High-pressure microwave-assisted synthesis of WSx/Ni9S8/NF hetero-catalyst for efficient oxygen evolution reaction

• Published in: Rare metals Vol. 40; no. 5; pp. 1048 - 1055
• Main Authors: Ma, Xue, Zhang, Xin-Yu, Yang, Min, Xie, Jing-Yi, Lv, Ren-Qing, Chai, Yong-Ming, Dong, Bin
• Format: Journal Article
• Language: English
• Published: Beijing Nonferrous Metals Society of China 01.05.2021; Springer Nature B.V
• Subjects: Biomaterials; Catalysis; Catalysts; Chemical synthesis; Chemistry and Materials Science; Electrocatalysts; Energy; High resolution electron microscopy; Materials Engineering; Materials Science; Metal foams; Metallic Materials; Microscopy; Nanoparticles; Nanoscale Science and Technology; Nickel sulfide; Original Article; Oxygen evolution reactions; Physical Chemistry; Sulfurization; Amorphous WS; Electrocatalyst; High-pressure microwave hydrothermal; S; Ni; Oxygen evolution reaction
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-020-01704-x

Designing the specific crystal phase with better intrinsic activity and more active sites is a very promising strategy for earth-abundant electrocatalysts for oxygen evolution reaction (OER). Herein, a facile two-step method including the high-pressure microwave and the hydrothermal sulfurization is adopted to prepare the WS x /Ni 9 S 8 hetero-catalyst on nickel foam (WS x /Ni 9 S 8 /NF). Firstly, WO 3 polyhedrons homogeneously cover the surface of NF through the high-pressure microwave hydrothermal process. Secondly, WS x /Ni 9 S 8 nanoparticles on the surface of NF can be synthesized after a hydrothermal sulfurization, which has been confirmed by scanning electron microscopy (SEM) elemental mapping and high-resolution transmission electron microscopy (HRTEM). The amorphous WS x and Ni 9 S 8 phase may provide the dual active sites for OER. The electrochemical measurements show that WS x /Ni 9 S 8 /NF has superior OER activity with a low overpotential of 320 mV at the current density of 100 mA·cm −2 , better than those of other samples. The enhanced OER performance may be due to the synergistic catalysis from Ni 9 S 8 phase and high valence of W. Owing to the stable structure of Ni 9 S 8 , the long-term stability of WS x /Ni 9 S 8 /NF for at least 10 h can be obtained. This work may provide a new approach for the doped nickel sulfides crystal phase through high-pressure microwave hydrothermal assistance for OER. Graphic abstract