Ti3C2 MXene co-catalyst assembled with mesoporous TiO2 for boosting photocatalytic activity of methyl orange degradation and hydrogen production

Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis. However, the biggest challenge in photocatalysis is the efficient separation of photo-induced carriers. To this end, we report that the mesoporous TiO2 nanoparticles are anchored on highly conductive Ti3C2 MXene co-catalyst by electrostatic self-assembly strategy. The constructed mesoporous TiO2/Ti3C2 composites display that the mesoporous TiO2 nanoparticles are uniformly distributed on the surface of layer structured Ti3C2 nanosheets. More importantly, the as-obtained mesoporous TiO2/Ti3C2 composites reveal the significantly enhanced light absorption performance, photo-induced carriers separation and transfer ability, thus boosting the photocatalytic activity. The photocatalytic methyl orange degradation efficiency of mesoporous TiO2/Ti3C2 composite with an optimized Ti3C2 content (3 wt%) can reach 99.6% within 40 min. The capture experiments of active species confirm that the •O2− and •OH play major role in photocatalytic degradation process. Furthermore, the optimized mesoporous TiO2/Ti3C2 composite also shows an excellent photocatalytic H2 production rate of 218.85 μmol g–1 h–1, resulting in a 5.6 times activity as compared with the pristine mesoporous TiO2 nanoparticles. This study demonstrates that the MXene family materials can be applied as highly efficient noble-metal-free co-catalysts in the field of photocatalysis.