Hydrothermal synthesis of a photocatalyst based on Byrsonima crassifolia and TiO2 for degradation of crystal violet by UV and visible radiation Article uri icon

abstract

  • This work presents a one-step synthesis methodology for preparing a hydrochar (HC) doped with TiO2 (HC-TiO2) for its application on the degradation of crystal violet (CV) using UV and visible radiation. Byrsonima crassifolia stones were used as precursors along with TiO2 particles. The HC-TiO2 sample was synthesized at 210 degrees C for 9 h using autogenous pressure. The photocatalyst was characterized to evaluate the TiO2 dispersion, specific surface area, graphitization degree, and band-gap value. Finally, the degradation of CV was investigated by varying the operating conditions of the system, the reuse of the catalyst, and the degradation mechanism. The physico-chemical characterization of the HC-TiO2 composite showed good dispersion of TiO2 in the carbonaceous par-ticle. The presence of TiO2 on the hydrochar surface yields a bandgap value of 1.17 eV, enhancing photocatalyst activation with visible radiation. The degradation results evidenced a synergistic effect with both types of ra-diation due to the hybridized & pi; electrons in the sp2-hybridized structures in the HC surface. The degradation percentages were on average 20%25 higher using UV radiation than visible radiation under the following condi-tions: [CV] = 20 mg/L, 1 g/L of photocatalyst load, and pH = 7.0. The reusability experiments demonstrated the feasibility of reusing the HC-TiO2 material up to 5 times with a similar photodegradation percentage. Finally, the results indicated that the HC-TiO2 composite could be considered an efficient material for the photocatalytic treatment of water contaminated with CV.

publication date

  • 2023-01-01