Fabrication of Z-Scheme WO3/KNbO3 Photocatalyst with Enhanced Separation of Charge Carriers

Z-Schemc photocatalysts as a research locus pertomi strong redox capability and high photocatalytic peribnnance.WO3/KNbO3 photocatalysts were fabricated by ball milling method,and performed higlier photocatalytic activity in liquid degradation(rhodamine B,methylene blue and bisphenol A),compared with WO3 or KNbO3 monomer.This is due to that Z-scheme heterojunction is lonned between WO3 and KNbO3,and the holes photo-excited in valence band of KNbO?are quickly combined with the electrons in conduction band of WO3.The electrons accumulated in conduction band of KNbO3 show high reducibility,thereby reducing O2 to·O 2-,and the holes in valence band of WO3 show high oxidative to oxidize H2O to·OH,respectively.Furthermore,it is proved by means of electron spin resonaiice(ESR)spectra,terephthalic acid photolumiiiescence probing technique(TA・PL),and UV-Vis absorption spectra of nitroblue tetrazolium.This work indicates that the iabrication of Z-scheme structure can improve the photocatalytic activity by efficiently separating the photogenerated electrons and holes in the photocatalytic reaction system,which is helpful to deeply understand the migration mechanism of photoexcited cairier(band-band transfer and Z-scheme transfer)in heterojunction photocatalysts.