Photodeposition of CoOx and MoS2 on CdS as dual cocatalysts for photocatalytic H2 production. (10th October 2022)

• Record Type: Journal Article
• Authors: Di, Tingmin; Deng, Quanrong; Wang, Geming; Wang, Shenggao; Wang, Linxi; Ma, Yuhua
• Is Part Of: Journal of materials science & technology. Volume 124(2022)
• Page Start: 209
• Page End: 216
• Publication Date: 2022-10-10
• Subjects: Photocatalytic H2 production -- CdS -- Dual cocatalysts -- MoS2 -- CoOx -- Photodeposition; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2021.12.071
• Languages: English
• ISSNs: 1005-0302

Abstract

Highlights: Noble-metal-free CoO x and MoS2 are applied as dual cocatalysts for CdS. A two-step photodeposition strategy was used to deposit CoO x and MoS2 on CdS. In a photocatalytic process, MoS2 and CoO x extract electrons and holes, respectively. The synergistic effect between CoO x and MoS2 obviously prolongs the lifetime of photoexcited charge carriers. CoO x and MoS2 significantly improve the H2 -evolution activity of CdS by decreasing the charge recombination rates. Abstract: Photocatalytic H2 production from water splitting has a promising prospect for alleviating energy and environmental issues. However, the fast recombination of photogenerated charge carriers limits the photocatalytic efficiency and its practical application. Cocatalyst engineering is an effective strategy to spatially separate photogenerated charge carriers. In this work, noble-metal-free MoS2 and CoO x cocatalysts are loaded on CdS nanorods by a two-step photodeposition method. The MoS2 functions as the reduction cocatalyst to trap electrons and CoO x as the oxidation cocatalyst to trap holes. Transmission electron microscopy (TEM), inductively coupled plasma (ICP), X-ray photoelectron spectroscopy (XPS) and Mott-Schottky results demonstrate the effectiveness of photodeposition for loading MoS2 and CoO x dual cocatalysts on CdS and their impact on the photochemical properties. The optimized CdS-MoS2 -CoO x composite exhibits a high photocatalytic H2 -production rate of 7.4 mmol g –1 h –1 and an apparent quantum efficiency (QE) of 7.6% at 420 nm. Further analysis on time-resolved photoluminescence (TRPL) indicates that the introduction of dual cocatalysts greatly prolongs the lifetime of photogenerated charge carriers and deceases the charge recombination rates, consequently leading to superior photocatalytic H2 -production performance. This work provides a facile and effective strategy for the construction of highly efficient dual-cocatalyst-modified CdS photocatalyst for high-performance photocatalytic H2 production.