Exploring the green technique based on photocatalysis to produce hydrogen peroxide: Progress and challenge

As a renewable energy carrier and an environmental-friendly oxidant, hydrogen peroxide (H2O2) has attracted widely attention. In comparison with conventional anthraquinone process, photocatalytic H2O2 generation is a sustainable, simple, safe, and green process, so there is a growing body of research on photocatalytic H2O2 generation. In this review, the progress and challenge of photocatalytic H2O2 generation are summarized, including the main mechanism of photocatalytic H2O2 synthesis, and design and modification principles of photocatalyst. Notably, the main issues facing photocatalytic H2O2 synthesis are low utilization of solar energy, high recombination rate of electron-hole pairs, poor selectivity of product, and easy decomposition of H2O2. To overcome these problems, various effective and feasible strategies are proposed, and the mechanisms, advantages and disadvantages of these strategies are also discussed. Furthermore, the environmental applications of photocatalytic H2O2 evolution are summarized in brief. More significantly, the challenges and future prospects about photocatalytic H2O2 production are proposed. In short, it is expected that this review can share some meaningful insights into photocatalytic H2O2 generation and provide some valuable references for future research.