OPTICAL STUDY OF SOL-GEL DERIVED TITANIUM OXIDE MODIFIED WITH SILVER NANOPARTICLES FOR PHOTOVOLTAIC APPLICATIONS

This research explored the optical properties for sol-gel derived titanium dioxide (TiO2) modified with silver nanoparticles (Ag NPs) and its implications for photovoltaic applications. Through a series of experimental procedures, including the synthesis of TiO2 and the incorporation of silver nanoparticle, we have demonstrated that the modification of TiO2 with Ag NPs significantly enhances its optical characteristics.The analysis of the results shows that the spectrum of TiO2 had no obvious absorption peak observed within the visible and near-infrared region, but a sharp peak was noticed around 430 nm at an absorbance value of 1.2 which falls within the ultraviolet region. This peak is due to the transfer of electrons between molecules with a moderate ionicity along the synthetic molecular material. The study also found out that the UV-visible spectrum of the biologically synthesized AgNPs exhibits a wide and broad band from 380nm, which is attributed to the surface plasmon resonance effect. The colour of the reaction solution changes from light brown to dark brown during the reduction process, indicating the formation of AgNPs. This colour change is caused by participation of a redox reaction of silver metal Ag+ ions in silver Ag0 nanoparticles through the active molecules present in the extract of kola pod. The analysis of the results also shows that all samples of TiO2 and TiO2 coated with 1,2 and 3 cycles of AgNPs had high transparency in the visible region and near-infrared region with a sharp fall observed in the ultraviolet region. The optical reflectance of pure TiO2 and TiO2 coated with various cycles of AgNPs were observed to be relatively reflective. There was a progressive increase in reflectance from 360nm to a maximum peak at 900nm before it shows a peak and valley this increase in reflectance is attributed to the increase in roughness.