Noble Metal-Free Inorganic Photocatalyst Consisting of Antimony-Doped Tin Oxide Nanorod and Titanium oxide for Two-Electron Oxygen Reduction Reaction.

This study reports a noble metal-free robust inorganic photocatalyst for H 2 O 2 synthesis via two-electron oxygen reduction reaction (ORR). Antimony-doped tin oxide nanorods were heteroepitaxially grown from rutile TiO 2 seed crystals with an orientation of (001) ATO //(001) TiO2 (ATO-NR//TiO 2 ,//denotes heteroepitaxial junction) by a hydrothermal method. UV-light irradiation of ATO-NR//TiO 2 particles stably and continuously produces H 2 O 2 from aerated aqueous solution of ethanol. Electrochemical measurements using rotating electrodes show that Sb-doping into SnO 2 greatly enhances the electrocatalytic activity for two-electron ORR. The striking photocatalytic activity of ATO-NR//TiO 2 stems from the effective charge separation, electrocatalytic activity for two-electron ORR, low catalytic activity for H 2 O 2 decomposition, and extraordinary robustness.