Targeted Synthesis of Unique Nickel Sulfide (NiS, NiS2) Microarchitectures and the Applications for the Enhanced Water Splitting System

• Published in: ACS applied materials & interfaces Vol. 9; no. 3; pp. 2500 - 2508
• Main Authors: Luo, Pan, Zhang, Huijuan, Liu, Li, Zhang, Yan, Deng, Ju, Xu, Chaohe, Hu, Ning, Wang, Yu
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 25.01.2017
• Subjects: oxygen evolution reaction; nickel sulfides; hollow microspheres; water splitting system; hydrogen evolution reaction; overall synthesized strategy
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.6b13984

Water splitting is one of the ideal technologies to meet the ever increasing demands of energy. Many materials have aroused great attention in this field. The family of nickel-based sulfides is one of the examples that possesses interesting properties in water-splitting fields. In this paper, a controllable and simple strategy to synthesize nickel sulfides was proposed. First, we fabricated NiS2 hollow microspheres via a hydrothermal process. After a precise heat control in a specific atmosphere, NiS porous hollow microspheres were prepared. NiS2 was applied in hydrogen evolution reaction (HER) and shows a marvelous performance both in acid medium (an overpotential of 174 mV to achieve a current density of 10 mA/cm2 and the Tafel slope is only 63 mV/dec) and in alkaline medium (an overpotential of 148 mV to afford a current density of 10 mA/cm2 and the Tafel slope is 79 mV/dec). NiS was used in oxygen evolution reaction (OER) showing a low overpotential of 320 mV to deliver a current density of 10 mA/cm2, which is meritorious. These results enlighten us to make an efficient water-splitting system, including NiS2 as HER catalyst in a cathode and NiS as OER catalyst in an anode. The system shows high activity and good stabilization. Specifically, it displays a stable current density of 10 mA/cm2 with the applying voltage of 1.58 V, which is a considerable electrolyzer for water splitting.