Polyoxo-titanium clusters promoted photocatalytic H2 evolution activity in a NiS modified CdS/MIL-101 system

In this work, a new strategy is developed to design and synthesize quaternary catalysts NiS/CdS/MIL-101/PTCs (MIL = Materials of Institute Lavoisier, PTCs = polyoxo-titanium clusters) with excellent photocatalytic activity for H-2 evolution. PTCs and NiS can be successfully integrated into CdS/MIL-101 system by multi-step solvothermal in situ reaction method. The as-synthesized photocatalysts integrated with NiS and PTCs exhibit the dramatically enhanced photocatalytic activity for hydrogen evolution, which is approximately 230 times higher than that of uncoupled catalyst CdS/MIL-101. It is more interesting that the photocatalytic activity can be tuned by structural evolution of PTCs. The photoelectrochemical characteristics of catalysts confirm that the drastic enhancement for photocatalytic H2-production activity was predominantly attributed to PTCs and NiS contributing to matching energy gap and improving visible-light response, respectively, and both inhibiting recombination of photogenerated electron-hole pairs. More importantly, this work can flourish the design idea derived from the relation of structure and application for photocatalysts. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

A new strategy was developed in this work to design and synthesize quaternary catalysts with excellent photocatalytic activity for H2 evolution. The photocatalysts showed significantly enhanced hydrogen production activity, with the possibility of further improvement by tuning the structural evolution of PTCs. The photocatalytic enhancement was attributed to the contributions of PTCs and NiS in matching energy gap, improving visible-light response, and inhibiting recombination of electron-hole pairs.