Development of a Potential Fe₂O₃-Based Photocatalyst Thin Film for Water Oxidation by Scanning Electrochemical Microscopy: Effects of Ag−Fe₂O₃ Nanocomposite and Sn Doping

Abstract

Ag−Fe 2 O 3 and Sn-doped Ag−Fe 2 O 3 nanocomposite photocatalysts were optimized by scanning photoelectrochemical microscopy (SPECM) as a potential photoelectrochemical material for visible light irradiation (λ ≥ 420 nm). The photocurrent vs potential response and the action spectra were investigated in a three-electrode cell. Among different mole ratios, the composition of nanocomposite with 50% Ag−50% Fe (atomic percentage) showed a dramatic improvement in photocurrent on a thin film electrode under visible light (λ ≥ 420 nm). The addition of 2 atomic % Sn (relative to Fe) produced an Ag−Fe 2 O 3 nanocomposite with the largest photocurrent in alkaline solution under visible light irradiation (λ ≥ 420 nm).