2D photocatalysts for hydrogen peroxide synthesis

Photocatalytic hydrogen peroxide (H₂O₂) synthesis, driven by solar energy, offers a sustainable and cleaner alternative for producing green H₂O₂ from water and oxygen. 2D photocatalysts have emerged as powerful materials for this purpose due to their unique physiochemical properties such as a flexible planar structure and large surface area. This review provides a comprehensive overview of the latest advances in 2D photocatalytic materials employed in H₂O₂ synthesis, including metal oxides, metal chalcogenides, bismuth-based materials, graphitic carbon nitrides (g-C₃N₄), metal−organic frameworks (MOFs), and covalent organic frameworks (COFs). Beginning with an extensive introduction to possible reaction routes for photocatalytic H₂O₂ synthesis, we summarize the common methods for H₂O₂ detection, crucial for obtaining reliable results in H₂O₂ studies. Additionally, we highlight molecular-level modification strategies for 2D photocatalysts, such as surface modification, ion doping, defect engineering, and heterojunction construction, which promote high-efficiency solar-to-chemical conversion for sustainable H₂O₂ photosynthesis. Furthermore, we discuss key issues and provide perspective outlooks for the efficient and sustainable generation of H₂O₂ in scale-up industrial production. This review offers in-depth insights into different reaction pathways of H₂O₂ synthesis and provides design principles for 2D photocatalysts to enhance H₂O₂ production, guiding the development of efficient photocatalysts for H₂O₂ synthesis.