Dual-Modified Cu2S with MoS2 and Reduced Graphene Oxides as Efficient Photocatalysts for H2 Evolution Reaction

Enna Ha,Zongyuan Xin,Luyang Wang,Danyang Li,Jingge Zhang,Xin Hu,Tao Ji,Junqing Hu

doi:10.3390/catal11111278

Abstract

Noble metal-free cocatalysts have drawn great interest in accelerating the catalytic reactions of metal chalcogenide semiconductor photocatalyst. In particular, great efforts have been made on modifying a semiconductor with dual cocatalysts, which show synergistic effect of a fast transfer of exciton and energy simultaneously. Herein, we report the dual-modified Cu2S with MoS2 and reduced graphene oxides (Cu2S-MoS2/rGO). The in situ growth of Cu2S nanoparticles in the presence of MoS2/rGO resulted in high density of nanoscale interfacial contacts among Cu2S nanoparticles, MoS2, and rGO, which is beneficial for reducing the photogenerated electrons’ and holes’ recombination. The Cu2S-MoS2/rGO system also demonstrated stable photocatalytic activity for H2 evolution reaction for the long term.

Highlights

Chalcocite copper(I) sulfide (Cu2S) is a typical p-type semiconductor with a bulk band gap of 1.2 eV [1], which has been extensively studied and used in many applications, such as cancer therapy [2,3], batteries [4], solar cell [5], catalyst [6], etc
The conduction band (CB) of Cu2S is more negative than the proton reduction potential, and the narrow band gap enables the absorption of solar energy in the visible regime [17]
The crystalline structure of the nanostructures was characterized by powder X-ray diffraction (PXRD), which was performed on a SmartLab® X-ray diffractometer (Rigaku, Tokyo, Japan) at room temperature with Cu Kα radiation (λ = 1.5418 Å) and a diffraction angle 2θ ranging from 5◦ to 90◦

Summary

Introduction

Chalcocite copper(I) sulfide (Cu2S) is a typical p-type semiconductor with a bulk band gap of 1.2 eV [1], which has been extensively studied and used in many applications, such as cancer therapy [2,3], batteries [4], solar cell [5], catalyst [6], etc. Much effort has been made to synthesize the Cu2S of various nanostructures, a systematic study on the morphology–performance relationship and the suppression of photoelectron recombination remain the key challenges to improve their photocatalytic performances. Formation of heterogeneous structures is a key approach for improving the activity of photocatalysts by suppressing the recombination probability of photoexcited electron-hole pairs [18,19]. The high cost and low availability of noble metals limit their industrial application. WseynatlhsoessizyesdtemthaetCicual2lSy-MinovSe2s/rtGigOatecdomthpeomsitoerspthhorolouggyh eaffseicmtspolenwpehtoctohceamtaisltyrtyicaHppErRoapcehr.formshW foaornewmcaeealdsnoocfthesCeyuosh2tfieSgmChnaeuatsn2itScoapslhntlyraounticonotcvsuaterrtseuatslicy.gtutTaitrcheeedhs.ystpdhThrehoemegrieocsnarpplphhCreoourldi2ocuSagclyntiaeConfnufoe2rpcSatastrentoaiwncnlieoptshphaaoerntxtociccchelaloetlsareelnydattnilococnhnHogMEr-etRoedSrpm2e/ornrp-GhOotoMstoaSb2i/lriGtyO, wshhiocwhesdurtphaeshseigshtehsotspehooftmocaantaylyntoicblheymdreotgael-nmpordoidfiuecdtisoenmriactoenwduitchtoerxscreellpeonrtted inlotnhge-tleitremraptuhroet.ostability, which surpasses those of many noble metal-modified semiconductors reported in the literature

Results and Discussion

Comparative Photocatalyst

Characterization and Photocatalytic Test

Conclusions