Synthesis of Cu-Doped TiO2 on Wood Substrate with Highly Efficient Photocatalytic Performance and Outstanding Recyclability for Formaldehyde Degradation

Abstract

Photocatalytic oxidation is considered one of the most effective ways to remove formaldehyde from indoor air. However, the use of powder photocatalysts is limited by their low adsorption capacity and strong aggregation tendency. Hence, there is a need for a composite material with good cycling stability and high degradation efficiency. In the present study, a unique wood-based composite is produced by arranging Cu–TiO2 nanoparticles on porous structured wood. The porous structure of wood can adsorb formaldehyde, and the abundant functional groups on the surface can act as a reaction platform for anchoring the Cu–TiO2 nanoparticles. Cu doping facilitates electron interaction between TiO2 and Cu, promotes the transfer of charge carriers, lowers the electron–hole recombination rate, and improves the photocatalytic degradation efficiency of formaldehyde. The photocatalytic efficiency of the wood-based composites was highest (85.59%) when the n(Cu)/n(Ti) ratio was 7%. After nine cycles, the wood composites still had a high degradation rate, indicating good recyclability. Overall, this wood composite is an eco-friendly and promising material for indoor air filtration.