摘要
Nanoporous metals have attracted signifi cant attention owing to their excellent physical,chemical,and biological properties.However,preparing ultrafi ne nanoporous metal particles(1–5μm)with specifi c geometries remains challenging.Herein,we report a simple strategy to prepare ultrafi ne fl aky hexagonal nanoporous Au-Cu and Au particles via dealloying.Mg-based alloy ribbons with ultrafi ne fl aky hexagonal Mg-Au(Cu)-Gd particles dispersed in a Mg-Cu(Au)-Gd metallic glassy matrix were prepared.The size and morphology of the precipitated fl aky hexagonal Mg-Au(Cu)-Gd particles were controlled by the solidifi cation process of a Mg 61 Cu 21 Au 7 Gd 11 alloy melt.Ultrafi ne fl aky hexagonal nanoporous Au-Cu particles(diagonal diameter 2.58±0.44μm,ligament size~28 nm),Au-1 particles(diagonal diameter 2.38±0.35μm,ligament size~83 nm)and Au-2 particles(diagonal diameter 2.39±0.44μm,ligament size~66 nm)were prepared via ultrasonic-assisted dealloying of Mg 61 Cu 21 Au 7 Gd 11 alloy ribbons in 0.25 M HCl/ethanol,1 M HCl/ethanol and 0.25 M HNO 3/ethanol solutions,respectively.The ultrafi ne fl aky hexagonal nanoporous Au-Cu and Au particles with a large specifi c surface area have a uniform particle size and shape,implying that they possess adequate powder fl uidity and excellent catalytic properties.Moreover,the formation mechanism of the MgAu(Cu)Gd phase in solidifi ed Mg-Cu-Au-Gd alloys was discussed.This study provides a novel approach for synthesizing nanoporous metal particles with a specifi c geometry.
基金
financially supported by the National Key Research and Development Program of China(No.2021YFB3800504)
the Tianshan Innovation Team Program of Xinjiang Uygur Autonomous Region(Grand No.2020D14038)
the Department of Education of Guangdong in China(Nos.2021KCXTD050,2018KZDXM069)
the National Natural Science Foundation of China(Grant No.51871056)。
