Enhanced photocatalytic CO2 reduction over Co-doped NH2-MIL-125(Ti) under visible light

Abstract

Co-doped NH₂-MIL-125(Ti) catalysts [Co/NH₂-MIL-125(Ti)] are developed for the photocatalytic reduction of CO₂ upon visible-light irradiation. Compared with NH₂-MIL-125(Ti), Co/NH₂-MIL-125(Ti) exhibits a significantly enhanced activity in CO₂ reduction, due to the fact that the doping of Co nanoparticles onto NH₂-MIL-125(Ti) can promote the visible-light harvesting and electron transfer. In addition, when benzylic alcohols as electron donors, instead of triethanolamine (TEOA) which is often used as a sacrificial agent, are added into the reaction system, Co/NH₂-MIL-125(Ti) can simultaneously catalyze CO₂ reduction to formic acid (HCOOH) and the selective oxidation of the benzylic alcohols to the corresponding aldehydes, making the proposed process more economical and environment-friendly.