High energy electron beam irradiated TiO₂ photoanodes for improved water splitting

Photoelectrochemical (PEC) water splitting holds great promise for harvesting solar energy. We found that the high energy electron beam irradiation has a strong influence on the photoelectrochemical water splitting performance of aerosol deposited (AD) TiO₂ thin films. A high energy electron beam with energy of 0.2 MeV was used for modifying the surface structure of TiO₂ thin films. The electron beam irradiated film showed an enhanced water splitting activity as compared to the non-irradiated, pure AD TiO ₂ films. The pure TiO₂ films produced a photocurrent density of ∼40 A cm^-2 at -0.8 V vs. Ag/AgCl, whereas the electron beam irradiated TiO₂ films showed a pronounced increase in the photocurrent density of ∼205 A cm^-2 at -0.8 V vs. Ag/AgCl under UV light illumination. The chemical composition, surface morphology and roughness of the AD films were investigated. The photoresponse characteristics of the films before and after the e-beam irradiation were compared. We demonstrated that the e-beam irradiation technology can effectively alter the surface micro and nanostructure of semiconductor photocatalysts to significantly improve the water splitting activity.