Visible light-induced photocatalytic degradation of gas-phase acetaldehyde with platinum/reduced titanium oxide-loaded carbon paper

Abstract

Visible light-induced degradation of gas-phase acetaldehyde (CH₃CHO) is investigated using O-deficient reduced TiO_2−x-loaded carbon paper. The carbon paper is synthesized by the pyrolysis of a filter paper, and the reduced TiO_2−x is prepared by the magnesiothermic reduction of commercial anatase TiO₂. The surface areas of the non-carbonized filter paper and carbon papers obtained by carbonization at 400, 600, 800, and 1000 °C are 4.31 m² g⁻¹, 13.57 m² g⁻¹, 466.81 m² g⁻¹, 461.60 m² g⁻¹, and 26.28 m² g⁻¹, respectively. Although the as-prepared carbon papers possess much lower specific surface areas than that of commercial activated carbon (2200 m² g⁻¹), the carbon papers show better adsorption capabilities. The O-deficient reduced TiO_2−x samples exhibit strong visible-light absorption, and the reduced TiO_2−x-loaded carbon papers induce rapid degradation of CH₃CHO and simultaneous generation of CO₂ in both closed-circulation and continuous-flow modes under visible light irradiation (λ > 420 nm), attributed to the efficient adsorption of gas-phase CH₃CHO by the carbon paper and the rapid and complete degradation of CH₃CHO to CO₂ by the active reduced TiO_2−x. This strongly suggests that the reduced TiO_2−x-loaded carbon paper is an efficient composite photocatalyst for the visible light-induced photocatalytic degradation of gas-phase CH₃CHO.