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 (TaN_x(O_y)/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 TaN_x(O_y) coating (ca. 236 nm) on NF. In 0.5 M H₂SO₄, TaN_x(O_y)/NF exhibited enhanced HER activity with a low onset potential as compared to the bare NF (−50 mV vs. −166 mV). The TaN_x(O_y)/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 TaN_x(O_y) coating towards enhanced HER performance. The enhanced HER catalytic activity is attributed to the synergistic effect between the amorphous TaN_x(O_y) film and the nickel foam.