Removal of chlorophenols from water via photodegradation using metal oxide nanoparticles

The main goal of the current study is to investigate the photocatalytic degradation of 4-chlorophenol (4-CP) and 4-chloro-2-methylphenol (PCOC) in aqueous solutions via two synthesized nanoparticle catalysts, titanium dioxide (TiO2) and copper oxide (CuO). The effects of using different light sources, such as UV-lamps and sunlight, as well as three different doping catalyst CuO/TiO2 ratios of 3%, 5%, and 10%, have been studied. In this study, CuO nanoparticles were synthesized from copper (II) chloride dihydrate (CuCl2.2H2O) using the precipitation method and TiO2 nanoparticles were synthesized from titanium (III) chloride (TiCl3) by the sol-gel method. All the synthesis catalysts were evaluated for their shape and usable size using X-ray diffraction (XRD) and electron scanning microscopy (SEM). The Scherrer equation was used to calculate the average size of synthesized nanoparticles; for CuO it was 17.7 nm, and for TiO2 it was 55.91 nm. A UV-vis spectrophotometer was used at a wavelength of 280 nm to evaluate the photodegradation rates of 4-CP and PCOC by measuring the absorbance of aqueous solutions of chlorophenol every 15 minutes for three hours. Several factors that affect the photodegradation of 4-chlorophenol (4-CP) and 4-chloro-2-methylphenol (PCOC) have been discussed for future investigation: pH, catalyst particle concentration, irradiation period, light source, doping concentration, dissolved oxygen, and hydrogen peroxide concentration. Furthermore, the photocatalytic mechanism and its outcomes were thoroughly explained. The results showed that the ratio of 5% CuO:TiO2 nanocomposites achieved the highest percentage of photodegradation (87.6 percent), the percentage of degradation of PCOC was lower than that of 4-CP, which was (71 percent).