Particulate Oxynitride Photoanodes Assembled with Transparent Electron-Collecting Oxide Nanorod Arrays

The collection of photogenerated electrons is commonly a bottleneck in photoelectrochemical water oxidation on a particulate photoanode. Herein, a new strategy called "array insertion" for particulate photoanode preparation is proposed to improve electron collection. ZnO nanorod arrays are inserted between LaTiO₂N particles and Al-doped ZnO (AZO) substrates via epitaxial electrodeposition, which make electronic connections. Using this methodology, charge separation efficiency is improved drastically, and the photocurrent at 1.23 V_RHE is enhanced by more than 1 order of magnitude, because the obstacle of electron collection in the particulate LaTiO₂N photoanodes is overcome.