Recently, the research group of Prof. Jie Zeng from School of Chemistry and Materials Science & Hefei National Laboratory for Physical Sciences at the Microscale has made a breakthrough in the development of electrocatalysts for hydrogen evolution reaction (HER). Researchers designed ultrathin WO₃ nanosheets as an active and stable catalyst for HER through a liquid exfoliation method. This work was published on Nano Letters (Nano Lett. 2017, 17, 7968-7973) entitled as “Conductive Tungsten Oxide Nanosheets for Highly Efficient Hydrogen Evolution”. Graduate students, Tingting Zheng, Wei Sang, and Zhihai He were the co-first authors of this work.

Hydrogen, a clean and sustainable energy vector, is a promising alternative to traditional fossil fuels. Electrocatalytic hydrogen evolution reaction (HER) represents one of the most advanced technologies for hydrogen production. Although Pt-based materials are the most active catalysts for HER, their large-scale application is hindered by high cost and lack of abundance. This limitation has sparked tremendous interests in exploring earth-abundant HER catalysts that could potentially replace Pt.

Herein, they synthesized WO₃ nanosheets with rich O vacancies by liquid exfoliation. Electronic transport measurements disclose the nature of degenerate semiconductor for the WO₃ nanosheets with O vacancies, consistent with our theoretical calculation results. The WO₃ nanosheets rich in O vacancies exhibit a superior HER catalytic performance with a small overpotential of 38 mV at a current density of 10 mA cm^-2 and low Tafel slope of 38 mV dec^-1. Such activity was comparable to that of the commercial Pt/C. The high activity derived from the large surface area of the two-dimensional morphology and the O vacancies which rendered high electrical conductivity and appropriate ΔG_H.

This work was supported by MOST of China and NSFC.

WO₃ nanosheets and their catalytic performance