Nitrogen-doped tungsten carbide nanoarray as an efficient bifunctional electrocatalyst for water splitting in acid

• Published in: Nature communications Vol. 9; no. 1; pp. 924 - 10
• Main Authors: Han, Nana, Yang, Ke R., Lu, Zhiyi, Li, Yingjie, Xu, Wenwen, Gao, Tengfei, Cai, Zhao, Zhang, Ying, Batista, Victor S., Liu, Wen, Sun, Xiaoming
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02-03-2018; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/146; 147/135; 147/143; 639/301/299/886; 639/638/161/886; 639/925/357; Carbides; Catalysis; catalysis (homogeneous), catalysis (heterogeneous), solar (photovoltaic), solar (fuels), photosynthesis (natural and artificial), bio-inspired, hydrogen and fuel cells, electrodes - solar, defects, charge transport, spin dynamics, membrane, materials and chemistry by design, optics, synthesis (novel materials), synthesis (self-assembly); Catalysts; Catalytic activity; Electrocatalysts; Electrodes; Evolution; Humanities and Social Sciences; Hydrogen; Hydrogen bonds; Hydrogen evolution reactions; multidisciplinary; Nitrogen; Noble metals; Oxygen; Oxygen evolution reactions; Reaction kinetics; Science; Science (multidisciplinary); Splitting; Sulfuric acid; Tungsten; Tungsten carbide; Water splitting
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-03429-z

Tungsten carbide is one of the most promising electrocatalysts for the hydrogen evolution reaction, although it exhibits sluggish kinetics due to a strong tungsten-hydrogen bond. In addition, tungsten carbide’s catalytic activity toward the oxygen evolution reaction has yet to be reported. Here, we introduce a superaerophobic nitrogen-doped tungsten carbide nanoarray electrode exhibiting high stability and activity toward hydrogen evolution reaction as well as driving oxygen evolution efficiently in acid. Nitrogen-doping and nanoarray structure accelerate hydrogen gas release from the electrode, realizing a current density of −200 mA cm
−2
at the potential of −190 mV vs. reversible hydrogen electrode, which manifest one of the best non-noble metal catalysts for hydrogen evolution reaction. Under acidic conditions (0.5 M sulfuric acid), water splitting catalyzed by nitrogen-doped tungsten carbide nanoarray starts from about 1.4 V, and outperforms most other water splitting catalysts.
Water electrolysis can generate carbon-neutral hydrogen gas from water, yet the required catalysts are often expensive, scarce, and poor at gas release. Here, the authors prepared nitrogen-doped carbon tungstide nanoarrays with high water-splitting activities and bubble-releasing surfaces.