Heterostructured CoP·CoMoP nanocages as advanced electrocatalysts for efficient hydrogen evolution over a wide pH range

Tiantian Zhang; Yihui Wang; Junhua Yuan; Keming Fang; Ai-Jun Wang

doi:10.1016/j.jcis.2022.02.005

Heterostructured CoP·CoMoP nanocages as advanced electrocatalysts for efficient hydrogen evolution over a wide pH range

J Colloid Interface Sci. 2022 Jun:615:465-474. doi: 10.1016/j.jcis.2022.02.005. Epub 2022 Feb 4.

Authors

Tiantian Zhang¹, Yihui Wang¹, Junhua Yuan², Keming Fang³, Ai-Jun Wang³

Affiliations

¹ Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Life Sciences and Chemistry, Zhejiang Normal University, Jinhua, Zhejiang 321004, China.
² Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Life Sciences and Chemistry, Zhejiang Normal University, Jinhua, Zhejiang 321004, China; School of Pharmacy, Hubei University of Science and Technology, Xianning, Hubei 437100, China. Electronic address: jhyuan@zjnu.cn.
³ College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, Zhejiang 321004, China.

PMID: 35150954
DOI: 10.1016/j.jcis.2022.02.005

Abstract

A sustainable and environmental-friendly method to produce hydrogen with high purity is the electrochemical water splitting, but its commercialization is challenged due to lack of cost-effective electrocatalysts for hydrogen evolution reaction (HER) over a wide pH range. Herein, a series of CoP·xCoMoP heterostructured nanocages (NCs) were prepared via a dissolution-regrowth and subsequent phosphorization process using metal-organic frameworks (MOFs) as template. The three-dimensional (3D) architecture of CoP·xCoMoP is constituted by the heterostructured nanosheets composed with CoP and CoMoP phase. These noble-metal-free earth-abundant transition metal phosphide (TMP) catalysts show a pH-universal HER activity with high efficiency. Under the optimal atom ratio of Co and Mo (6:5), CoP·5CoMoP NC catalysts can deliver a current density of 10 mA cm^-2 at the overpotential of 72 mV with a Tafel slope of 60.3 mV dec^-1 in 1.0 M KOH solution. The same current output requires overpotential of 44 mV in 0.5 M H₂SO₄ solution and 151 mV in1.0 M phosphate buffered solution (PBS), respectively. The superior HER activity of CoP·5CoMoP NC catalysts can be comparable to or even better than most of noble metal-free HER electrocatalysts reported recently. In addition, CoP·5CoMoP NC catalysts also show a fairly high HER stability over a wide pH range, and their HER activity can be well kept without significant loss for long-term electrolysis. The 3D CoP·5CoMoP heterostructured catalysts hold promise as efficient and low-cost catalysts for water splitting devices over a wide pH range.

Keywords: Heterostructure; Hydrogen evolution reaction; Nanocage; Transition metal phosphides; Water splitting.