Utilizing transparent and conductive SnO2 as electron mediator to enhance the photocatalytic performance of Z-scheme Si-SnO2-TiOx

Z-scheme photocatalysts,with strong redox ability,have a great potential for pollutants degradation.However,it is challenging to construct efficient Z-scheme photocatalysts because of their poor interfacial charge separation.Herein,by employing transparent and conductive SnO2 as electron mediator to pass light through and promote interfacial charge transportation,a novel Z-scheme photocatalyst Si-SnO2-TiOx(i<x<2)was constructed.The Z-scheme photocatalyst displayed an order of magnitude higher photocurrent density and a 4-fold increase in open-circuit potential compared to those of Si.Moreover,the onset potential shifted negatively for approximately 2.2 V.Benefiting from these advantages,this Z-scheme Si-SnO2-TiOx exhibited efficient photocatalytic performance toward phenol degradation and mineralization.15%of the phenol was degraded without bias potential and 70%of the TOC was removed during phenol degradation.Other typical pollutants such as bisphenol A and atrazine could also be degraded without bias potential.Introducing a transparent and conductive electron mediator to construct Z-scheme photocatalyst gives a new sight to the improvement of photocatalytic performance in Z scheme.