Surface modification of nanoparticles with octadecyl trichlorosilane and its effects on photocatalytic activity

The surfaces of titanium dioxide (TiO₂) nanoparticles were modified with octadecyl trichlorosilane (OTS) as a coupling agent in different conditions. In order to improve the nanoparticles´ dispersion and transform the interactions between nanoparticles in different conditions, the grafting of OTS on the TiO₂ nanoparticles´ surface was characterised by thermogravimetric analysis and Fourier transform infrared techniques. An ultraviolet (UV) spectrophotometer was employed to evaluate the absorbance of UV-light in the wavelength range of 200-900 nm. To assess the light catalytic activity, UV/vis diffuse reflectance spectra were applied to detect the absorbance of Rhodamine B, which was absorbed in the dark and degraded under a lamp. An effective method has been provided to improve photocatalytic activity, which may also be applied to the modification of other nanomaterials.