Applied Materials and Interface 2020

Interface Catalysts of Ni/Co2N for Hydrogen Electrochemistry

Kaixi Sun Tong Zhang Liming Tan Dexia Zhou Yuqin Qian Xiaoxia Gao Fahui Song Hongtao Bian Zhou Lu Jingshuang Dang Hong Gao Jeremy Shaw Shutang Chen Gugang Chen Yi Rao.

American Chemical Society (ACS) Applied Materials & Interface, 2020, 12, 29357-29364.

The development of active, durable, and nonprecious electrocatalysts for hydrogen electrochemistry is highly desirable but challenging. In this work, we design and fabricate a novel interface catalyst of Ni and Co2N (Ni/Co2N) for hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR). The Ni/Co2N interfacial catalysts not only achieve a current density of −10.0 mA cm–2 with an overpotential of 16.2 mV for HER but also provide a HOR current density of 2.35 mA cm–2 at 0.1 V vs reversible hydrogen electrode (RHE). Furthermore, the electrode couple made of the Ni/Co2N interfacial catalysts requires only a cell voltage of 1.57 V to gain a current density of 10 mA cm–2 for overall water splitting. Hybridizations in the three elements of Ni-3d, N-2p, and Co-3d result in charge transfer in the interfacial junction of the Ni and Co2N materials. Our density functional theory calculations show that both the interfacial N and Co sites of Ni/Co2N prefer to hydrogen adsorption in the hydrogen catalytic activities. This study provides a new approach for the construction of multifunctional catalysts for hydrogen electrochemistry.

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