Lewis acid molten salts prepared Ti₃C₂Cl₂ MXenes assembling with g-C₃N₄ nanosheets for enhanced photocatalytic H₂ evolution

Photocatalytic hydrogen (H₂) evolution is expected to be a promising approach to generating a clean energy source (H₂) with low carbon emissions, which is vital to solving environmental degradation and energy shortages. The critical challenge to designing highly efficient photocatalysts is the fast recombination of photo-generated carriers; thus, we select Ti₃C₂Cl₂ MXene with excellent metal characteristics to serve as a co-catalyst and combine with g-C₃N₄. The Ti₃C₂Cl₂/g-C₃N₄ composites exhibit an enhanced photocatalytic hydrogen evolution activity (maximum 155.9 μmol h⁻¹) while they hardly perform photocatalytic activities. The photoluminescence (PL) spectra shows that Ti₃C₂Cl₂ MXenes help boost the separation of photo-generated carriers of g-C₃N₄ and finally strengthen the photocatalytic hydrogen evolution performance. The ultraviolet–visible (UV–vis) spectra illustrate that composites perform a strengthened light absorption, which fits well with the results in the hydrogen evolution experiment. Thus, we fabricated a highly efficient photocatalyst through a safer molten salt approach without hydrofluoric acid (HF). We believe this work will offer a safer approach to manufacturing catalysts decorated with MXenes for highly efficient photocatalytic H₂ evolution.