Amorphous nickel phosphide as a noble metal-free cathode for electrochemical dechlorination

Qiufang Yao; Xuefei Zhou; Shaoze Xiao; Jiabin Chen; Islam A Abdelhafeez; Zhenjiang Yu; Huaqiang Chu; Yalei Zhang

doi:10.1016/j.watres.2019.114930

Amorphous nickel phosphide as a noble metal-free cathode for electrochemical dechlorination

Water Res. 2019 Nov 15:165:114930. doi: 10.1016/j.watres.2019.114930. Epub 2019 Jul 30.

Authors

Qiufang Yao¹, Xuefei Zhou², Shaoze Xiao¹, Jiabin Chen³, Islam A Abdelhafeez⁴, Zhenjiang Yu¹, Huaqiang Chu⁵, Yalei Zhang⁶

Affiliations

¹ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
² State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Key Laboratory of Yangtze River Water Environment for Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
³ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China. Electronic address: chenjiabincn@163.com.
⁴ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; UN Environment-Tongji Institute of Environment for Sustainable Development, Tongji University, Shanghai, 200092, China.
⁵ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
⁶ State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China. Electronic address: zhangyalei@tongji.edu.cn.

PMID: 31426006
DOI: 10.1016/j.watres.2019.114930

Abstract

Nickel phosphide (Ni₂P) is an emerging efficient catalyst for the hydrogen evolution and water splitting. Herein, we report that Ni₂P is also a promising catalyst for enhancing electrochemical dechlorination of chlorinated disinfection byproducts (DBPs). Amorphous Ni₂P (ANP) mini-nanorod arrays were in-situ fabricated on nickel foam (NF) via a facile phosphidation process, and then used as a binder-free cathode for electrochemical dechlorination of trichloroacetic acid (TCAA). Results showed that ANP exhibited superior performance on electrochemical dechlorination of TCAA than other metal cathodes (e.g., NF and Pd/C). Scavenging experiments and electron spin resonance (ESR) technique indicated that atomic H* was generated from water reduction through ANP catalysis, and primarily contributed to TCAA dechlorination. Indeed, the superhydrophilic surface of ANP favored electrocatalyst/electrolyte contact, and its low impedance further afforded rapid electron transport from the electrode to water or protons for atomic H* generation. The kinetic modelling and mass balance evaluation revealed the transformation mechanism of TCAA dechlorination. This study is among the first to develop ANP as a binder-free cathode for electrochemical dechlorination, and have important implications for eliminating chlorinated DBPs in water.

Keywords: Amorphous nickel phosphode; Atomic H*; Electrochemical dechlorination; Noble metal-free; Superhydrophilic.

MeSH terms

Catalysis
Electrodes
Halogenation*
Hydrogen
Nickel*

Substances

Nickel
Hydrogen