Sodium hexatitanate photocatalysts prepared by a flux method for reduction of carbon dioxide with water

Abstract

Flux method was applied to prepare sodium hexatitanate (Na₂Ti₆O₁₃) photocatalysts for reduction of carbon dioxide with water. The preparation conditions were examined, such as the starting material, the flux, the composition in the molten mixture, the holding temperature, and the cooling rate of the molten mixture, so as to obtain several sodium hexatitanate samples consisting of the crystals with various morphologies and sizes. These samples were loaded with 0.1 wt% of Ag cocatalyst nanoparticles (Ag/Na₂Ti₆O₁₃) and examined for photocatalytic reduction of carbon dioxide with water, where carbon monoxide, hydrogen and oxygen were formed as products. It was found that the photocatalytic production rate of carbon monoxide varied with the morphology and the size of the sodium hexatitanate crystals. Among the prepared samples, thick rod-like crystals exhibited high photocatalytic activity for the reduction of carbon dioxide.