ukuncamathela kwidayi ene-ion enetshaji evumayo, ngoko ke itshintshe nesantya esibonwayo; thelekisa iimathiriyeli kwi-pH efanayo uze urekhode amaxabiso okuqala nawokugqibela. Iityuwa ezinyibilikileyo kunye nezithinteli zotshintsho lwe-pH zisebenza ngendlela efanayo: ichloride, iphosphate, icarbonate, nesulfate zinokuthatha iziza ezikumphezulu zize zitshintshe iimpendulo zekhemikhali zeeradikhali, yaye uphando olugxile kwiityuwa ze-inorganic kwifotokatalisisi yetitania lubhala ngokuthe ngqo ngesiphumo kwimethylene blue.

Umgibe wokukhanya okubonakalayo

Ititania engatshintshwanga ifuna ukuvuselelwa kukukhanya okukufuphi ne-UV, kodwa iingxelo ezininzi zibonisa ukuphela kombala wemethylene blue phantsi kwezibane ezikhupha ukukhanya okubonakalayo kuphela, zize zithi ikatalisti iyasebenza ngokukhanya okubonakalayo. Indlela enokwenzeka kukuvuselelwa yidayi: idayi evuselelweyo ifaka i-elektroni kwisemikhondaktha, ize loo elektroni inike ioksijini i-elektroni, iphelise umbala ngaphandle kokuvuselelwa kokwenene okunqumla umsantsa phakathi kweebhanti kwinto eqinileyo. Umsebenzi wovavanyo ogcinwe ngu-Ohtani noogxa bakhe malunga nengxaki yokukhanya okubonakalayo wabonisa esi siphumo silahlekisayo, yaye inkcazo yomda we-ISO 10678 iyawucacisa lo mda ngokukhawulela indlela yayo yokuvavanya imethylene blue kukukhanyiswa nge-UV, ingawamkeli amabango okusebenza ngokukhanya okubonakalayo.

Uvavanyo olusebenzisekayo lulula. Phinda uvavanyo ngento yokuvavanya engenambala nengakufunxiyo ukukhanya okubonakalayo, uze uthelekise indlela isantya esixhomekeke ngayo kubude bamaza nespektra yokufunxwa kokukhanya yekatalisti. Ukuba ukusebenza kulandela ukufunxwa kokukhanya yidayi endaweni yokufunxwa yikatalisti, isiphumo sixhasa ukuvuselelwa yidayi, hayi ifotokatalisisi yokukhanya okubonakalayo evela kwiimpawu zekatalisti ngokwayo. Gcina olu vavanyo engqondweni xa ufunda amabango abathengisi ngeentlobo zeekatalisti zokukhanya okubonakalayo.

Uluhlu lokukhangela iziphelo

Sebenzisa olu luhlu ngaphambi kokuhlela iikatalisti okanye ukubhala ibango lokususwa. Lusisixhobo seli phepha esinokusetyenziswa kwakhona: lonke uvavanyo lokubola kwemethylene blue kufuneka luphumelele kuwo wonke umba.

1. Uvavanyo lolawulo lokuncamathela ebumnyameni: idayi kunye nekatalisti, kungekho kukhanya, zixutywe de kufikelelwe kwinqanaba elizinzileyo elilinganisiweyo, kunye nokubuyiswa kwidayi ekwisigaba esiqinileyo, kungaqikelelwa ngexesha elimiselweyo.
2. Uvavanyo lolawulo lokubola ngokukhanya kuphela: idayi kunye nokukhanya, kungekho katalisti, ukulinganisa ukuphela kombala ngokuthe ngqo phantsi kwesibane sakho nakulungelelwaniso lwezixhobo zakho.
3. Isampulu yohlalutyo engenayo idayi: ikatalisti kunye nokukhanya, kungekho dayi, ukuze kubanjwe imiqondiso yangasemva kwi-TOC, kwii-ion, nakwiispektra.
4. Iimeko zempendulo ezingatshintshiyo: ispektra yesibane, ukuhamba kweefotoni, ubushushu, ukuxutywa, ioksijini enyibilikileyo, imilo nobukhulu besixhobo sempendulo, uxinaniso lokuqala lwedayi, ubungakanani bekatalisti, i-pH, kunye nobume besampulu zigcinwa zifana kuzo zonke iintlobo.
5. Ukwahlula into eqinileyo ngaphambi kwespektroskopi: hluza okanye usebenzise isixhobo esijikelezisa ngesantya esiphezulu ukuze ukusasazeka kokukhanya kungafundwa njengokufunxwa kokukhanya.
6. Iispektra ezipheleleyo, hayi ubude bamaza obunye: xela iskeni ukuze ukushenxa kweencopho namabhanti amatsha kuhlale kubonakala.
7. Ukuqinisekiswa ngekromatografi kulo naliphi na ibango lokubola: ukulahleka kwidayi yokuqala engatshintshanga kunye neemveliso ezilandelelweyo.
8. Ukubalwa kwekhabhoni kulo naliphi na ibango lokuguqulwa kube ziiminerali: i-TOC kunye neesampulu ezingenanto ekujoliswe kuyo, nokukhangela ukuba ikhabhoni ebalwe njengelahlekileyo ayifudukelanga nje kwinto eqinileyo.
9. Ukukhangela ukunyibilika kwezinto eziphuma kwikatalisti: susa into eqinileyo ngokupheleleyo (uvavanyo olufana nokuhluza kushushu), khanyisa ulwelo oluhluziweyo, uze uhlalutye iintsimbi ezinyibilikileyo; ukuqhubeka kwempendulo kubonisa igalelo lezinto ezikwisigaba esinye nesisombululo.
10. Ukuthiywa okunyanisekileyo: biza isiphumo se-664 nm ngokuphela kombala, isiphumo sekromatografi ngokubola, nesiphumo se-TOC ngokuguqulwa kube ziiminerali.

Uphononongo lwangoku lwesixhobo sempendulo yokukhanya se-UV-LED oludibanisa iimvavanyo zokuncamathela kumphezulu, ukwahlulwa kwekatalisti, i-UV-vis, ne-TOC lubonisa indlela la manqanaba adibana ngayo kwicandelo elinye leendlela zophando.

Umzekelo obaliweyo webhalansi yobunzima

Masithi uvavanyo lwe-100 mL luqala kwi-10 mg/L yemethylene blue, ngoko isixhobo sempendulo sine-1.0 mg yedayi. Emva kokufikelela kulungelelwano ebumnyameni, isisombululo sifundeka njenge-8.0 mg/L, nto leyo ethetha ukuba i-0.2 mg ihleli kwinto eqinileyo yaye i-0.8 mg ihlala inyibilikile. Emva kweyure enye yokukhanyiswa, uhlalutyo lwesisombululo esihluziweyo lubonisa i-2.0 mg/L yedayi engatshintshanga ngekromatografi (i-0.2 mg kwisisombululo), ukukhulula idayi kumphezulu kubuyisa i-0.1 mg yedayi engatshintshanga kwinto eqinileyo, yaye i-TOC ibonisa ukuba i-40 ekhulwini yekhabhoni ye-organic yokuqala iyishiyile inkqubo edibanisa isisombululo nento eqinileyo njengekhabhoni ye-inorganic.

Ibhalansi esekelwe kwikhabhoni ifundeka ngolu hlobo: ikhabhoni yokuqala ilingana nedayi yokuqala ekwisisombululo kunye nedayi yokuqala encamathele kumphezulu kunye neemveliso eziphakathi ze-organic kunye nekhabhoni eguqulwe yaba ziiminerali. Apha i-20 ekhulwini yobunzima bedayi yokuqala ihlala iyidayi yokuqala engatshintshanga (i-0.2 mg kuzo zombini izigaba), i-40 ekhulwini iguqulwe yaba ziiminerali, yaye i-40 ekhulwini eseleyo ziimveliso zenguqu ze-organic (iimveliso eziphakathi ezikwisisombululo okanye kwinto eqinileyo, eziqinisekiswa ziincopho zeemveliso). Ingxelo echanekileyo yi-80 ekhulwini yokubola kwidayi yokuqala kunye ne-40 ekhulwini yokuguqulwa kube ziiminerali, hayi i-95 ekhulwini yayo nayiphi na into. Qaphela umgibe: ukuba i-TOC ibilinganiselwe kulwelo olungaphezulu oluhluziweyo kuphela, izinto ze-organic ezincamathele kumphezulu bezinokubalwa njengezitshatyalalisiweyo zize zinyuse inani lokuguqulwa kube ziiminerali. Linganisa ikhabhoni kuwo wonke umxube wolwelo nezinto eziqinileyo apho kunokwenzeka khona, okanye wongeze ngokucacileyo kwakhona inxalenye ebotshelelwe kwinto eqinileyo.

Umgaqo wokunika ingxelo

Chaza esona siphelo sibuthathaka esixhaswa bubungqina bakho, uze wongeze amabango anamandla kuphela xa inqanaba ngalinye lezilinganiso liphumelela. Umsebenzi wokubola kwemethylene blue uzuza ukuthenjwa ngendlela efanayo nezinye iindlela ezisekelwe kwidayi: ngokutshatisa isiphumo nophawu olulinganiswa ngokwenene yindlela leyo. Isikhokelo esihambisana nesi sokufunda amabango ophando olusekelwe kwidayi sandisa olu qeqesho lunye kuyilo lophando, yaye inkqubo esebenzisekayo yokukhangela iimeko zovavanyo ichaza imikhwa yokulinganisa izixhobo enokusetyenziswa ngokuthe ngqo kumsebenzi wezixhobo zempendulo yokukhanya.