Persulfate-assisted heterogeneous photocatalytic degradation of furfural from aqueous solutions using TiO2–ZnO/biochar composite

Abstract

This study evaluated the performance of TiO2–ZnO/biochar as activator of persulfate (PS) for degradation of furfural. After the successful synthesis of the catalyst, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) methods were used to investigate the properties of TiO2–ZnO/biochar. The findings of this research suggests that under optimal conditions (pH = 3, catalyst dosage = 1 g/L, persulfate concentration = 1.2 mM, and furfural concentration = 10 mg/L), the PS/Catalysts/UV system can remove 96 % of furfural within 15 min. Under ideal conditions, the experimental results fit well with the first-order kinetic model (R2 > 0.95), and the rate constant (Kobs) was derived as 0.195 min−1. The quenching experiments provided further insights that confirmed the participation of SO4°− and OH° radicals in the degradation process. Nevertheless, the evidence strongly supports the idea that SO4°− plays a more prominent and dominant role as the primary radical species responsible for furfural degradation. Based on the obtained results, it can be concluded that the PS/Catalysts/UV system has an appropriate ability to remove furfural from aqueous solutions, which suggests promising perspectives for its practical application in pollutant treatment scenarios.

Keywords

• Furfural removal
• TiO2–ZnO/Biochar
• Persulfate activation
• Heterogeneous process
• Photocatalytic degradation