Coupling copper and hydrogenated TiO2 to bare TiO2 structures for improved photocatalytic performance

Coupling of metals and hydrogenated TiO₂ (HT) to bare TiO₂ may improve synergistically the photocatalytic activity of TiO₂ for pollutant decomposition. Herein, we address this issue by investigating the photocatalytic performances of Cu‐loaded HT (CuHT)/bare TiO₂ (CuHTT) heterojunction nanocomposites for the degradation of harmful n‐butanol under simulated solar light illumination. CuHTT with a CuHT‐to‐TiO₂ composition ratio of 0.1 showed a photocatalytic efficiency exceeding those of four reference photocatalysts, exhibiting the advantages of improved visible light absorption efficiency, charge carrier separation, and adsorption capacity. Increasing the CuHT‐to‐TiO₂ ratio from 0.01 to 0.1 improved the photocatalytic efficiency of CuHTT, whereas a further increase to 0.9 resulted in a decreased photocatalytic efficiency. Moreover, the photocatalytic efficiency improved as relative humidity increased from 20% to 70%, decreasing upon its further increase to 95%. The efficiencies of n‐butanol to CO₂ conversion over CuHTT were lower than the corresponding decomposition efficiencies. Incompletely oxidized CO and three organic vapors (butanal, propanal, and 1‐propanol) were determined as major intermediates. A possible mechanism for CuHTT‐catalyzed photodegradation under simulated solar illumination was proposed.