The effects of concentration based on the absorbance form the ultraviolet–visible (UV-VIS) spectroscopy analysis

Abstract

This experiment utilizes the material characterization technique known as UV-Vis spectroscopy. The aim of this research is to study the UV-Vis absorption spectroscopy readout in order to investigate the effect of concentration on absorbance for gold solution and to determine the value of band gap for powder sample (TiO 2 ). The types of TiO 2 specimens can be characterized on a solid form of powder, thin film and/or in a liquid form. The preparation of each state of specimen are varies. In this current research, Liquid samples of Au nanoparticles dispersed in different concentrations of ethanol were characterized using UV-Vis technique. The absorbance versus concentration plot of the Au-ethanol samples were found to obey Beer’s law. When examining the solid state in a form of TiO 2 powder, the sample need to be packed before running the experiment. To calculate the band gap of each matter from the reflectance data of UV-Vis, the graph of energy (eV) versus is plotted. The J-curve is identified quickly, extrapolating the tangent to intersect the x-axis to obtain the band gap value.