The co-catalyst effect of NiSe2 supporter: Boost photocatalytic hydrogen evolution efficiency of TiO2

Abstract

Supporters play an extremely crucial role in the fabrication of highly dispersible catalysts. However, the supporter can only play the role of hosting the main catalyst and does not directly participate in the catalytic reaction as an active site. Herein, the NiSe2 nanoparticles were prepared by a selenide method using NiC2O4 as precursors, and then employed as supporter and cocatlyst to construct NiSe2/TiO2 hybrid by a facile mechanical stirring. The NiSe2/TiO2 hybrid with the optimal ratio of NiSe2 (15 wt%) manifested significantly improved the amount of photocatalytic H2 evolution of nearly 30000 μmol/g, which is 39 times in comparison to pristine TiO2 (756 μmol/g). The mechanism of performance enhancement was fully investigated and supposed that NiSe2 supporter can enhance dispersibility of TiO2, which increased the stacked-type pore size and pore volume by 2.5 and 10 times, respectively. Additionally, NiSe2 can improve the light absorption capacity of the catalyst system and broaden the light absorption range to the visible light region. What’ more, the higher work function of NiSe2 facilitates the formation of electron sink, which leading to the effectively separation of photo-generated carriers. The promising outcomes of this study on NiSe2/TiO2 hybrid highlight the dual role of transition metals as co-catalyst and supporter in catalytic processes, offering valuable insights for further exploration of the co-catalytic capabilities of supporters.