Bismuth Vanadate with Electrostatically Anchored 3D Carbon Nitride Nano‐networks as Efficient Photoanodes for Water Oxidation

Abstract

In this study, we report a photoanode consisting of a polymeric/inorganic nanojunction between novel nanostructured 3D C₃ N₄ nano-networks and BiVO₄ substrate. This nanojunction is formed such that 3D C₃ N₄ nano-networks with a positively charged surface are efficiently anchored on the BiVO₄ photoanode with a negatively charged surface. This electrostatic self-assembly can initiate and contribute to an intimate contact at the interfaces, leading to an enhanced photoelectrochemical activity and stability compared with that fabricated by non-electrostatic assembly. The C₃ N₄ nano-network/BiVO₄ photoanode achieved a remarkable photocurrent density of 4.87 mA cm^-2 for water oxidation at 1.23 V (vs. reversible hydrogen electrode) after depositing FeOOH/NiOOH as oxygen-evolution co-catalyst, which is among the highest photocurrent densities reported so far for BiVO₄ -based photoanodes.