Facile synthesis of silver-rhenium nanoparticles with plasmonic and mesoporous properties

Cetyltrimethylammonium bromide (CTAB) capped rhenium (Re0@CTA(aq)) NPs were prepared by using chemical reduction method at room temperature in aqueous solution. The resulting Re0@CTA(aq) sol was utilized as sacrificial template and silver ions (Ag+) for the synthesis of silver-rhenium bimetallic NPs (Ag0-Re0@CTA(aq)) under metal displacement galvanic cell reaction in aqueous solution with CTAB. Surface Plasmon resonance (SPR) band intensity and wavelength maxima of Plasmon band of Ag0-Re0@CTA(aq) depends on the concentration of CTAB. The Plasmon band was blue shifted from 434, 439, 519, 535, 465, and 445 nm, respectively, for 0.0, 0.75, 1.0, 1.25, 1.5, and 2.0 mM of CTAB. Oxidation states, crystalline nature, elemental composition, surface morphology, shape, size, and textural properties of as-prepared silver-rhenium were determined with Xray photoelectron spectrometry (EDX), X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and nitrogen adsorption-desorption isotherm (BET). Fourier transform infrared spectrometry (FTIR), 1H NMR, 13C NMR, and gas chromatography-mass spectrometry (GC-EIMS) analysis were used to establish the capping properties of CTAB. Application of FTIR, 1H NMR, 13C NMR and GCEIMS analysis shows that the CTAB consistently remains adsorbed on Ag0-Os0 NPs. Optical properties of plasmonic nanomaterials can be tuned by using a suitable concentration of CTAB surfactant.