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

摘要

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/cm(2) 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.

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