Metal-Free Photocatalysts for Conversion of H O into Hydrogen Peroxide.

Hydrogen peroxide (H O ) is an important green oxidizing agent for environmental protection and chemical production. In comparison to the traditional anthraquinone method, photosynthesis is a green and energy-saving process for H O production. To improve the stability and practical application value of the H O synthesized by photocatalysis, the H O photosynthesis should be conducted in pure water without involving any sacrificial reagents. In this regard, organic semiconducting catalysts pose as a suitable candidate for photocatalytic H O synthesis owing to their metal-free nature to prevent H O decomposition by the metal ions. In this Perspective, the H O photosynthesis history is firstly introduced, followed by a review of the organic semiconductor photocatalysts reported to date. Finally, the main problems to thwart the advances of current pure H O-to-H O photosynthesis are discussed, followed by proposed solutions to address these issues in order to pave new ways for the development of highly efficient metal-free organic photocatalysts for sustainable pure H O-to-H O conversion.