Two-dimensional assembly of silver nanoparticles for catalytic reduction of 4-nitroaniline

Silver nanoparticles were assembled into a two-dimensional submonolayer structure on the surface of glass slides. The immobilized silver nanoparticles showed excellent catalytic activity for the reduction of 4-nitroaniline by borohydride. The immobilized catalyst can be conveniently recovered from the reaction system, leading to easy monitoring of the catalytic reaction by the spectroscopic methods. Results indicate that the silver nanoparticles function as the electron relay in the catalytic reduction process. The direct contact of 4-nitroaniline molecules with silver nanoparticles is necessary for the electron transfer from the electron-donating molecules to the accepting molecules through the silver nanoparticles.