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 (lambda >= 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 (lambda >= 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 (lambda >= 420 nm).