Spatially confined one-dimensional electron transport in hydroxylated MWCNTs-supported Bi₂O₃ heterostructure for enhancing photocatalytic degradation of organic pollutants

Bismuth oxide (Bi 2 O 3 ) is widely used in photocatalytic oxidation degradation of organic pollutants due to its simple composition, green environmental protection and stable structure. However, the limited specific surface area (SSA) and the slow charge kinetics significantly limit its photocatalytic ability. Here, Bi 2 O 3 /MWCNTs heterojunctions were synthesized using hydroxylated multi-walled carbon nanotubes (MWCNTs-OH) as the substrate, explore the crystal growth mechanism and apply it to photocatalytic oxidation reactions. The one-dimensional (1D) structure and excellent electrical conductivity of MWCNTs-OH provide a special transport path for the spatial separation of photogenerated electrons and holes. The stable chemical properties and unique hollow cavity structure of MWCNTs-OH significantly increase the specific surface area of Bi 2 O 3 /CNTs. The optimized Bi 2 O 3 /CNT-3 demonstrated outstanding performance in the photocatalytic oxidation degradation of organic substances such as lignin and RhB. The photocatalytic activity of lignin degradation under visible light has increased by 5.8 times, and the performance of RhB removal has increased by 6.7 times.