Stoichiometry design in hierarchical CoNiFe phosphide for highly efficient water oxidation

• Published in: Science China materials 2022, Vol.65 (10), p.2685-2693
• Main Authors: Chen, Jiangbo, Ying, Jie, Xiao, Yuxuan, Dong, Yuan, Ozoemena, Kenneth I., Lenaerts, Silvia, Yang, Xiaoyu
• Format: Article
• Language: English
• Subjects: Catalytic activity; Chemistry and Materials Science; Chemistry/Food Science; Composition; Density functional theory; Electrocatalysts; Materials Science; Oxidation; Oxygen evolution reactions; Phosphides; Stability tests; Stoichiometry; Surface reactions
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-022-2061-x

Rational composition design of trimetallic phosphide catalysts is of significant importance for enhanced surface reaction and efficient catalytic performance. Herein, hierarchical Co x Ni y Fe z P with precise control of stoichiometric metallic elements ( x:y:z = (1–10):(1–10):1) has been synthesized, and Co 1.3 Ni 0.5 Fe 0.2 P, as the most optimal composition, exhibits remarkable catalytic activity ( η = 320 mV at 10 mA cm −2 ) and long-term stability (ignorable decrease after 10 h continuous test at the current density of 10 mA cm −2 ) toward oxygen evolution reaction (OER). It is found that the surface P in Co 1.3 Ni 0.5 Fe 0.2 P was replaced by O under the OER process. The density function theory calculations before and after long-term stability tests suggest the clear increasing of the density of states near the Fermi level of Co 1.3 Ni 0.5 Fe 0.2 P/Co 1.3 Ni 0.5 Fe 0.2 O, which could enhance the OH − adsorption of our electrocatalysts and the corresponding OER performance.