Unlocking the power of amorphous TiO2-decorated biocarbon composite: Enhanced photocatalytic performance for crystal violet dye degradation

This study presents a comprehensive investigation of the morphological and photocatalytic properties of electrochemically synthesized titanium dioxide (TiO₂), both in its amorphous (non-calcined) and crystalline (calcinated) forms and its composite with biomass-derived carbon (TiO₂@C). The TiO₂ materials were synthesized using a deep eutectic solvent (DES)-based electrochemical method, and their properties were compared with commercial TiO₂ nano-powder (TiO₂_NP). Characterization techniques such as BET, SEM/EDX, XRD, Raman, ATR-FTIR, and XPS were employed to elucidate the structural, textural, and surface chemical properties of the materials. The amorphous TiO₂ (TiO₂@DES) exhibited significantly higher surface area and pore volume compared to commercial TiO₂, while the calcined TiO₂ (TiO₂@DES_400) displayed enhanced crystallinity with an anatase structure. The TiO₂@C composite was prepared via an in-situ decoration of biomass-derived carbon during the TiO₂ electrochemical synthesis. This resulted in a material with a high specific surface area (2214 m 2 g −1 ) and porous structure. This composite demonstrated superior photocatalytic performance for the degradation of crystal violet dye under both UV and visible light irradiation, achieving degradation efficiencies of ~98 % after 5 h. The TiO₂@C composite was further applied to degrade wastewater from leather dye processing, demonstrating its efficacy in real-world applications. These results underscore the potential of the TiO₂@C composite as a sustainable and high-performance photocatalyst for environmental remediation, particularly in wastewater treatment. • TiO 2 @C exhibits superior photocatalytic efficiency under UV/Vis light. • TiO 2 @C offers a high surface area, boosting photocatalysis. • Calcination changes TiO 2 from amorphous to crystalline anatase, confirmed by XRD. • TiO 2 @C enhances reactive oxygen species and dye degradation.