Tan Yang,Zhang Zheng,Guo Fuqiang,Guo Renqing,Bai Haineng,Zhang Baohua,Li Xin,Yang Qian,Liu Xuebo
In this study, multi-shaped CdS was synthesized by hydro- and solvothermal methods. Interestingly, the results of scanning electron microscopy and transmission electron microscopy showed that branch-like CdS could be transformed into ball-like and flake-like in deionized water by ethylenediaminetetraacetic acid and l -cysteine, respectively, and the growth mechanism of CdS was discussed and explored: the ion-binding rate might be the main factor for the morphology transformation of CdS. X-ray diffraction and energy dispersive spectroscopy revealed branch-like CdS which exhibited the hexagonal phase. Besides, the optical characteristics of CdS were performed by ultraviolet–visible and photoluminescence spectrum. Also, CdS was utilized to explore the photocatalytic activity of rhodamine B, and the result showed that the photocatalytic activity of ball-like CdS was higher than flake-like and branch-like CdS.
Ruiding Fei,Jianfeng Zhao,Huinan Wang,Huijuan Lin,Kui Xu,Guang Zeng,Wenchao Wang,Zhiping Yan
The hydrogen evolution capacity of MoS2 is impeded by its intrinsically highly electronegative sulfur sites, which firmly bind absorbed atomic H through S–Hads bonds and subsequently diminish H2 release. Designing effective surface-active sites to optimize atomic hydrogen activation and desorption for the hydrogen evolution reaction (HER) in water, while also expanding near-infrared (NIR) light responsiveness, remains a significant challenge. We have developed complexes of sulfur vacancy (Sv) enriched CdSv capped with W-modified MoS2+x (MoWS2+x) through an in situ substitution approach, followed by a photoreduction reaction. The bimetallic MoWS2+x cocatalyst not only increases the density of unsaturated coordinating S active sites but also attenuates the strength of the S–Hads bond. The optimized MoWS2+x/CdSv hybrid shows synergistic improvement of atomic H activation and desorption for the solar-driven HER, achieving the highest recorded H2-evolution rate of 9166.13 μmol g−1 h−1 under visible light (λ ≥ 420 nm), which marks a substantial improvement (greater than 750%), and an apparent quantum yield of 19.13%. Remarkably, the target photocatalyst, which is abundant in sulfur vacancies within its CdSv component, also achieves H2 production driven by NIR light beyond 780 nm, with a H2 evolution rate of 1326.82 μmol g−1 h−1. Comprehensive experimental and theoretical investigations corroborate that the existence of unsaturated coordinated S sites mitigates the strength of S–Hads bonds, resulting in the high driving force of H2 bubble release from water and long-lived active charge carriers. In this paper, we constructed visible light and NIR-active photocatalysts successfully for hydrogen production, highlighting the synergetic effects within this unique system. Additionally, the photo-behaviors of charge carriers have been investigated by ultra-fast spectroscopic techniques to gain a deeper understanding of the interfacial charge transfer kinetics. This study provides valuable insights into the development and optimization of photocatalysts that are responsive to both NIR and visible light, paving the way for more efficient solar-driven applications.
危险品化学品经营许可证（带存储）