MoS₂/Graphene Cocatalyst for Efficient Photocatalytic H₂ Evolution under Visible Light Irradiation

Abstract

Exploiting noble-metal-free cocatalysts is of huge interest for photocatalytic water splitting using solar energy. Here we report a composite material consisting of CdS nanocrystals grown on the suface of a nanosized MoS2/graphene hybrid as a high-performance noble-metal-free photocatalyst for H2 evolution under visible light irradiation. Through the optimizing of each component proportion, the MoS2/G-CdS composite showed the highest photocatalytic H2 production activity when the content of the MoS2/graphene cocatalyst is 2.0 wt % and the molar ratio of MoS2 to graphene is 1:2. The photocatalytic H2 evolution activity of the proposed MoS2/G-CdS composite was tested and compared in Na2S-Na2SO3 solution and lactic acid solution. A 1.8 mmol/h H2 evolution rate in lactic acid solution corresponding to an AQE of 28.1% at 420 nm is not only higher than the case in Na2S-Na2SO3 solution of 1.2 mmol/h but also much higher than that of Pt/CdS in lactic acid solution. The relative mechanism has been investigated. It is believed that this kind of MoS2/G-CdS composite would have great potential as a promising photocatalyst with high efficiency and low cost for photocatalytic H2 evolution reaction.

Layer-controlled growth of MoS2 on self-assembled flower-like Bi2S3 for enhanced photocatalysis under visible light irradiation

“…15 As an important non-noble cocatalyst, MoS 2 is a highly promising candidate for photocatalysis and many other applications. [16][17][18][19][20] Thus, using MoS 2 is reasonable for strengthening the visible light photocatalytic performance of Bi 2 S 3 . [21][22][23][24] As a cocatalyst, the morphology and nanostructure of MoS 2 , for example, nanoparticles, 25 nanoclusters, 26 nanospheres 27 and nanosheets, 19,28 have considerable effects on the catalytic performance of MoS 2 -activated hybrids.…”

Ultrahigh, Ultrafast, and Self‐Powered Visible‐Near‐Infrared Optical Position‐Sensitive Detector Based on a CVD‐Prepared Vertically Standing Few‐Layer MoS2/Si Heterojunction

“…To conquer the drawbacks of wavelength and lifetime limitations, van der Waals heterostructures,15 or lateral heterostructures,16, 17 which are made by stacking a monolayer on the top of another monolayer or a few‐layer crystal or controlled by epitaxial growth of lateral heterojunction, are developed and show great potential for designing high‐performance 2D material‐based photodetectors owing to the combined advantages and synergetic effects of different 2D materials with various band gaps and work functions,18, 19, 20 and the ultrafast layer‐to‐layer transfer speed of carriers 21. To date, various van der Waals heterostructures and lateral heterostructures have been prepared and successfully applied in photodetectors,17, 22 field‐effect transistors,23 photocatalysts,24 and solar cells 16, 25. However, large‐area defect‐free monolayer MoS 2 has not yet been widely demonstrated and accurate transfer and positioning cannot be well achieved, making it difficult to utilize for large‐scale and high‐quality device applications as surface effects, such as surface band bending, surface roughness, photodesorption, gas chemisorption, and surface related defects or states, have significantly important effects on the photoelectric properties of 2D materials 26.…”

Biomolecule-assisted synthesis of defect-mediated Cd1−xZnxS/MoS2/graphene hollow spheres for highly efficient hydrogen evolution

“…16 The synergetic effects between MoS 2 and graphene have been well demonstrated by using TiO 2 and CdS as prototypes. 17,18 It has been revealed that the electrocatalytic activity of MoS 2 is derived from the undercoordinated sulfur edge sites, while their basal planes remain inert toward hydrogen evolution. 19 For the MoS 2 decorated photocatalysts, their performance can be influenced by many factors, such as morphology, crystalline phase, electronic structure and defect state.…”