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 VRHE is enhanced by more than 1 order of magnitude, because the obstacle of electron collection in the particulate LaTiO2N photoanodes is overcome.