Silver-rhenium bi-metallic nanoparticles (Ag-Re) were prepared by the combination of colloidal sols of silver and rhenium at room temperature. The silver and rhenium sols were synthesized by using the chemical reduction of silver nitrate and ammonium perrhenate with sodium borohydride in presence of cetyltrimethylammonium bromide (CTAB). The morphology (shape, size, elemental composition, oxidation states, and crystalline nature) and textural properties (pore size, pore volume, and surface area) of Ag-0-Re-0 were determined with EDX, SEM, TEM, XPS, XRD, and nitrogen adsorption-desorption isotherm. The Ag-0-Re-0 was used as heterogeneous persulfate (S2O82-) activator to generate reactive radical species (SO4-center dot and HO center dot) for the degradation of xylenol orange (XO) at 434 nm. The Ag-Re exhibits higher XO degradation efficiency than that of mono-metallic Ag-0 and Re-0 nanoparticles, respectively. The degradation efficiency strongly depends on the concentrations of S2O82-, XO, pH, temperature, and amount of Ag-0-Re-0. The role of SO4-center dot and HO center dot were established by using ethanol, and tertiary butanol as radical scavengers. The activation energy was found to be 85.2, 63.5, and 32.6 kJ/mol, respectively, to the degradation of XO by activated S2O82- with Re-0, Ag-0, and Ag-0-Re-0.
