Self-supported amorphous TaN x (O y )/nickel foam thin film as an advanced electrocatalyst for hydrogen evolution reaction.

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)(NEt 2 ) 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 H 2 SO 4 , 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 -2 vs. -3.36 mA cm -2 at 400 mV), lower Tafel slope (151 mV dec -1 vs. 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.