Photoanode with Enhanced Performance Achieved by Coating BiVO4 onto ZnO-Templated Sb-Doped SnO2 Nanotube Scaffold.

The performance of BiVO4 photoanodes, especially under front-side illumination, is limited by the modest charge transport properties of BiVO4. Core/shell nanostructures consisting of BiVO4 coated onto a conductive scaffold are a promising route to improving the performance of BiVO4-based photoanodes. Here, we investigate photoanodes composed of thin and uniform layers of BiVO4 particles coated onto Sb-doped SnO2 (Sb:SnO2) nanotube arrays that were synthesized using a sacrificial ZnO template with controllable length and packing density. We demonstrate a new record for the product of light absorption and charge separation efficiencies (ηabs × ηsep) of ∼57.3 and 58.5% under front- and back-side illumination, respectively, at 0.6 VRHE. Moreover, both of these high ηabs × ηsep efficiencies are achieved without any extra treatment or intentional doping in BiVO4. These results indicate that integration of Sb:SnO2 nanotube cores with other successful strategies such as doping and hydrogen treatment can increase the performance of BiVO4 and related semiconductors closer to their theoretical potential.