Amorphous NiWO4 nanoparticles boosting the alkaline hydrogen evolution performance of Ni3S2 electrocatalysts

• Published in: Applied catalysis. B, Environmental Vol. 274; p. 119120
• Main Authors: Huang, Senchuan, Meng, Yuying, Cao, Yangfei, Yao, Fen, He, Zhujie, Wang, Xuxu, Pan, Hui, Wu, Mingmei
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.10.2020; Elsevier BV
• Subjects: Adsorbed water; Adsorption; Amorphous nanoparticles; Bonding strength; Desorption; Electrocatalysts; Electron density; Heterostructures; Hydrogen; Hydrogen bonding; Hydrogen bonds; Hydrogen evolution reaction; Hydrogen evolution reactions; Hydrothermal; Interfaces; Nanoparticles; Nickel; Nickel compounds; Nickel sulfide; Nickel tungstate; Sulfide; Sulfur; Tungstates; Hydrogen evolution reaction; Hydrothermal; Nickel sulfide; Nickel tungstate; Amorphous nanoparticles
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2020.119120

The strong electronic interaction between NiWO4 and Ni3S2 decreases the local electron density of Ni and S atoms, thus facilitating water adsorption on Ni-sites and hydrogen atom desorption on adjacent S-sites with weakened S−Hads bonds. Thanks to the highly active interfaces, the NiWO4/Ni3S2 electrocatalysts exhibit much better performance than original Ni3S2 toward alkaline hydrogen evolution reaction (HER) with ultra-long stability. [Display omitted] •Amorphous NiWO4 nanoparticles are hydrothermally coupled on the surface of Ni3S2.•The materials exhibit improved HER activity than Ni3S2 with ultra-long stability.•Strong electronic interaction is found between NiWO4 and Ni3S2.•The local electron density of Ni and S atoms is decreased at the interfaces.•NiWO4/Ni3S2 interfaces facilitate water adsorption and hydrogen atom desorption. Heazlewoodite nickel sulfide (Ni3S2) has become attractive for electrocatalytic hydrogen evolution reaction (HER). However, strong sulfur–hydrogen bonds (S–Hads) formed on the surface of Ni3S2 greatly hinder the Hads desorption and reduce HER activity. Herein, amorphous NiWO4 nanoparticles-decorated Ni3S2 electrocatalysts (NiWO4/Ni3S2) have been constructed via a two-step hydrothermal method. The heterostructures exhibit much better HER performance than original Ni3S2 by delivering current densities of −10 and −100 mA cm−2 at low overpotentials of 136 and 274 mV, while those for Ni3S2 are 234 and 424 mV, respectively. Moreover, they display ultra-long stability of 75 h. Theoretical calculation proves the improved activity of NiWO4/Ni3S2 heterostructures is attributed to highly active interfaces between amorphous NiWO4 nanoparticles and Ni3S2 electrocatalysts. The strong electronic interaction between NiWO4 and Ni3S2 decreases the local electron density of Ni and S atoms, facilitates water adsorption on Ni-sites and optimizes hydrogen atom adsorption/desorption on adjacent S-sites with weakened S–Hads.