High-performance TiO2 photocatalyst caused by the versatile functions of the tiny bimetallic MOF-derived NiCoS-porous carbon cocatalyst
Only 0.2 at% bimetallic Zeolitic Imidazolate Framework (NiCo-ZIF)-templated NiCoS-porous carbon (PC) exhibited versatile functions on the morphology as well as photocatalytic hydrogen performance of TiO2 nanocrystals, which not only refined the TiO2 particle size during the post annealing process at high temperature, but also transform into high conductive NiCoS-PC cocatalyst. The conductive PC improved the transport of the charge carriers, and increased the exposed active sites by confining the small particle size of TiO2. Furthermore, the well dispersed NiCoS could be regarded as hydrogen production cocatalyst on account of the improved electrochemical hydrogen evolution reaction (HER). Consequently, the optimal TiO2-NiCoS-PC exhibited extremely high photocatalytic hydrogen production rate of 1.29 mmol/h/g, which was 64.5 and 2.4 times in comparison with that of the pristine TiO2 and commercial P25, providing an effective way for development of high-performance MOF templated nanoporous photocatalysts.