Strongly Coupled 3D N-Doped MoO2/Ni3S2 Hybrid for High Current Density Hydrogen Evolution Electrocatalysis and Biomass Upgrading

Lin Wang; Junhui Cao; Chaojun Lei; Qizhou Dai; Bin Yang; Zhongjian Li; Xingwang Zhang; Chris Yuan; Lecheng Lei; Yang Hou

doi:10.1021/acsami.9b06502

Strongly Coupled 3D N-Doped MoO₂/Ni₃S₂ Hybrid for High Current Density Hydrogen Evolution Electrocatalysis and Biomass Upgrading

ACS Appl Mater Interfaces. 2019 Aug 7;11(31):27743-27750. doi: 10.1021/acsami.9b06502. Epub 2019 Jul 26.

Authors

Lin Wang^{1

2}, Junhui Cao¹, Chaojun Lei¹, Qizhou Dai², Bin Yang¹, Zhongjian Li¹, Xingwang Zhang¹, Chris Yuan³, Lecheng Lei¹, Yang Hou¹

Affiliations

¹ Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering , Zhejiang University , 38 Zheda Road , Hangzhou , Zhejiang 310027 , China.
² College of Environment , Zhejiang University of Technology , 18 Chaowang Road , Hangzhou , Zhejiang 310014 , China.
³ Department of Mechanical and Aerospace Engineering , Case Western Reserve University , Cleveland , Ohio 44106 , United States.

PMID: 31305069
DOI: 10.1021/acsami.9b06502

Abstract

Developing noble metal-free electrocatalysts toward hydrogen evolution reaction (HER) that can work well at ultrahigh current density are crucial components in renewable energy technologies. Herein, we have reported a strongly coupled 3D hybrid electrocatalyst, which consists of N-doped MoO₂ with Ni₃S₂ grown on Ni foam (N-MoO₂/Ni₃S₂ NF) through an annealing treatment, followed by a thermal ammonia reaction. This N-MoO₂/Ni₃S₂ with a particle size of ∼50 nm was evenly grown on the Ni substrate in this 3D hybrid system. Benefiting from the strong coupling effect, the N-MoO₂/Ni₃S₂ NF exhibited a high HER performance in basic media, with a small value of the Tafel slope (76 mV dec^-1) and a low potential of 517 mV at 1000 mA cm^-2, which was superior to that of Pt/C (631 mV at 1000 mA cm^-2). Experimental results revealed that constructing a coupling interface between N-MoO₂ and Ni₃S₂ facilitated the absorption and dissociation of water molecules, consequently boosting the HER activity. Additionally, the 3D N-MoO₂/Ni₃S₂ NF hybrid could act as a bifunctional electrode for both anode (biomass upgrading) and cathode (HER), which only required a lower potential of 2.08 V at 100 mA cm^-2 as compared to the overall water splitting (2.25 V) and achieved a high biomass conversion ratio of over 90%. Moreover, substituting oxygen evolution reaction by urea oxidation reaction also can assist energy-saving hydrogen evolution for 3D N-MoO₂/Ni₃S₂ NF.

Keywords: 3D N-doped hybrid; biomass upgrading; hydrogen evolution reaction; strong coupling effect; ultra-high current density.