Preparation of C–TiO 2 photocatalyst with Ti 3 C 2 MXene as precursor by molten salt method and its hydrogen production performance

In this paper, Ti 3 C 2 was completely oxidized at a high temperature (350 °C, 400 °C and 450 °C) to form a composite catalysts: TiO 2 nanoparticles with fragmentary carbon supporting, using the ZnCl 2 molten salt method. The generated disordered carbon forms an inseparable connection with TiO 2 nanoparticles grown in situ on the surface, which reduces the recombination of photocarriers and increases the specific surface area. ZnCl 2 plays an important role in delaying the oxidation rate, thus inhibiting the abnormal growth of TiO 2 grain and retaining more carbon, which led to a suitable composition of the catalyst, so as to obtain a better hydrogen production performance. ZnCl 2 existence might also prevent the collapse of the accordion structure during the calcination process. The hydrogen production activity of C–TiO 2 photocatalyst prepared by molten salt method with 3 wt% Pt as cocatalyst is up to 2.3 mmol/g/h, about 5.4 times and 2 times of that of calcination without molten salt and pure P25, respectively. Graphical abstract