Titanium Oxide-Based Noble Metal-Free Core-Shell Photocatalysts for Hydrogen Production
Résumé
Photocatalytic and photo-electrocatalytic production of hydrogen from water is considered as a promising solution for solar energy storage issue. The feasibility of solar fuel technologies depends on the performance of catalysts, which should meet several strict requirements. They should be active under the solar light, chemically and photochemically stable, nontoxic, and cost-effective. In this view, preparation of effective photocatalysts from earth-abundant elements is of great importance for sustainable energetics. Among the large variety of photocatalysts studied during the past decades, the catalysts based on titanium oxide have attracted much attention. However, a quite large bandgap and rapid electron-hole recombination are the serious bottlenecks of TiO2photocatalyst. The recent advances in photocatalysis with TiO2-based materials pointed out several strategies of TiO2bandgap engineering, such as doping of TiO2 with cations or anions and surface sensitization with organic dyes or transition metal complexes. On the other hand, fabrication of TiO2heterojunctions with other semiconductors and TiO2 loading with cocatalysts allows to minimize electron-hole recombination during the photocatalytic process. Design of catalyst morphology is an important strategy to reach maximal photocatalytic activity. This chapter is primarily focused on titania-based core-shell photocatalysts fabricated from earth-abundant elements for efficient and cost-effective hydrogen production. Special attention is also paid to the photothermal effect in solutions, which has recently been proven to be promising for more efficient photocatalytic solar light conversion.