LAUSR

Abstract Sn 2 Nb 2 O 7 photoanode has been fabricated by the electrophoretic deposition method and its photoelectrochemical (PEC) properties were studied carefully. The energy band structure of Sn 2 Nb 2 O 7 was analyzed by Mott-Schottky plots, the results show that its energy band structure matches the requirement of PEC water splitting, the low absolute onset potential of −0.12 V vs NHE achieved with the Sn 2 Nb 2 O 7 /Co-Pi. The influence of film thickness and calcination temperature on the photocurrent of Sn 2 Nb 2 O 7 was studied, and an optimum condition was identified. The obtained maximum photocurrent density was 0.18 mA/cm 2 . After surface modification with the water-oxidation electrocatalyst Co-Pi, the photocurrent density was improved furtherly, reached to 0.24 mA/cm 2 , and the incident photon current efficiency (IPCE) value increased to 2.25% when irradiated by 365 nm light. Water oxidation was carried out over Sn 2 Nb 2 O 7 photoanode, the evolved oxygen reached to 3.5 μmol within 100 min at the experimental conditions. Electrochemical impedance spectroscopy has been performed to investigate the kinetics of electrolyte and electrode interface.