The self-assembly of gold nanoparticles in large-pore ordered mesoporous carbons

Simple encapsulation of 3 rim gold nanoparticles in ordered mesoporous carbon with large pores of 17 nm and thick pore walls of 16 nm was achieved by a metal-ligand coordination assisted-self-assembly approach. Polystyrene-block-polyethylene-oxide (PS-b-PEO) diblock copolymer with a large molecular weight of the PS chain and mercaptopropyltrimethoxysilane were used as the template and the metal ligand, respectively. Small-angle X-ray scattering, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy showed that monodispersed aggregation-free gold nanoparticles approximately 3 nm in size were partially embedded in the large open pore structure of the ordered mesoporous carbon. The strong coordination between the gold species and the mercapto groups and the thick porous walls increased the dispersion of the gold nanoparticles and essentially inhibited particle aggregation at 600 degrees C. The gold nanoparticles in the ordered mesoporous carbon are active and stable in the reduction of nitroarenes involving bulky molecules using sodium borohydride as a reducing agent under ambient conditions (30 degrees C) in water. The large interconnected pore structure facilitates the mass transfer of bulky molecules. (C) 2021 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.

Automated summary

By utilizing a metal-ligand coordination assisted-self-assembly approach, three gold nanoparticles were successfully encapsulated in ordered mesoporous carbon with large pores and thick pore walls. The strong coordination between the gold species and the mercapto groups, as well as the thick porous walls, contribute to the dispersion and stability of the gold nanoparticles at high temperatures and their reactivity and stability in water.