High energy electron beam irradiated TiO2 photoanodes for improved water splitting

Abstract

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 TiO₂ films. The pure TiO₂ films produced a photocurrent density of ∼40 µA 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 µA 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.