Green Synthesis of Feather-Shaped MoS₂/CdS Photocatalyst for Effective Hydrogen Production

Abstract

MoS2/CdS photocatalyst was fabricated by a hydrothermal method for H2production under visible light. This method used low toxic thiourea as a sulfur source and was carried out at 200°C. Thus, it was better than the traditional methods, which are based on an annealing process at relatively high temperature (above 400°C) using toxic H2S as reducing agent. Scanning electron microscopy and transmission electron microscopy images showed that the morphologies of MoS2/CdS samples were feather shaped and MoS2layer was on the surface of CdS. The X-ray photoelectron spectroscopy testified that the sample was composed of stoichiometric MoS2and CdS. The UV-vis diffuse reflectance spectra displayed that the loading of MoS2can enhance the optical absorption of MoS2/CdS. The photocatalytic activity of MoS2/CdS was evaluated by producing hydrogen. The hydrogen production rate on MoS2/CdS reached 192 μmol·h−1. This performance was stable during three repeated photocatalytic processes.

MoS2 as a co‐catalyst for photocatalytic hydrogen production from water

“… Impregnation method is widely used for the dispersion of nanoparticulate MoS 2 (2H) on photosensitizer (e.g., CdS, TiO 2 ) for both powdered photocatalysis and PEC processes. For example, MoS 2 on CdS can be prepared by impregnating CdS with an aqueous solution of (NH 4 ) 2 MoS 4 , followed by treatment in H 2 S flow at high temperature . Hydrothermal method could use low toxic thiourea as a sulfur source to react with molybdenum salt (such as Na 2 MoO 4 ), together with semiconductor powders . Ball‐milling method was employed to mix (NH 4 ) 2 MoS 4 and semiconductor powder in the presence of ethanol, followed by high temperature calcination in inert atmosphere . Photodeposition approach could be used to decorate MoS 2 nanocrystals on TiO 2 under UV irradiation with (NH 4 ) 2 MoS 4 as precursor in ethanol/water solution . Anion exchange reaction was applied to synthesize MoS 2 nanotube photoelectrode from Mo 3 O 10 (C 2 H 10 N 2 ) nanowires and l ‐cysteine by heating at 200°C for 14 h . Chemical exfoliation process was usually exploited to prepare 1T metallic MoS 2 catalysts by ion intercalation . …”

“…A green hydrothermal method was explored for the synthesis of MoS 2 /CdS photocatalysts for H 2 production under visible light irradiation . This approach, which uses low toxic thiourea as a sulfur source to react with Na 2 MoO 4 at 200°C, is better than traditional methods, which are based on an annealing process at relatively high temperature (above 400°C) with toxic H 2 S as a reducing agent.…”

Surface Decorated Zn0.15Cd0.85S Nanoflowers with P25 for Enhanced Visible Light Driven Photocatalytic Degradation of Rh-B and Stability

“…The absorption capability in the visible light range of the Zn 0.15 Cd 0.85 S nanoflowers is enhanced as compared to pure CdS and there is an obvious absorption edge shift to 557 nm, which corresponds to a band gap of 2.23 eV, that may be due to the charge transfer between CdS valence band and Zn-3d doping level [32]. All of P25/Zn 0.15 Cd 0.85 S nanocomposite with various P25 contents could absorb light in visible light region, which may be due to the charge transfer between CdS and TiO 2 conduction bands [33]. XPS technique is used to investigate the chemical states of the pure CdS nanoparticles and P25/Zn0.15Cd0.85S nanocomposite (Figure 4).…”

Surface Properties and Photocatalytic Activity of KTaO3, CdS, MoS2 Semiconductors and Their Binary and Ternary Semiconductor Composites

“…[34]. There were few studies on the MoS 2 -CdS system obtained by impregnation [35], ball-milling combined calcination [36], electrodeposition and chemical bath deposition [37] orhydrothermal [38] methods for hydrogen production under visible light. Zong et al showed that individual CdS and MoS 2 particles were almost inactive in hydrogen evolution compared to the MoS 2 particles deposited onto CdS.…”