Photocatalytic H2O2 production using Ti3C2 MXene as a non-noble metal cocatalyst

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 Ti OOH formation. This work proves the promising roles of Ti3C2 MXene in the photocatalytic reaction and further expands their new applications in photocatalysis.