Hydrazine reduction of metal ions to porous submicro-structures of Ag, Pd, Cu, Ni, and Bi

Porous submicro-structures of Ag, Pd, Cu, Ni, and Bi with high surface area have been prepared by the reduction of hydrazine in glycerol–ethanol solution at room temperature or 120–180 °C. Phase purity, morphology, and specific surface area have been characterized. The reactions probably undergo three different mechanisms: simple reduction for Ag and Pd, coordination-then-reduction for Cu and Ni, and hydrolysis-then-reduction for Bi. The reductant hydrazine also plays an important role to the formation of the porous submicro-structure. The reaction temperature influences the size of the constituent particles and the overall architecture of the submicro-structure so as to influence the surface area value. The as-prepared porous metals have shown the second largest surface area ever reported, which are smaller than those made by the reduction of NaBH4, but larger than those made by hard or soft template methods.

Graphical abstractPorous submicro-structures of Ag, Pd, Cu, Ni, and Bi with high surface area have been prepared by the reduction of hydrazine in the glycerol–ethanol solution at room temperature or 120–180 °C. The reactions undergo different mechanisms: simple reduction for Ag and Pd, coordination-then-reduction for Cu and Ni, and hydrolysis-then-reduction for Bi.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Syntheses of porous Ag, Pd, Cu, Ni, and Bi with high surface area. ► Ag and Pd undergo simple reduction. ► Cu and Ni undergo coordination-then-reduction. ► Bi undergoes hydrolysis-then-reduction. ► The as-prepared metals have shown the second largest surface area ever reported.