Electronic Modulation of Nickel Disulfide toward Efficient Water Electrolysis

Khang Ngoc Dinh; Yongxiu Sun; Zengxia Pei; Ziwen Yuan; Ady Suwardi; Qianwei Huang; Xiaozhou Liao; Zhiguo Wang; Yuan Chen; Qingyu Yan

doi:10.1002/smll.201905885

Electronic Modulation of Nickel Disulfide toward Efficient Water Electrolysis

Small. 2020 Apr;16(17):e1905885. doi: 10.1002/smll.201905885. Epub 2020 Apr 3.

Authors

Khang Ngoc Dinh^{1

2

3}, Yongxiu Sun⁴, Zengxia Pei³, Ziwen Yuan³, Ady Suwardi⁵, Qianwei Huang⁶, Xiaozhou Liao⁶, Zhiguo Wang⁴, Yuan Chen³, Qingyu Yan^{1

2}

Affiliations

¹ Energy Research Institute@NTU (ERI@N), Interdisciplinary Graduate School, Nanyang Technological University, Singapore, 637553, Singapore.
² School of Materials Science and Engineering Nanyang Technological University, Singapore, 639798, Singapore.
³ School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
⁴ School of Electronics Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 610054, P. R. China.
⁵ Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way Innovis #08-03, Singapore, 138634, Singapore.
⁶ School of Aerospace Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.

PMID: 32243082
DOI: 10.1002/smll.201905885

Abstract

Developing highly efficient earth-abundant nickel-based compounds is an important step to realize hydrogen generation from water. Herein, the electronic modulation of the semiconducting NiS₂ by cation doping for advanced water electrolysis is reported. Both theoretical calculations and temperature-dependent resistivity measurements indicate the semiconductor-to-conductor transition of NiS₂ after Cu incorporation. Further calculations also suggest the advantages of Cu dopant to cathodic water electrolysis by bringing Gibbs free energy of H adsorption at both Ni sites and S sites much closer to zero. It is noteworthy that water dissociation on Cu-doped NiS₂ (Cu-NiS₂ ) surface is even more favorable than those on NiS₂ and Pt(111). Thus, the prepared Cu-NiS₂ shows noticeably improved performance toward alkaline hydrogen and oxygen evolution reactions (HER and OER). Specifically, it requires merely 232 mV OER overpotential to drive 10 mA cm^-2 ; in parallel with Tafel slopes of 46 mV dec^-1 . Regarding HER, an onset overpotential of only 68 mV is achieved. When integrated as both electrodes for water electrolysis, Cu-NiS₂ needs only 1.64 V to drive 10 mA cm^-2 , surpassing the state-of-the-art Ir/C-Pt/C couple (1.71 V). This work opens up an avenue to engineer low-cost and earth-abundant catalysts performing on par with the noble-metal-based one for water splitting.

Keywords: cation tuning; electrocatalysis; electronic modulation; hydrogen generation; overall water splitting; water electrolysis; water splitting.

Abstract

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