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

Abstract

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 (ATOÀ NR//TiO 2 ,//denotes heteroepitaxial junction) by a hydrothermal method. UV-light irradiation of ATOÀ 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 ATOÀ 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.

Antimony-Doped Tin Oxide Catalysts for Green and Sustainable Chemistry

“…(c) Koutecky–Levich plots for the current at E = −0.8 V vs Ag/AgCl. Figure reproduced with permission from ref . Copyright 2022 Wiley-VCH.…”

“…SnO 2 :Sb nanorods were grown from rutile TiO 2 NCs with a specific crystallographic orientation by a hydrothermal method (Figure 5a). 58 The high-resolution transmission electron spectroscopic (HR-TEM) image shows an atomically commensurate junction between SnO 2 :Sb and TiO 2 (Figure 5b). Further detailed analyses clarified that a heteroepitaxial junction with an orientation of (001) SnOd 2 //(001) TiOd 2 is formed as shown by the interface models (SnO 2 −NR//TiO 2 , // denotes heteroepitaxial junction) (Figure 5c and d).…”

“…SnO 2 :Sb nanorods were grown from rutile TiO 2 NCs with a specific crystallographic orientation by a hydrothermal method (Figure a) . The high-resolution transmission electron spectroscopic (HR-TEM) image shows an atomically commensurate junction between SnO 2 :Sb and TiO 2 (Figure b).…”

“…(g) Schematic representation of the SnO 2 :Sb NR//TiO 2 -photocatalyzed H 2 O 2 generation from ethanol aqueous solution. Parts (a), (b), (e), (f), and (g) are taken from ref . Copyright 2022 Wiley-VCH.…”

Recent advancements in modified SnO2–Sb electrodes for electrochemical treatment of wastewater

“…131 It has been shown that doping Sb into SnO 2 significantly enhances its electrocatalytic activity for the 2e − -ORR. 132 SnO 2 –Sb material (+0.299 V vs. SHE at pH = 0) cannot induce the 1e − -ORR, and the structure of this material is conducive to the reaction of 2e − -ORR. SnO 2 –Sb has attracted wide attention because of its H 2 O 2 yield.…”