Synergistic engineering of P, N-codoped carbon-confined bimetallic cobalt/nickel phosphides with tailored electronic structures for boosting urea electro-oxidation

Ying Wu; Jingfei Kang; Houde Liao; Sha Chen; Jiahao Pi; Jianjie Cao; Yan Qing; Han Xu; Yiqiang Wu

doi:10.1016/j.jcis.2023.12.128

Synergistic engineering of P, N-codoped carbon-confined bimetallic cobalt/nickel phosphides with tailored electronic structures for boosting urea electro-oxidation

J Colloid Interface Sci. 2024 Mar 15:658:846-855. doi: 10.1016/j.jcis.2023.12.128. Epub 2023 Dec 23.

Authors

Ying Wu¹, Jingfei Kang¹, Houde Liao², Sha Chen³, Jiahao Pi¹, Jianjie Cao¹, Yan Qing¹, Han Xu⁴, Yiqiang Wu¹

Affiliations

¹ College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China.
² College of Science and Technology, Wenzhou-kean University, Wenzhou, Zhejiang 325000, PR China.
³ College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China. Electronic address: chens@csuft.edu.cn.
⁴ College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China. Electronic address: xuh@csuft.edu.cn.

PMID: 38157609
DOI: 10.1016/j.jcis.2023.12.128

Abstract

Bimetallic phosphides exhibit superior electrocatalytic activities and synergistic effects that make them ideal electrocatalysts for the urea oxidation reaction (UOR). Herein, P, N-codoped carbon-encapsulated cobalt/nickel phosphides derived from NiCo-MOF-74 (NiCoP@PNC) and anchored on P-doped carbonized wood fiber (PCWF) for UOR were prepared through synchronous carbonization and phosphorization. By benefiting from the synergistic effect of structural and electronic modulation, NiCoP@PNC/PCWF exhibits excellent UOR electrocatalytic performance under alkaline conditions, achieving a current density of 50 mA cm^-2 with a potential of only 1.34 V (vs reversible hydrogen electrode, RHE) and continuous operation for more than 72 h. In addition, for the overall urea splitting, an electrolyzer using UOR replaced OER, which required only 1.50 V to achieve a current density of 50 mA cm^-2 with excellent stability, 230 mV less than that required for the HER||OER system. In-depth theoretical analysis further proves that the strong synergistic effect between Co and Ni optimizes electronic structures, yielding excellent UOR properties. The synergistic strategy of structural and electrical modulation provides broad prospects for the design and synthesis of excellent UOR electrocatalysts for energy-saving hydrogen production by using renewable resources.

Keywords: Electrocatalyst; MOF; Synergistic effect; Urea oxidation reaction; Wood fiber.