Abstract
•Carbon-modified (CM)-n-TiO2 nanoparticles were synthesized via a sonicated sol–gel method.•Photocatalytic removal of PCBs from aqueous solution was investigated using CM-n-TiO2.•Carbon modification enhanced the photocatalytic activity of CM-n-TiO2.•The highest removal rate was obtained at pH 5 and catalyst dose of 0.5gL−1.•Photocatalytic removal data were successfully fitted using Langmuir–Hinshelwood model.
In this work, the sonicated sol–gel method was used for synthesizing carbon-modified titanium oxide nanoparticles. Carbon incorporation was achieved by using titanium (IV) isopropoxide as a titanium and carbon-containing precursor. The photocatalytic efficiency of the synthesized photocatalyst was assessed by examining the photocatalytic removal of polychlorinated biphenyls (PCBs) from aqueous solution. For comparison, unmodified (regular) titanium dioxide (n-TiO2) was used as a reference catalyst. To confirm the carbon incorporation in CM-n-TiO2 nanoparticles, energy dispersive spectroscopy (EDS) analysis was used. Significantly, the bandgap energy was found to be reduced from 2.99eV for n-TiO2 to 1.8eV for CM-n-TiO2, which in turn improved the performance of CM-n-TiO2 toward the photocatalytic removal of PCBs. The effects of CM-n-TiO2 loading, PCBs concentration, and pH of the solution on the photodegradation rate of PCBs were investigated. The highest removal rate was found to be at pH 5 and CM-n-TiO2 loading of 0.5gL−1. According to Langmuir–Hinshelwood model, the photodegradation of PCBs using CM-n-TiO2 followed a pseudo-first order reaction kinetics.