2D gallium molybdenum selenide grown on a hollow carbon nanofibrous aerogel for high-efficiency electroreduction of nitrogen: Optimized basal plane activity via selenium vacancy modulation

Abstract

Herein, a novel, Se-vacancy-modulable Ga–Mo–Se layered compound (GayMo1–ySe2–x) is synthesized by rational incorporation of two different kinds of 2D chalcogenides, i.e., transition metal dichalcogenide (MoSe2) and post-transition metal monochalcogenide (GaSe). The strained effect originating from their lattice misfit (∼13 %) and the electron nonequilibrium between Mo4+ and Ga2+ induce abundant Se vacancies, whose concentration can be arbitrarily modulated to optimize the basal plane activity. Moreover, a highly porous and conductive hollow carbon nanofibrous aerogel is synthesized for the first time, which serves as an ideal matrix for the in-situ growth of 2D GayMo1–ySe2–x due to integrated 3D percolation network and sufficient electrode–electrolyte contact. The unique architecture and optimized activity contribute to an advanced catalyst towards high-efficiency N2 fixation, delivering an NH3 yield of 2.57 × 10–10 mol s–1 cm–2 and a Faradaic efficiency of 26.5 % at –0.3 V vs. RHE in 0.1 M Na2SO4.