Co-benefit of silver nanoparticle and titanium dioxide for elemental mercury adsorption

Abstract

Titanium dioxide-supported silver nanoparticles was synthesized by a facile method and studied as a sorbents for elemental mercury (Hg°). The concentration of deposited silver nanoparticles was in the range of 0.1 – 5.0% weight of titanium dioxide powder. XRD and TEM results confirmed that silver nanoparticles with a diameter size ranging from 2–5 nm were successfully deposited on the surface of titanium dioxide. The capacity of the synthesized sorbents in capturing elemental mercury were tested by exposing sorbent to Hg vapor in a static system comparing with the original titanium dioxide and silver nanoparticles. The performance of titanium dioxide for elemental mercury was significantly increased when silver cooperated. Moreover, the capacity of 5.0% silver loading was comparable with the original silver nanoparticles. Through periodic density function theory study it was found that the synergetic effect of titanium dioxide support and silver nanoparticles could presumably due to the electron acceptor characteristic of TiO 2 -supported silver nanoparticles to promote the Hg° adsorption via electron transferred from the Hg° to the deposited silver nanoparticle and the entire TiO 2 support.