Phosphorus doping and phosphates coating for nickel molybdate/nickel molybdate hydrate enabling efficient overall water splitting

Autor: Huaning Fan, Renzheng Jiang, Mengjiang Li, Zhong-Shuai Wu, Yingpeng Xie, Danqi Zhao, Hu Lin
Rok vydání: 2022
Předmět:
Zdroj: Journal of Colloid and Interface Science. 606:384-392
ISSN: 0021-9797
DOI: 10.1016/j.jcis.2021.08.035
Popis: Earth-abundant transition metal-based bifunctional electrocatalysts are promising alternatives to noble metals for overall water electrolysis, but restricted by low activity and durability. Herein, a three-dimensional phosphorus-doped nickel molybdate/nickel molybdate hydrate @phosphates core–shell nanorod clusters on nickel foam self-supported electrode was fabricated by a combined hydrothermal and phosphating process. The phosphorus doping and phosphate coating induced by phosphating process bring in a synergistic effect to improve the electrical conductivity, provide abundant active surface sites and accelerate the surface reaction for nickel molybdate/nickel molybdate hydrate (NiMoO4/NiMoO4·nH2O) heterostructures. These advantages enable the self-supported electrode to exhibit high hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activity in 1.0 M KOH with low overpotentials of 148 and 260 mV at 10 mA cm−2, respectively. When it was employed both as anode and cathode, a cell voltage of 1.62 V is only required to reach the current density of 10 mA cm−2 in alkaline solution. Especially, the self-supported electrode reveals outstanding durability, which could maintain over 25 h at 10 mA cm−2 for HER, OER or overall water splitting. This work provides a novel avenue to enhance the electrocatalytic performance of the catalysts by synergistically modulating the intrinsic electrical conductivity, active surface sites and surface reaction.
Databáze: OpenAIRE
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