Physiochemical properties of TiO2 nanoparticle loaded APTES-functionalized MWCNTs composites and their photocatalytic activity with kinetic study

Abstract

In this study, functionalized-MWCNTs with 3-aminopropyltriethoxysilane (APTES) loaded titania nanoparticles (MWCNTs-APTES-TiO2) were prepared to investigate their physicochemical properties and photocatalytic activity for methyl orange (MO) degradation. The TiO2 nanoparticles, functionalized-MNCNT and composite powders were characterized by XRD, raman, and TEM. The results obtained proved that titania (TiO2) nanoparticles was successfully loaded on APTES-MWCNTs. For application, MWCNTs-APTES-TiO2 composites were used as photocatalyst for degradation of methyl orange (MO) in aqueous solution under UV light irradiation and the result shows that 87% MO was degraded after 180 min. Kinetic analysis indicated that photocatalytic degradation of MO solution by MWCNTs-APTES-TiO2 obeyed second-order kinetic model (R2 > 0.95), supported by half-life equations and graph. Because of the presence of carbon nanotubes accelerated the degradation of methyl orange due to inhibition of electron-hole recombination, the formation of additional hydroxyl radicals and functional groups of the latter had an inhibitory effect on the degradation of methyl orange. This study suggested the MWCNTs-APTES-TiO2 nanocomposite has considerable potential as environmental photocatalyst due to higher degradation rate as compared to bare TiO2. Keywords: Photocatalyst, Titanium dioxide, Multi-walled carbon nanotubes, Methyl orange, Degradation