Background

In several applications of artificial photosynthesis, photocatalytic hydrogen evolution reaction can realize the conversion of light energy to hydrogen energy, showing great potential in achieving sustainable energy utilization. TiO₂ is the first photocatalyst used for photocatalytic hydrogen evolution. It has attracted much attention due to its stability and low cost. However, the original TiO₂ faces the problems of difficult charge excitation, low carrier utilization rate, and limited photocatalytic hydrogen production efficiency, which makes it challenging to achieve industrial demand.

Methods

This review summarizes strategies for the evolution of TiO₂ into natural photosystem based on thermodynamics and kinetics, including defect engineering, junction engineering, and cocatalyst engineering. Subsequently, other promising optimization strategies for photocatalytic systems were also reviewed. Finally, various problems in the industrialization of TiO₂ for photocatalytic hydrogen production were proposed.

Significant findings

It was found that the evolution of TiO₂ into a natural photosystem is an effective solution to improve its hydrogen evolution activity. Moreover, superior to the photosystem, its catalytic efficiency is allowed to be further improved by other optimization strategies such as introducing thermal effects. To design excellent TiO₂ for hydrogen evolution reaction, it is necessary to handle the development trend of these evolution strategies.