CdS nanodots adorned (020)-featured WO3·H2O nanoplates heterojunction with augmented photocatalytic hydrogen production under Z-scheme charge transfer mechanism. Issue 3 (June 2022)

• Record Type: Journal Article
• Authors: Zhao, Longfei; Chen, Xin; Zhang, Yuan; Ye, Zhupeng; Zeng, Yanwei
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 3(2022)
• Publication Date: 2022-06
• Subjects: CdS-WO3·H2O heterojunction -- Interfacial contact -- Hydrogen production -- Z-scheme mechanism; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.107672
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: In this paper, controllable nucleation and growth of CdS nanodots on the (020)-featured WO3 ·H2 O nanoplates has been successfully accomplished to prepare CdS-WO3 ·H2 O heterojunction with high-quality interfacial contact through a slow release of Cd 2+ and S 2- from the gradual self-loop hydrolysis of cadmium acetate and thioacetamide. The chemical and structural characteristics of as-prepared samples before and after heat treatment are detailedly investigated by TG-DSC, XRD, Raman, XPS, FESEM and HRTEM, as well as their light absorption performance from UV-Vis DRS. The maximum average hydrogen production rate for CdS-WO3 ·H2 O reaches 2.15 mmol·g −1 ·h −1 under 300 W Xe lamp irradiation (λ > 420 nm) using lactic acid as sacrificial reagent, which is 8.27 and 2.72 times as much as CdS and CdS-WO3, respectively. According to band alignment, CdS-WO3 ·H2 O exhibits greater energy difference of Fermi level than CdS-WO3, and augmented photocatalytic performance should arise from efficient Z-scheme charge transfer mechanism under stronger built-in electric field, in which the conduction band electrons of WO3 ·H2 O and valence band holes of CdS are expected to effectively recombine at their interfacial zones, while the conduction band electrons of CdS and valence band holes of WO3 ·H2 O contribute to the reduction of H + and oxidation of lactic acid. Graphical Abstract: ga1 Highlights: Controllable nucleation and growth of CdS on (020)-featured WO3 ·H2 O is achieved. High-quality interfacial contact between CdS and WO3 ·H2 O has been constructed. The max average H2 production rate of 2.15 mmol·g −1 ·h −1 is 8.27 times that of CdS. Efficient Z-scheme mechanism results in augmented photocatalytic performance.