Development of a potential Fe₂O₃-based photocatalyst thin film for water oxidation by scanning electrochemical microscopy: Effects of Ag-Fe₂O₃ nanocomposite and Sn doping

Ag-Fe₂O₃ and Sn-doped Ag-Fe₂O₃ 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-Fe₂O₃ nanocomposite with the largest photocurrent in alkaline solution under visible light irradiation (λ ≥ 420 nm).