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

The performance of BiVO 4 photoanodes, especially under front-side illumination, is limited by the modest charge transport properties of BiVO 4 . Core/shell nanostructures consisting of BiVO 4 coated onto a conductive scaffold are a promising route to improving the performance of BiVO 4 -based photoanodes. Here, we investigate photoanodes composed of thin and uniform layers of BiVO 4 particles coated onto Sb-doped SnO 2 (Sb:SnO 2 ) 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 (η abs × η sep ) of ∼57.3 and 58.5% under front- and back-side illumination, respectively, at 0.6 V RHE . Moreover, both of these high η abs × η sep efficiencies are achieved without any extra treatment or intentional doping in BiVO 4. These results indicate that integration of Sb:SnO 2 nanotube cores with other successful strategies such as doping and hydrogen treatment can increase the performance of BiVO 4 and related semiconductors closer to their theoretical potential.