Photocatalytic H₂O₂ production by O₂ reduction is an environmental-friendly process for solar light conversion to chemical energy. In this work, Ti₃C₂ MXene was used as a non-noble metal cocatalyst to load on P25 as Ti₃C₂/TiO₂ (TC/TO) photocatalysts for photocatalytic H₂O₂ synthesis. A H₂O₂ formation rate (179.7 μmol L⁻¹ h⁻¹) of the optimized 10 %-TC/TO composite was obtained to be over 21 folds as high as that of P25 under UV light. Radical quenching experiments and superoxide radical detection confirmed the superoxide radical as the primary intermediate, suggesting the O₂ reduction in two-step single-electron indirect reaction. The higher activity of TC/TO can be attributed to the functions of Ti₃C₂ MXene in accelerating the separation and transfer of photogenerated electron-hole pairs, suppressing their recombination, and blocking the surface TiOOH formation. This work proves the promising roles of Ti₃C₂ MXene in the photocatalytic reaction and further expands their new applications in photocatalysis.

通过O ₂还原产生的光催化H ₂ O ₂是一种将太阳光转换成化学能的环保方法。在这项工作中，Ti ₃ C ₂ MXene被用作非贵金属助催化剂，负载在P25上，作为Ti ₃ C ₂ / TiO ₂（TC / TO）光催化剂用于光催化H ₂ O ₂合成。AH ₂ O ₂形成速率（179.7μmolL ^-1 h ^-1最佳化的10％-TC / TO复合材料的）在紫外光下比P25高21倍。自由基猝灭实验和超氧自由基检测证实了超氧自由基为主要中间体，表明两步单电子间接反应中的O ₂还原。TC / TO的较高活性可归因于Ti ₃ C ₂ MXene在加速光生电子-空穴对的分离和转移，抑制它们的复合并阻止表面Ti OOH形成方面的功能。这项工作证明了Ti ₃ C ₂ MXene在光催化反应中的有前途的作用，并进一步扩展了它们在光催化中的新应用。