Enhancement of photocatalytic H2 evolution over TiO2 nano-sheet films by surface loading NiS nanoparticles

NiS/TiO2 nano-sheet films (NiS/TiO2 NSFs) photocatalysts were prepared by loading NiS nanoparticles as noble metal-free cocatalysts on the surface of TiO2 films through a solvothermal method. The prepared samples were characterized by XRD, SEM, EDS, UV-Vis absorption spectra and XPS analysis. The photocatalytic H-2 evolution and photoluminescence spectroscopy (PL) experiments indicated that the NiS cocatalysts could efficiently promote the separation of photogenerated charge carriers in TiO2 and consequently enhance the H-2 evolution activity. The hydrogen yield obtained from the optimal sample reached 4.31 mu mol cm(-2) at 3.0 h and the corresponding energy efficiency was about 0.26%, which was 21 times higher than that of pure TiO2 NSF. A possible photocatalytic mechanism of NiS cocatalyst on the improvement of the photocatalytic performance of TiO2 NSF was also proposed.