Controllable Synthesis of Ni xSe (0.5 ≤ x ≤ 1) Nanocrystals for Efficient Rechargeable Zinc-Air Batteries and Water Splitting

Xuerong Zheng; Xiaopeng Han; Hui Liu; Jianjun Chen; Dongju Fu; Jihui Wang; Cheng Zhong; Yida Deng; Wenbin Hu

doi:10.1021/acsami.8b01651

Controllable Synthesis of Ni _xSe (0.5 ≤ x ≤ 1) Nanocrystals for Efficient Rechargeable Zinc-Air Batteries and Water Splitting

ACS Appl Mater Interfaces. 2018 Apr 25;10(16):13675-13684. doi: 10.1021/acsami.8b01651. Epub 2018 Apr 16.

Authors

Xuerong Zheng¹, Xiaopeng Han¹, Hui Liu², Jianjun Chen³, Dongju Fu³, Jihui Wang¹, Cheng Zhong¹, Yida Deng¹, Wenbin Hu¹

Affiliations

¹ School of Materials Science and Engineering, Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin Key Laboratory of Composite and Functional Materials , Tianjin University , Tianjin 300072 , PR China.
² School of Materials Science and Engineering, Engineering Laboratory of Functional Optoelectronic Crystalline Materials of Hebei Province , Hebei University of Technology , Tianjin 300132 , PR China.
³ Research Institute of Tsinghua University in Shenzhen , Shenzhen 518057 , Guangdong , China.

PMID: 29616794
DOI: 10.1021/acsami.8b01651

Abstract

The development of earth-abundant, highly active, and corrosion-resistant electrocatalysts to promote the oxygen reduction reaction (ORR) and oxygen and hydrogen evolution reactions (OER/HER) for rechargeable metal-air batteries and water-splitting devices is urgently needed. In this work, Ni _xSe (0.5 ≤ x ≤ 1) nanocrystals with different crystal structures and compositions have been controllably synthesized and investigated as potential electrocatalysts for multifunctional ORR, OER, and HER in alkaline conditions. A novel hot-injection process at ambient pressure was developed to control the phase and composition of a series of Ni _xSe by simply adjusting the added molar ratio of the nickel resource to triethylenetetramine. Electrochemical analysis reveals that Ni_0.5Se nanocrystalline exhibits superior OER activity compared to its counterparts and is comparable to RuO₂ in terms of the low overpotential required to reach a current density of 10 mA cm^-2 (330 mV), which may benefit from the pyrite-type crystal structure and Se enrichment in Ni_0.5Se. For the ORR and HER, Ni_0.75Se nanoparticles achieve the best performance including lower overpotentials and larger apparent current densities. Further investigations demonstrate that Ni_0.75Se could not only provide an enhanced electrochemical active area but also facilitate electron transfer during the electrocatalytic process, thus contributing to the remarkable catalytic activity. As a practical application, the Ni_0.75Se electrode enables rechargeable Zn-air battery with a considerable performance including a long cycling lifetime (200 cycles), high specific capacity (609 mA h g^-1 based on the consumed Zn), and low overpotential (0.75 V) at 10 mA cm^-2. Meanwhile, the water-splitting cell setup with an anode of Ni_0.5Se for the HER and a cathode of Ni_0.75Se for the OER exhibits a considerable performance with low decay in activity of 12.9% under continuous polarization for 10 h. These results suggest the promising potential of nickel selenide nanocrystals as earth-abundant and high-performance electrocatalysts for metal-air batteries and alkaline water splitting.

Keywords: HER; NixSe nanocrystals; OER; Zn−air batteries; water splitting.