Fabrication and behaviors of CdS on Bi2MoO6 thin film photoanodes

Abstract

Most Bi-based photoelectrodes have suitable band gaps and can effectively promote hydrogen evolution from water splitting, but there are few studies up to now for simple preparation methods for Bi-based binary metal oxides as photoanodes. Here, we prepared a novel Bi₂MoO₆ thin film photo-anode without a template; our preparation methods of Bi-based binary metal oxides with controlled morphologies were conducted by growing the Bi₂MoO₆ directly on an electrical substrate via an in situ growth process. The photoanodes show well-shaped thin film morphologies and exhibit impressive photoelectrochemical properties compared to the Bi-based photoanodes synthesized by conventional methods. A 2× enhanced photocurrent was obtained when the Bi₂MoO₆ thin film photoanodes were modified with CdS in comparison with the primary Bi₂MoO₆ (about 0.85 mA cm⁻²) under identical conditions. The enhanced photoelectrochemical properties were studied using several techniques including SEM, XRD, XPS, UV-vis diffuse reflectance, etc. and the results were in good agreement with each other. Moreover, the Bi₂MoO₆ thin film photoanodes possess long-term stability under solar irradiation and show a considerable photocurrent.