Self-powered H(2) production with bifunctional hydrazine as sole consumable

Splitting hydrazine into H(2) and N(2) by electro-catalyzing hydrogen evolution and hydrazine oxidation reactions is promising for replacing fossil energy with H(2). However, current hydrazine splitting is achieved using external powers to drive the two reactions, which is inapplicable to outdoor use. Here, Fe-doped CoS(2) nanosheets are developed as a bifunctional electrocatalyst for the two reactions, by which direct hydrazine fuel cells and overall-hydrazine-splitting units are realized and integrated to form a self-powered H(2) production system. Without external powers, this system employs hydrazine bifunctionally as the fuel of direct hydrazine fuel cell and the splitting target, namely a sole consumable, and exhibits an H(2) evolution rate of 9.95 mmol h(−1), a 98% Faradaic efficiency and a 20-h stability, all comparable to the best reported for self-powered water splitting. These performances are due to that Fe doping decreases the free-energy changes of H adsorption and adsorbed NH(2)NH(2) dehydrogenation on CoS(2).