Preparation of Surface Dispersed WO/BiVO Heterojunction Arrays and Their Photoelectrochemical Performance for Water Splitting.

In this work, a surface dispersed heterojunction of BiVO-nanoparticle@WO-nanoflake was successfully prepared by hydrothermal combined with solvothermal method. We optimized the morphology of the WO nanoflakes and BiVO nanoparticles by controlling the synthesis conditions to get the uniform BiVO loaded on the surface of WO arrays. The phase composition and morphology evolution with different reaction precursors were investigated in detail. When used as photoanodes, the WO/BiVO composite exhibits superior activity with photocurrent at 3.53 mA cm for photoelectrochemical (PEC) water oxidation, which is twice that of pure WO photoanode. The superior surface dispersion structure of the BiVO-nanoparticle@WO-nanoflake heterojunction ensures a large effective heterojunction area and relieves the interfacial hole accumulation at the same time, which contributes to the improved photocurrents together with the stability of the WO/BiVO photoanodes.