Nanostructured TiO2 for improving the solar-to-hydrogen conversion efficiency

Learning from nature's complex photosynthesis process and leaf architecture, it appears, in a simplified picture, that light-harvesting, photogenerated charge carrier separation and their lifetimes, and surface photocatalyst reactivity are among the key challenges to the efficient conversion of solar energy to chemical fuel. Improving the photocatalytic efficiency of a photocatalytic material requires: (i) prolonging the lifetime of the photogenerated charges carriers, (ii) broadening the spectrum of absorption response and enhancing the ability of photon absorption (light-harvesting properties), and (iii) promoting the surface reactivity. In this review, we expose the effects of dimensionality on the photocatalytic performance of TiO2 from the structural design perspective. We initially introduce the main factors affecting the performance of artificial TiO2 photocatalyst. Then, we focus on summarizing different dimensional structures of TiO2 and the effect of dimensionality on photocatalytic activity. Finally, we outline the challenges and provide perspectives for future research.