Preparation of Mesoporous Tio2/G-C3n4 And Visible-Light-Driven Photocatalytic Reduction of Cr6+

Abstract

The pollution and harm caused by heavy metal ions, such as Cr6+ and As5+ is becoming a social issue. TiO2/g-C3N4 photocatalytic reduction is a satisfied method to remove Cr6+. In this work, not only the preparation of TiO2/g-C3N4, using sol-gel blending method, but also the photocatalytic reduction and mechanism were investigated wholly. Mesoporous TiO2/g-C3N4 has rich mesoporous structure and low conduction band gap for the removal of Cr6+. In potocatalytic reduction, Cr6+ is reduced to Cr3+ on the surface of photocatalysts, so it is best for photocatalysts with high adsorption capability. And the reduction is dominated by photocatalytically excited electrons and ·O2-. The influence factors are also researched in detail in order to determine the optimal condition. Its reaction kinetics equations have also been hypothesized to be more consistent with first-order reaction kinetics.These results reveal the feasibility of using mesoporous TiO2/g-C3N4 to reduce the Cr6+ from wastewater and provide a new and excellent catalyst in the photocatalytic reduction.

Keywords: mesoporous TiO2/g-C3N4, sol-gel blending method, Cr removal, reaction kinetics equations.