Facile Sol-Gel Synthesis of C, N Codoped-TiO for Efficient Degradation of Palm Oil Mill Effluent.

Wastewater treatment has been regarded as an effective solution in lowering the potential environmental hazards caused by palm oil mill effluent (POME). To ensure the efficient remediation of POME, the implementation of a promising strategy is necessary to overcome the limitations of conventional water treatment methods for the treatment of this pollutant. In this study, the synthesis of carbon, nitrogen codoped titanium dioxide nanoparticles (C, N-TiO NPs) was successfully performed by a sol-gel approach for the treatment of POME as a model pollutant under solar light irradiation. The synthesized C, N-TiO NPs displayed unique characteristics including an anatase phase with an average crystallite size of 11.35 nm and irregular spherical structures. Additionally, C, N-TiO possessed a lower band gap energy of 2.95 eV than 3.2 V of bulk anatase TiO and slower electron-hole (e-h) pair recombination rate as evidenced by photoluminescence (PL) studies. The adsorption isotherm study of POME was most compatible with the Langmuir isotherm model, and the POME degradation kinetics proceeded according to first-order kinetics. Accordingly, the photocatalytic degradation of POME displayed a maximum degradation efficiency of 100% under the optimum condition of pH 7 in the presence of 0.12 g of the C, N-TiO photocatalyst within 150 min. The scavenging study showed that the superoxide radical (•O ) was the primary active species in the POME photodegradation. Finally, the reusability analysis confirmed that the C, N-TiO NPs could be reused for a maximum of five cycles, making them promising photocatalysts for wastewater treatment.