Biochar-Supported TiO(2)-Based Nanocomposites for the Photocatalytic Degradation of Sulfamethoxazole in Water—A Review

Sulfamethoxazole (SMX) is a frequently used antibiotic for the treatment of urinary tract, respiratory, and intestinal infections and as a supplement in livestock or fishery farming to boost production. The release of SMX into the environment can lead to the development of antibiotic resistance among the microbial community, which can lead to frequent clinical infections. SMX removal from water is usually done through advanced treatment processes, such as adsorption, photocatalytic oxidation, and biodegradation. Among them, the advanced oxidation process using TiO(2) and its composites is being widely used. TiO(2) is a widely used photocatalyst; however, it has certain limitations, such as low visible light response and quick recombination of e(−)/h(+) pairs. Integrating the biochar with TiO(2) nanoparticles can overcome such limitations. The biochar-supported TiO(2) composites showed a significant increase in the photocatalytic activities in the UV-visible range, which resulted in a substantial increase in the degradation of SMX in water. The present review has critically reviewed the methods of biochar TiO(2) composite synthesis, the effect of biochar integration with the TiO(2) on its physicochemical properties, and the chemical pathways through which the biochar/TiO(2) composite degrades the SMX in water or aqueous solution. The degradation of SMX using photocatalysis can be considered a useful model, and the research studies presented in this review will allow extending this area of research on other types of similar pharmaceuticals or pollutants in general in the future.