Construction of Cu2O-ZnO/Cellulose Composites for Enhancing the Photocatalytic Performance

Zinc oxide (ZnO) nanoparticles, as a non-toxic, harmless, and low-cost photocatalytic material, have attracted much attention from the scientific and industrial communities. However, due to their small particle size and high surface energy, ZnO nanoparticles are prone to agglomeration. In addition, ZnO nanoparticles only have catalytic activity and electron-hole pairing under ultraviolet light. Therefore, Copper(I) oxide (Cu2O)-ZnO/cellulose composites with excellent photocatalytic performance were fabricated by loading Cu2O crystals and using cellulose fiber substrate in this work. Cu2O can increase the light absorption range (including ultraviolet light and visible light) of ZnO/cellulose composites. Moreover, Cellulose fibers can improve the contact area to pollution and photostability of the Cu2O/ZnO nanoparticles, thereby enhancing the photocatalytic activity. The Cu2O-ZnO/cellulose composite showed the highest photocatalytic activity for Methyl orange (MO) degradation, which was approximately 40% and 10% times higher than those of the ZnO/cellulose and Cu2O/ZnO composites, respectively. Moreover, the degradation rate of phenol reached 100% within 80 min. The highly enhanced activity of the Cu2O-ZnO/cellulose composite is attributed to the enlargement of the light absorption range and the formation of heterojunctions between the counterparts, which effectively suppress the recombination of the photogenerated charge carriers. Overall, this work aims to improve the photocatalytic activities of ZnO/cellulose composites by loading Cu2O crystals, hoping to provide a novel and efficient photocatalyst for wastewater treatment.