In a recent study published in the Journal of Alloys and Compounds, researchers developed a new composite material, chitosan-biochar/ZnO/NiO, with high potential for photocatalytic degradation of organic pollutants. Combining 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 and photocatalysts enhances pollutant removal, leveraging both adsorption and photocatalytic effects. The composite was synthesized using chitosan as the biochar source and tested under visible light for the degradation of Congo red (CR) dye and the antibiotic tetracycline (TC).

The material demonstrated significantly improved photocatalytic efficiency compared to individual components (ZnO, NiO, and biochar). The composite degraded 94.5% of Congo red within 100 minutes and 90% of tetracycline within 45 minutes, with rate constants of 0.0206 and 0.0377 min⁻¹, respectively. These results were attributed to the synergistic interaction between ZnO, NiO, and biochar, promoting enhanced charge separation and migration via a Z-scheme charge transfer pathway.

This research highlights the potential of biochar-based photocatalysts for sustainable water treatment, especially in removing persistent organic pollutants like dyes and antibiotics. The study provides new insights into the design of efficient and eco-friendly composite materials for environmental remediation applications.