Nitrogen-Doped Oxygenated Molybdenum Phosphide as an Efficient Electrocatalyst for Hydrogen Evolution in Alkaline Media

Muhammad Waqas Khan; Suraj Loomba; Rashad Ali; Md Mohiuddin; Ahmed Alluqmani; Farjana Haque; Yongkun Liu; Rizwan Ur Rehman Sagar; Ali Zavabeti; Turki Alkathiri; Babar Shabbir; Xian Jian; Jian Zhen Ou; Asif Mahmood; Nasir Mahmood

doi:10.3389/fchem.2020.00733

Nitrogen-Doped Oxygenated Molybdenum Phosphide as an Efficient Electrocatalyst for Hydrogen Evolution in Alkaline Media

Front Chem. 2020 Aug 28:8:733. doi: 10.3389/fchem.2020.00733. eCollection 2020.

Authors

Muhammad Waqas Khan^{1

2}, Suraj Loomba¹, Rashad Ali³, Md Mohiuddin¹, Ahmed Alluqmani¹, Farjana Haque¹, Yongkun Liu⁴, Rizwan Ur Rehman Sagar⁵, Ali Zavabeti^{1

6}, Turki Alkathiri^{1

7}, Babar Shabbir⁸, Xian Jian^{3

9}, Jian Zhen Ou¹, Asif Mahmood¹⁰, Nasir Mahmood¹

Affiliations

¹ School of Engineering, RMIT University, Melbourne, VIC, Australia.
² Applied Porous Materials Unit, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, VIC, Australia.
³ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu, China.
⁴ College of Textile Science and Engineering (International Institute of Silk), Zhejiang Sci-Tech University, Hangzhou, China.
⁵ School of Materials Science and Engineering, Jiangxi University of Science and Technology, Ganzhou, China.
⁶ Department of Chemical Engineering, The University of Melbourne, Parkville, VIC, Australia.
⁷ School of Engineering, Albaha University, Al Bahah, Saudi Arabia.
⁸ Department of Materials Science and Engineering, ARC Centre of Excellence in Exciton Science, Monash University, Clayton, VIC, Australia.
⁹ National Engineering Researching Centre of Electromagnetic Radiation Control Materials, State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, China.
¹⁰ School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW, Australia.

Abstract

Phosphides of transition metals (TMPs) are a developing class of materials for hydrogen evolution reaction (HER) as an alternative to expensive noble metals to produce clean energy. Herein, the nitrogen-doped molybdenum oxide (MoO_x) is developed via a facile and simple hydrothermal method, followed by annealing in the N₂ atmosphere and phosphorization to form a nitrogen-doped oxygenated molybdenum phosphide (N-MoP) sphere-shaped structure. The developed N-doped phosphide structure depicts enhanced HER activity by reaching a current density of 10 mA cm^-2 at a very low overpotential of only 87 mV, which is much better than annealed nitrogen-doped molybdenum oxide (A-MoO_x) 138 mV in alkaline medium. N-MoP is a highly efficient electrocatalyst for HER attributed to a more exposed surface, large electrode/electrolyte interface and appropriate binding energies for reactants. This study extends the opportunity of developing nitrogen-doped TMPs, which can display exceptional properties as compared to their oxides.

Keywords: alkaline electrolyte; catalysts; hydrogen evolution reaction; molybdenum phosphide; water-splitting.