Self-supported amorphous TaNx(Oy)/nickel foam thin film as an advanced electrocatalyst for hydrogen evolution reaction

Abstract

Chemical vapor deposited (CVD) amorphous tantalum-oxy nitride film on porous three-dimensional (3D) nickel foam (TaNx(Oy)/NF) utilizing tantalum precursor, tris(diethylamino)(ethylimino)tantalum(V), ([Ta(NEt)(NEt2)3]) with preformed Ta–N bonds is reported as a potential self-supported electrocatalyst for hydrogen evolution reaction (HER). The morphological analyses revealed the formation of thin film of core–shell structured TaNx(Oy) coating (ca. 236 nm) on NF. In 0.5 M H2SO4, TaNx(Oy)/NF exhibited enhanced HER activity with a low onset potential as compared to the bare NF (−50 mV vs. −166 mV). The TaNx(Oy)/NF samples also displayed higher current density (−11.08 mA cm−2vs. −3.36 mA cm−2 at 400 mV), lower Tafel slope (151 mV dec−1vs. 179 mV dec−1) and lower charge transfer resistance exemplifying the advantage of TaNx(Oy) coating towards enhanced HER performance. The enhanced HER catalytic activity is attributed to the synergistic effect between the amorphous TaNx(Oy) film and the nickel foam.