Construction of BiVO4 nanosheets@WO3 arrays heterojunction photoanodes by versatile phase transformation strategy

Abstract A versatile phase transformation strategy was proposed to synthesize novel BiVO4 nanosheets (NSs)@WO3 nanorod (NR) and nanoplate (NP) arrays films. The strategy was carried out by following a three-step hydrothermal process (WO3→WO3/Bi2WO6→WO3/BiVO4). According to the characterization results, plenty of BiVO4 NSs grew well on the surface of WO3 NR and NP arrays films, thus forming the WO3/BiVO4 heterojunction structure. The prepared WO3/BiVO4 heterojunction films were used as the photoanodes for the photoelectrochemical (PEC) water splitting. As indicated by the results, the photoanodes exhibited an excellent PEC activity. The photocurrent densities of the WO3/BiVO4 NR and NP photoanodes at 1.23 V (vs RHE) without cocatalyst under visible light illumination reached up to about 1.56 and 1.20 mA/cm b respectively.