Characterization of Photoactivity of Nanostructured BiVO4 at Polarized Liquid–Liquid Interfaces by Scanning Electrochemical Microscopy

Abstract

Scanning electrochemical microscopy (SECM) has been used for recording the photoinduced charge-transfer reactions at bismuth vanadate (BiVO4) photocatalyst nanostructures arranged at chemically polarized liquid/liquid (L/L) interfaces between an organic butyronitrile electrolyte and an aqueous electrolyte containing perchlorate as common anion. In addition, [Co(bpy)3](PF6)3 soluble in the organic phase was used as a probe of SECM analysis but also as a sacrificial agent, which effectively improves the separation efficiency of photogenerated charge carriers at the BiVO4 modified L/L interface. The nanoassembled layer did not require contact to a current collector. Interfacial polarization effects on the photoinduced charge-transfer reactions have been investigated by recording the regeneration of the reduced form [Co(bpy)3](PF6)2 at the BiVO4 particle layer in organic phase in SECM feedback approach curves. The kinetic parameters of the interfacial photoinduced electron transfer (ET) reaction have been ana...