Constructing direct Z-scheme photocatalysts with black N–TiO2-x/C and Cd0.5Zn0.5S for efficient H2 production

Black N doped TiO2-x nanoparticles loaded on the carbon framework (N–TiO2-x/C, NTC) were successfully fabricated by sol-gel method. In this work, the synthesized NTC material was combined with Cd0.5Zn0.5S (ZCS) short nanorods, forming a direct Z-scheme NTC/ZCS photocatalyst without using of electron mediator. The free radicals trapping experiment was also conducted through the degradation of RhB to determine photocatalytic mechanism. As a result, the 2% NTC/ZCS exhibited an optimal photocatalytic H2 production rate which is up to 36.6 mmol/h/g and about 5.2 times higher than that of pristine ZCS nanorods. The apparent quantum efficiency (AQE) of the 2% NTC/ZCS hybrids at wavelength 420 nm was calculated to 51.2%. Moreover, long-term drying increases the close contact between NTC and ZCS, and this firm contact interface can promote charge transfer and improve photocatalytic stability of NTC/ZCS composite.