Nguyen Thi Huynh Nh, et al (2024) Synthesis of Fe-doped ZnO/biochar nanocomposites for acid orange 7 photodegradation and antibacterial activity under visible light region. Materials Research Express. DOI 10.1088/2053-1591/ad477b

A team of researchers from Dong Thap University and Hue University has developed a novel nanocomposite material that promises to significantly enhance the efficiency of wastewater treatment. This new material, an iron-doped zinc oxide (Fe-ZnO) combined with biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More derived from Phragmites australis (common reed), exhibits remarkable photocatalytic and antibacterial properties when exposed to visible light.

The synthesis process involves the co-precipitation of Fe-ZnO nanoparticles onto a biochar matrix, resulting in a material with a reduced bandgap energy, thereby increasing its photocatalytic activity under visible light. The researchers discovered that the optimal iron concentration (3% molar ratio) in the ZnO lattice improved the degradation of Acid Orange 7 (AO7), a common dye pollutant. This Fe-ZnO/biochar composite achieved a photodegradation efficiency of 93.17%, which is nine times higher than pure ZnO.

Additionally, the Fe-ZnO/biochar composite demonstrated significant antibacterial activity, effectively inactivating 98% of E. coli bacteria in treated water. This dual functionality makes it a highly effective agent for both the degradation of organic pollutants and the disinfection of wastewater.

The biochar used in this study provides a cost-effective and environmentally friendly support material. Its high surface area and porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More enhance the dispersion of ZnO nanoparticles, thereby improving the overall efficiency of the composite.

These findings indicate that Fe-ZnO/biochar nanocomposites could be a game-changer in wastewater treatment, offering a sustainable solution to remove both organic pollutants and pathogenic bacteria. The material’s ability to operate under visible light further adds to its practicality for large-scale applications.