Abstract:

Sodium dodecyl sulfate (SDS) and copper oxide both were used to modify titanium dioxide photocatalytic catalysts. SDS was used to prepare hydrophobic titanium dioxide. Copper oxide was used to modify the visible light absorption capacity of titanium dioxide. FTIR, UV-Vis and 3-D fluorescence spectra methods were used to characterize the modified titanium dioxide photocatalytic catalysts. The modified titanium dioxide catalysts were used to treat nitrobenzene wastewater. Four factors including pH, initial nitrobenzene concentration, catalysts dosage and light intensity, were researched in a nitrobenzene degradation system that was treated under visible light. FTIR characterization shows that CC and CHfunctional groups appear on the surface of the catalysts. UV-Vis characterization shows that the catalysts modified by copper oxide have excellent visible light response capacity and their absorption edges reach or exceed 830nm. 3-D fluorescence spectra shows that holeelectrons are separated well after copper oxide and/or SDS is added. The speed of nitrobenzene degradationis fastest when pH is 9, the initial nitrobenzene concentration is 500mg/L, the catalyst dosage is 0.2g/L, and light intensity exceeds 2000μW/cm². A kinetic model is established based on the results. The relative errors of the kinetic constants obtained by the model are between -16.5% and approximately -4.5% with low initial nitrobenzene concentrations, and between -11.3% and approximately 4.6% with high initial concentrations.

Key words: photocatalytic, hydrophobic, kinetic, nitrobenzene