Phenolic resin derivatized TiO-walnut shell carbon hybrid materials for solar photocatalytic phenol removal

As a toxic organic pollutant in industrial wastewaters, phenol wastewater treatment is investigated extensively. TiO based photocatalysts are widely used for such applications, due to its ecofriendly properties, ease of preparation, low toxicity and recycle stability. In this study, phenolic-resin-modified TiO (PF/TiO), TiO/WSC (Walnut shell carbon) and PF/TiO/WSC hybrid composites were successfully synthesized by a sol-gel method. The obtained TiO-based composites were characterized by BET, XRD, SEM, FTIR and XPS techniques. The phase characterization results showed that the TiO phase was anatase in the PF/TiO/WSC (300 °C, 2 h) composite. TiO was uniformly loaded on the surface of the WSC, as revealed by a shift in the Ti binding energy. Ti–O–C bonds are formed in the prepared TiO/WSC and PF/TiO/WSC (300 °C, 2 h) photocatalyst. Using a catalyst dosage of 2.0 g/L and an initial phenol concentration of 80 mg/L, the 10%PF/30%TiO/WSC composite showed the best activity with 88% degradation obtained under sunlight for 150 min. The active species of PF/TiO/WSC photocatalytic degradation of phenol were ·OH and ·O, and a photocatalytic degradation mechanism was proposed. The synergistic system of WSC adsorption and the superior photocatalytic performance of phenolic-resin-modified TiO achieved high degradation efficiency of pollutants in water. This research provides an environmentally friendly method for utilizing agricultural wastes and applies a new idea for solar photocatalytic removal of pollutants. Graphical Abstract: (Figure presented.)