Hollow mesoporous organosilica nanospheres with multiple tiny silver nanoparticles: A polymer mediated growth approach and catalytic application

Abstract

The fabrication of nanostructured catalysts based on noble metal nanoparticles has attracted much attention. In this study, multiple tiny Ag nanoparticles loaded hollow mesoporous organosilica spheres (MT-Ag@HMOS) were synthesized by a novel polymer mediated growth approach. During the preparation, polyacrylic acid@hollow mesoporous organosilica spheres (PAA@HMOS) were first produced formed by condensation of organosilica precursor on polyacrylic acid (PAA) colloids; subsequently, tiny Ag nanoparticles were in situ immobilized both in the cavity and on the shell of PAA@HMOS due to their abundant thioether groups and unique structure. The produced materials were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), N2 adsorption-desorption instruments, X-ray diffraction (XRD), and X-ray photoelectron spectra (XPS). The MT-Ag@HMOS exhibited a spherical morphology with an average diameter of about 120 nm, a high surface area of 76.5 m2·g−1, as well as high content of tiny Ag nanoparticles (approximately 3 nm). In addition, the catalytic activities of the MT-Ag@HMOS on 4-nitrophenol (4-NP), Congo red (CR), and Rhodamine B (RhB) reduction in the presence of NaBH4 in aqueous medium were investigated. Experimental results show MT-Ag@HMOS particles are promising candidates for the treatment of waste water supplemented contaminated by 4-NP and various dyes.