Novel [111] oriented γ-Mo2N thin films deposited by magnetron sputtering as an anode for aqueous micro-supercapacitors

•[111] oriented γ-Mo2N thin film was prepared by reactive dc magnetron sputtering.•The formation of (111) texture gives excellent electrochemical property.•The optimum deposition temperature is much lower than that of the chemical route.•The Mo2N film is a promising candidate of anode materials for micro-supercapacitors.

The γ-Mo2N thin films were deposited using reactive dc magnetron sputtering, and tested as an electrode material in an aqueous solution of Li2SO4 with a working potential window of 0.05V∼-0.85 V versus SCE. The morphology, structure and electrochemical properties were systematically studied for the films of different deposition conditions. It was found that the electrochemical property of the γ-Mo2N film depends not only on the deposition temperature but also on the nitrogen concentration in Ar-N2 gas mixture. The sample deposited for 1 h at 400 °C with nitrogen concentration x = 0.35 shows a dense microstructure and strong (111) texture. It exhibits the best electrochemical property, with a high volumetric capacitance of 722 F cm−3 at 5 mV s−1, moderate rate capability with a relaxation time constant of 220 ms, and excellent cycling stability of 100% capacitance retention after 2000 cycles. The (111)-oriented γ-Mo2N film is suggested to be a promising candidate of anode materials for micro-electrochemical-capacitors.

Graphical abstract[111] oriented γ-Mo2N thin film was prepared by reactive dc magnetron sputtering. It exhibits excellent electrochemical property due to the formation of (111) texture and is suggested to be a promising candidate of anode materials for micro-supercapacitors.Download high-res image (284KB)Download full-size image