Ni_(1-x)Co_xSe_2-C/ZnIn_2S_4 Hybrid Nanocages with Strong 2D/2D Hetero-Interface Interaction Enable Efficient H_2-Releasing Photocatalysis

摘要

Designing a semiconductor-based heterostructure photocatalyst for achieving the efficient separation of photogenerated electron-hole pairs is highly important for enhancing H-2 releasing photocatalysis. Here, a new class of Ni1-xCoxSe2-C/ZnIn2S4 hierarchical nanocages with abundant and compact ZnIn2S4 nanosheets/Ni1-xCoxSe2-C nanosheets 2D/2D hetero-interfaces, is designed and synthesized. The constructed heterostructure photocatalyst exposes rich hetero-junctions, supplying the broad and short transfer paths for charge carriers. The close contacts of these two kinds of nanosheets induce a strong interaction between ZnIn2S4 and Ni1-xCoxSe2-C, improving the separation and transfer of photo-generated electron-hole pairs. As a consequence, the distinctive Ni1-xCoxSe2-C/ZnIn2S4 hierarchical nanocages without using additional noble-metal cocatalysts, display remarkable H-2-relaesing photocatalytic activity with a rate of 5.10 mmol g(-1) h(-1) under visible light irradiation, which is 6.2 and 30 times higher than those of fresh ZnIn2S4 nanosheets and bare Ni1-xCoxSe2-C nanocages, respectively. Spectroscopic characterizations and theory calculations reveal that the strong interaction between ZnIn2S4 and Ni1-xCoxSe2-C 2D/2D hetero-interfaces can powerfully promote the separation of photo-generated charge carriers and the electrons transfer from ZnIn2S4 to Ni1-xCoxSe2-C.