Remarkable variation of visible light photocatalytic activities of MiSn0.9Sb0.1O2/TiO2 (M=Au, Ag, Pt) heterostructures depending on the loaded metals

Sn0.9Sb0.1O2/TiO2 (ATO/TiO2) heterostructure is a potential visible light photocatalysts that function via an inter-semiconductor hole-transport mechanism. Herein we selectively deposited Au, Ag, or Pt onto the ATO surface of ATO/TiO2 to investigate charge-trapping behaviors of the noble metals and their effects on photocatalytic performance. We observed that Pt deposition greatly enhanced the photocatalytic activity whereas effects of Au or Ag depositions were not significant. The result of spectroscopic analysis also indicates that Pt is the most effective in scavenging the electrons from the ATO CB. Particularly, Pt/ATO/TiO2 (ATO:TiO2 = 15:85 in weight) produced CO2 of 42 ppmv in 2 h, which is 16 times and 4.8 times that of bare ATO/TiO2 and nitrogen-doped TiO2 , respectively. Pt deposition on the ATO seems to suppress two independent charge recombination pathways, that is, recombination of electron-hole pairs in ATO and electron transport from the ATO CB to TiO2 VB. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study found that Pt deposition greatly enhances the photocatalytic activity of ATO/TiO2, while Au or Ag depositions have less significant effects. Spectroscopic analysis indicated that Pt is most effective in scavenging electrons from the ATO CB. Pt/ATO/TiO2 produced significantly more CO2 than other catalysts, suggesting that Pt deposition can suppress charge recombination pathways effectively.