Improvement of photocatalytic decomposition of methyl orange by modified MWCNTs, prediction of degradation rate using statistical models

Multi-walled carbon nanotubes (MWCNTs) have been successfully modified with TiO2 nanoparticles via a two-step hydrolysis technique. Firstly, the pristine MWCNTs are functionalized in nitric acid (HNO3) to creation of oxygen containing groups. Secondly, synthesized on surface through method. The samples used as photocatalyst for decomposition methyl orange (MO) dye organic pollutant. characterization using X-ray diffraction pattern (XRD) confirm presence mixture anatase and rutile phases. Regarding photocatalytic performance nanoparticles, it observed that degradation rate MO increases by increasing irradiation time from 5 35 min. variation upon pH suspension reveals maximum minimum acidic (pH = 3) neutral condition 7). Meanwhile, results show leads enhancement rate. analysis variance (ANOVA) both main factors (irradiation pH) their interaction significant influence MO. However, effect is more than interaction. graphical methods verify quality adequacy statistical models prediction