Design of lignin-based TiO2 composite for enhanced photocatalytic activity and its applications

Lignin with TiO 2 necessitates careful consideration of the organic-to-inorganic ratio in order to achieve the desired functional characteristics. This study synthesized a Lignin-TiO 2 hybrid material through a single-step process utilizing the Taguchi design, which significantly enhanced photocatalytic efficiency under visible light. The Lignin-TiO 2 composite demonstrated improved dispersion, negative surface charge, lower bandgap energy, and reduced charge carrier recombination compared to the controls, resulting in a 2.2-fold increase in photocatalytic efficiency for the removal of methylene blue (MB) dye relative to pure TiO 2 . Additionally, lignin was found to be an effective inhibitor of photo-corrosion, significantly enhancing the stability of Lignin-TiO 2 during 690 min of irradiation. The role of OH radicals in MB photodegradation was confirmed by the degradation of coumarin to 7-hydroxycoumarin (7-OHC). Moreover, Lignin-TiO 2 displayed antimicrobial activity against S. aureus and showed potential as a filler in polyvinyl alcohol (PVA), extending the shelf life of cherry tomatoes by up to 7 days. This study presents a promising approach to enhancing visible light-active photocatalysts using renewable materials while highlighting the practical applications of the composite in environmental remediation and the preservation of agricultural products. • Optimizing Lignin-TiO 2 composites with contrasting properties via the Taguchi method. • OH radicals from Lignin-TiO 2 were the dominant species for MB photodegradation. • Lignin-TiO 2 achieved a 2.2-fold increase in methylene blue removal compared to TiO 2 . • Synergy of PVA Film and Lignin-TiO 2 Filler for Cherry Tomato Freshness. • Lignin-TiO 2 inhibited Staphylococcus aureus growth effectively.