One-step dealloying of Ni-Y-Al metallic glass for fabrication of nanoporous hybrid toward efficient water splitting reaction.

The development of high-performance, cost-effectiveness bifunctional catalysts synthesized by convenient strategy has aroused great attention toward water splitting reaction. In this work, the nanoporous catalyst with a sandwich structure, constructed of amorphous alloy matrix and porous layers, was fabricated by one-step dealloying of Ni₂₅Y₆₀Al₁₅ metallic glass for 15 min in citric acid solution. This catalyst, consisting of the hybrid of NiY and NiO, exhibited a uniform three-dimension porous structure with a pore size of about 5–20 nm. The electrochemical measurements indicated that the nanoporous hybrid possesses excellent catalytic performances toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline medium. The overpotentials at 50 mA/cm² are about 0.45 V and 0.52 V for HER and OER, respectively, with low Tafel slopes of 43.9 mV/dec and 116.8 mV/dec. The enhanced electro-catalysis mainly contributed to its large electrochemically active surface area and low interfacial charge transfer resistance. As such, this high-performance, low-cost, and bifunctional nanoporous catalyst has broad application prospects in electrocatalytic water splitting. [ABSTRACT FROM AUTHOR]