Highly Efficient Photocatalytic H₂O₂ Production under Ambient Conditions via Defective In₂S₃ Nanosheets

Oxygen and water generating hydrogen peroxide (H₂O₂) by optical drive is an extremely promising pathway, and the large amount of oxygen in air and natural sunlight illumination are excellent catalytic conditions. However, the separation efficiency of photogenerated electron-hole pairs greatly limits the photocatalytic efficiency, especially in the absence of sacrificial agents. Here, we report an In₂S₃ nanosheet with an S vacancy (S_v-In₂S₃). The highest H₂O₂ yield of S_v-In₂S₃ is 2.585 mmol g^-1 h^-1 under pure water, air, and sunlight (P = 920 W/m²), largely outperforming other reported photocatalysts for H₂O₂ production. The experimental results show that the introduction of S_v accelerates the separation of photogenerated electron-hole pairs and achieves efficient H₂O₂ production through an oxygen reduction reaction. This efficient photosynthesis under ambient conditions allows solar-chemical conversion to take place in a truly cost-effective and sustainable way, opening up possibilities for practical production.