Unusual Activity of Rationally Designed Cobalt Phosphide/Oxide Heterostructure Composite for Hydrogen Production in Alkaline Medium

Merfat M Alsabban; Mathan Kumar Eswaran; Karthik Peramaiah; Wandi Wahyudi; Xiulin Yang; Vinoth Ramalingam; Mohamed N Hedhili; Xiaohe Miao; Udo Schwingenschlögl; Lain-Jong Li; Vincent Tung; Kuo-Wei Huang

doi:10.1021/acsnano.1c09254

Unusual Activity of Rationally Designed Cobalt Phosphide/Oxide Heterostructure Composite for Hydrogen Production in Alkaline Medium

ACS Nano. 2022 Mar 22;16(3):3906-3916. doi: 10.1021/acsnano.1c09254. Epub 2022 Mar 7.

Authors

Merfat M Alsabban^{1

2

3}, Mathan Kumar Eswaran¹, Karthik Peramaiah^{1

2}, Wandi Wahyudi¹, Xiulin Yang^{1

2}, Vinoth Ramalingam^{1

2}, Mohamed N Hedhili⁴, Xiaohe Miao⁴, Udo Schwingenschlögl¹, Lain-Jong Li^{1

5}, Vincent Tung^{1

2}, Kuo-Wei Huang^{1

2}

Affiliations

¹ Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
² KAUST Catalysis Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
³ Department of Chemistry, University of Jeddah, Jeddah 21959, Kingdom of Saudi Arabia.
⁴ Core Laboratories, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
⁵ Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.

Abstract

Design and development of an efficient, nonprecious catalyst with structural features and functionality necessary for driving the hydrogen evolution reaction (HER) in an alkaline medium remain a formidable challenge. At the root of the functional limitation is the inability to tune the active catalytic sites while overcoming the poor reaction kinetics observed under basic conditions. Herein, we report a facile approach to enable the selective design of an electrochemically efficient cobalt phosphide oxide composite catalyst on carbon cloth (CoP-Co_xO_y/CC), with good activity and durability toward HER in alkaline medium (η₁₀ = -43 mV). Theoretical studies revealed that the redistribution of electrons at laterally dispersed Co phosphide/oxide interfaces gives rise to a synergistic effect in the heterostructured composite, by which various Co oxide phases initiate the dissociation of the alkaline water molecule. Meanwhile, the highly active CoP further facilitates the adsorption-desorption process of water electrolysis, leading to extremely high HER activity.

Keywords: cobalt mixed oxides; cobalt phosphide; electrochemical catalyst; hydrogen evolution reaction (HER); phosphatization.