Cu2ZnSnS4/MoS2-Reduced Graphene Oxide Heterostructure: Nanoscale Interfacial Contact and Enhanced Photocatalytic Hydrogen Generation

Abstract

Hydrogen generation from water using noble metal-free photocatalysts presents a promising platform for renewable and sustainable energy. Copper-based chalcogenides of earth-abundant elements, especially Cu2ZnSnS4 (CZTS), have recently arisen as a low-cost and environment-friendly material for photovoltaics and photocatalysis. Herein, we report a new heterostructure consisting of CZTS nanoparticles anchored onto a MoS2-reduced graphene oxide (rGO) hybrid. Using a facile two-step method, CZTS nanoparticles were in situ grown on the surface of MoS2-rGO hybrid, which generated high density of nanoscale interfacial contact between CZTS and MoS2-rGO hybrid. The photoexcited electrons of CZTS can be readily transported to MoS2 through rGO backbone, reducing the electron-hole pair recombination. In photocatalytic hydrogen generation under visible light irradiation, the presence of MoS2-rGO hybrids enhanced the hydrogen production rate of CZTS by 320%, which can be attributed to the synergetic effect of increased charge separation by rGO and more catalytically active sites from MoS2. Furthermore, this CZTS/MoS2-rGO heterostructure showed much higher photocatalytic activity than both Au and Pt nanoparticle-decorated CZTS (Au/CZTS and Pt/CZTS) photocatalysts, indicating the MoS2-rGO hybrid is a better co-catalyst for photocatalytic hydrogen generation than the precious metal. The CZTS/MoS2-rGO system also demonstrated stable photocatalytic activity for a continuous 20 h reaction.

One‐Step Synthesis of Nb2O5/C/Nb2C (MXene) Composites and Their Use as Photocatalysts for Hydrogen Evolution

“…The Db and demonstrates defects and partially disordered structures of sp 3 -hybridized carbon atoms, whereas the Gband is related to the in-plane vibrationm ode of the sp 2 -hybridized carbon atoms. [40,41] Specific surface area and pore-structure analysis Pristine Nb 2 CT x ,N b 2 O 5 ,o xidized Nb 2 CT x ,a nd Mix-NN were subjected to nitrogen physisorption analysis to evaluate their surface areas, pore volumes, and pore diameters. The nitrogen adsorption/desorptioni sotherms and BJH pore-diameter distribution plots of Nb 2 CT x ,N CN-0.5, NCN-1.0, NCN-1.5, Nb 2 O 5 ,a nd Mix-NN are shown in Figure 2, and the textural properties are listed in Ta ble 1.…”

High photoelectrochemical performance of a p‐type reduced grapheneoxide‐copperoxide/Cu foil (rGO‐CuO/Cu) photoelectrode prepared by a one‐pot hydrothermal method

“…Compared with the results of previous research, a longer reaction time is required to produce a composite structure; in this research, in as little as 3 hours, we manage to prepare the samples accordingly. 33,34 This outcome shows that the existence of rGO definitely impacts the morphology of the sample, which constantly coated by the rGO sheets, that is, the shape changes from a wire to a cubic shape and from layers to flakes with increasing reaction time. The introduction of Cu foil as an electrical collector may increase the number of charged species; in this case, rGO is uniformly layered on the Cu surface, providing an enormous surface zone for photoelectrochemical activity.…”

Microwave-Assisted Solvothermal Synthesis of Chalcogenide Composite Photocatalyst and Its Photocatalytic CO2 Reduction Activity under Simulated Solar Light

“…Therefore, the best strategy to enhance the light harvesting is to create such a photocatalyst, which has not only a narrow band gap, but also the efficient separation of eand h + pairs in the photocatalytic system. In addition, a quaternary copper-based chalcogenide performed efficient capture and utilization of solar energy [7][8][9]. Meanwhile, heterostructured photocatalysts possess a synergic effect to augment the photocatalytic activity [10,11].…”

“…Meanwhile, heterostructured photocatalysts possess a synergic effect to augment the photocatalytic activity [10,11]. MoS 2 /graphene has been reported to have unique properties, such as large surface area, superior electron mobility, and excellent catalytic ability [7]. According to the references, many scientists have synthesized new heterostructured photocatalysts for exploring pronounced enhancements in photocatalytic performance [7][8][9][10][11][12].…”