Xin Zhang,Haohuan Yuan,Jiao Bao,Wenting Xiao,Guannan He
ZnCdS, a metal chalcogenide solid solution, has attracted significant attention. However, two primary challenges hinder its widespread application in photocatalytic hydrogen evolution : the rapid recombination rate of photogenerated carriers and susceptibility to photo-oxidation in the aqueous environments. In this article, a facile hydrothermal route was employed for the first time to uniformly assemble SnS 2 nanoparticles onto the surface of Zn 0.2 Cd 0.8 S (ZCS) nanopolyhedra. The intimate contact of two materials resulted in the formation of heterojunctions . By adjusting the content of SnS 2 , the hydrogen evolution reaction (HER) performance was optimized to reach up to 12170 μmol/gh, which is 1.9 times of the pristine ZCS. Notably, the photocatalyst demonstrated remarkable stability with an apparent quantum yield (AQY) of 15.5% at 420 nm. The enhanced photocatalytic performance can be attributed to the following factors: (i) The heterojunction composite, with larger surface area and more micropores, provides additional active sites and exhibits high photocatalytic activity ; (ii) The internal electric field accelerates the separation of photogenerated carriers and reduces the recombination rate of electron-hole pairs; (iii) The photogenerated holes can be quickly transferred to the valence band of SnS 2 and react with triethanolamine , thereby significantly reducing the photo-oxidation of ZCS. This work not only proposed a feasible route to improve the photocatalytic activity of ZCS, but also provided insights into the role of heterojunctions and the reaction mechanism.
Xiaoming Liu,Yinchu Zhang,Hongwei Wang,Jiajun Yan,Liushui Yan,Kexin Li,Huiqin Guo,Wang Gong,Jun Lin
In this work, a series of Zn x Cd 1-x S solid solutions are firstly prepared by a solvothermal process. The optimized composition of Zn x Cd 1-x S solid solution is determined to be Zn 0·2 Cd 0.8 S. On this basis, the Cu 7 S 4 /Zn 0·2 Cd 0·8 S composite photocatalyst with a binary p-n heterojunction has been synthesized by a co-precipitation process followed by a solvothermal method . Owning to the synergistic effect of the heterojunction structure in the interface of Cu 7 S 4 (p-type) and Zn 0·2 Cd 0·8 S (n-type) and the built-in electric field in binary p-n heterojunction, the as-prepared Cu 7 S 4 /Zn 0·2 Cd 0·8 S composite photocatalyst exhibits a significantly improved photocatalytic activity toward hydrogen production from water with visible light response, which is approximately 5.0 times and 16.5 times higher than of pristine Zn 0·2 Cd 0·8 S and CdS, respectively. The possible photocatalytic mechanism has been proposed basing on a series of experimental results. The current work might be valuable inspirations for designing highly efficient heterojunction composite photocatalyst for solar hydrogen evolution .
This photocatalyst was prepared using an ultrasonic-assisted hydrothermal method regulated by iodide ions. • The resultant Zn 0.2 Cd 0.8 S/TP-PCN exhibits a flake-like structure enveloping the nanospheres. • The Zn 0.2 Cd 0.8 S/TP-PCN exhibited an excellent H 2 evolution rate of 2.83 mmol g −1 h −1 in alkaline PET solution. • Photoreduction mechanism of Zn 0.2 Cd 0.8 S/TP-PCN is proposed and analyzed. Zn 0.2 Cd 0.8 S/TP-PCN nanocomposite photocatalysts were prepared via an ultrasound-assisted hydrothermal method regulated by iodide ions. The resulting composite features intimate interfacial contact and strong electronic coupling, generating a built-in electric field that promotes efficient charge separation and directional transfer while suppressing the photocorrosion of Zn 0.2 Cd 0.8 S. As a result, this composite exhibits an excellent hydrogen evolution rate of 2.83 mmol g −1 h −1 in an alkaline PET solution, which is approximately 4.7 times that of pure TP-PCN. Liquid-state NMR analysis confirms that PET is effectively degraded into small organic molecules such as methanol and formate, demonstrating efficient PET upcycling coupled with hydrogen production. Mechanistic investigations demonstrate that the reaction proceeds via a direct hole-driven oxidation pathway coupled with electron-mediated hydrogen evolution, consistent with a Z-scheme charge transfer mechanism. This work provides a promising strategy for coupling plastic waste upcycling with sustainable hydrogen production, offering new insights into addressing both environmental and energy challenges. Download: Download high-res image (345KB) Download: Download full-size image
Wei Chen,Ting Huang,Tian-Yu Liu,Guo-Rong Duan,Xu-Jie Yang,Xiao-Heng Liu
Highly-efficient visible light driven Zn 0.2 Cd 0.8 S/P-C 3 N 4 heterostructure were successfully synthesized via ultrasound-assisted growth route. The as-prepared Zn 0.2 Cd 0.8 S/P-C 3 N 4 nanocomposites consist of mesoporous P-C 3 N 4 nanosheets immobilized with homogeneously dispersed Zn 0.2 Cd 0.8 S NPs. The photocatalytic applications including photoreduction of 4-nitroaniline (4-NA) and water splitting were employed to evaluate their photocatalytic activities of prepared samples. The intimate interfacial contact between the Zn 0.2 Cd 0.8 S nanoparticles and the P-C 3 N 4 nanosheets endows these nanocomposite photocatalysts with superior visible light photocatalytic activity for both the 4-NA reduction and water splitting in comparison with pure Zn 0.2 Cd 0.8 S NPs and bare P-C 3 N 4 NSs, especially Zn 0.2 Cd 0.8 S/P-C 3 N 4 -80. In addition, we found that Zn 0.2 Cd 0.8 S/P-C 3 N 4 -80 sample possesses excellent stability towards selective reduction of 4-NA to 4-phenylenediamine (4-PDA) during the photocatalytic running experiments. We hope that our current research on the facile fabrication and applications of Zn 0.2 Cd 0.8 S/P-C 3 N 4 samples can provide some new insights in the design, synthesis and application of P-C 3 N 4 based nanocomposites.
危险品化学品经营许可证（带存储）