Unique 1D Cd_1−xZn_xS@O‐MoS₂/NiO_x Nanohybrids: Highly Efficient Visible‐Light‐Driven Photocatalytic Hydrogen Evolution via Integrated Structural Regulation

Abstract

Development of noble‐metal‐free photocatalysts for highly efficient sunlight‐driven water splitting is of great interest. Nevertheless, for the photocatalytic H2 evolution reaction (HER), the integrated regulation study on morphology, electronic band structures, and surface active sites of catalyst is still minimal up to now. Herein, well‐defined 1D Cd1−xZnxS@O‐MoS2/NiOx hybrid nanostructures with enhanced activity and stability for photocatalytic HER are prepared. Interestingly, the band alignments, exposure of active sites, and interfacial charge separation of Cd1−xZnxS@O‐MoS2/NiOx are optimized by tuning the Zn‐doping content as well as the growth of defect‐rich O‐MoS2 layer and NiOx nanoparticles, which endow the hybrids with excellent HER performances. Specifically, the visible‐light‐driven (>420 nm) HER activity of Cd1−xZnxS@O‐MoS2/NiOx with 15% Zn‐doping and 0.2 wt% O‐MoS2 (CZ0.15S‐0.2M‐NiOx) in lactic acid solution (66.08 mmol h−1 g−1) is about 25 times that of Pt loaded CZ0.15S, which is further increased to 223.17 mmol h−1 g−1 when using Na2S/Na2SO3 as the sacrificial agent. Meanwhile, in Na2S/Na2SO3 solution, the CZ0.15S‐0.2M‐NiOx sample demonstrates an apparent quantum yield of 64.1% at 420 nm and a good stability for HER under long‐time illumination. The results presented in this work can be valuable inspirations for the exploitation of advanced materials for energy‐related applications.

Defect Engineering of Photocatalysts for Solar Energy Conversion

“…In a heterogeneous PC system, hydrogen and oxygen can be collected simultaneously, presenting the advantage for practical industrial applications. With regard to the modulation of the PC water splitting by defect engineering, Wang et al reported 1D Cd 1− x Zn x S@O‐MoS 2 /NiO x hybrids by the integration of oxygen‐incorporated MoS 2 (O‐MoS 2 ) and NiO x with abundant defects that endowed a remarkable hydrogen evolution rate of 223.17 mmol h −1 g −1 in Na 2 S/Na 2 SO 3 solution as the sacrificial agent and an apparent quantum yield of 64.1% at 420 nm as well as outstanding durability (Figure a,b) . The heterostructures by the integration of WO 3 and V s ‐ZnIn 2 S 4 with NiS quantum dots reached the high PC hydrogen production rate of 11.09 mmol g −1 h −1 under visible‐light irradiation and an apparent quantum efficiency of 72% at 420 nm (Figure c,d) .…”

“…a,b) Energy‐band alignments and schematic illustration of solar water splitting over Cd 1− x Zn x S@O‐MoS 2 /NiO x hybrids. Reproduced with permission . Copyright 2019, Wiley‐VCH.…”

Unique Cd1−xZnxS@WO3−x and Cd1−xZnxS@WO3−x/CoOx/NiOx Z-scheme photocatalysts for efficient visible-light-induced H2 evolution

“…The synthesis of 1D Cd 1−x Zn x S solid solutions was carried out according to the ethanediamine-assisted solvothermal method reported in our recent work [34].…”

“…1. Firstly, the 1D Cd 1−x Zn x S solid solutions with different aspect ratios were prepared by an ethylenediamine-directing solvothermal strategy [34]. Subsequently, the Cd 1−x Zn x S was ultrasonically dispersed in EG solution containing different concentrations of WCl 4 , which was then stirred for 30 min before it was rinsed with ethanol and water and dried in an oven to produce…”

Bifunctional Hydrogen Production and Storage on 0D–1D Heterojunction of Cd0.5Zn0.5S@Halloysites

“…Nevertheless, there is still a series of adverse factors during the photocatalytic reaction process of Cd 1‐ x Zn x S, such as easy agglomeration of Cd 1‐ x Zn x S nanoparticles, the rapid recombination of the electron–hole pairs as well as the serious photocorrosion (i.e., S 2‐ in Cd 1‐ x Zn x S oxidized by photoinduced holes) . To deal with the above‐mentioned problems, various methods have been developed to enhance the photocatalytic activity and photochemical stability, including nano‐/microstructure control, metal or non‐metal elements doping and heterojunction construction, etc . However, the reported routine methods are incapable of solving all the disadvantages in Cd 1‐ x Zn x S in one pot, particularly the photocorrosion.…”