Co@CoAl‐Layered Double Hydroxide/Nitrogen‐Doped Graphene Composite Catalyst for Al−H2O‐Based Batteries: Simultaneous Hydrogen Production and Electricity Generation

Abstract

AbstractCurrently, the low energy efficiency of water electrolysis has compelled research toward the development of novel and energy‐effective strategies for low‐cost H2 generation. In this context, we report a new concept of simultaneous H2 and electricity generation by separating out the exothermic self‐sustained Al−H2O reaction via electrochemistry. In addition, to catalyze the cathodic water reduction reaction, a single‐pot and environmentally benign synthesis method is adopted. It results in the design of an electrocatalyst composed of Co@CoAl‐layered double hydroxide core‐shell nanospheres anchored over in situ generated N‐doped graphene. Toward the water reduction reaction, the designed catalyst shows a negative voltage shift of mere around 113 mV with respect to the commercial Pt/C catalyst to reach the benchmark 10 mA cm−2, with excellent stability of approximately 86 % voltage retention after 12 h of continuous operation. The catalytic superiority of our material is evident when taken for battery‐level testing; the fabricated device was able to deliver an average output voltage of around 0.95 V at a discharge current density of 5 mA cm−2 along with H2 liberation, which was also detected and quantified through gas chromatography.