Karakteristik Sifat Optik Nanopartikel Karbon (Carbon Dots) Dengan Metode Uv-Vis DRS (Ultraviolet-Visible Diffuse Reflectance Spectroscopy)

Abstract

Research on the synthesis of Carbon Dots using the laser ablation method has been carried out at a time duration of 1, 2, and 3 hours (energy 60 mJ, wavelength 1064 nm and frequency 10 Hz). This research uses organic material from Tea and Toluene as the carbon solvent. The characterization method uses a UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS) spectrum to measure the reflectance value and uses the Kubelka-Munk equation to determine the relationship between the absorbance coefficient parameter (s) and the scattering reflectance coefficient (k). The size and morphological characterization methods used Particle Size Analyzer (PSA) and Transmission Electron Microscopy, while the functional group characteristics used the Fourier Transform InfraRed (FTIR) tool. FTIR spectra show the O-H group which is a hydroxyl bond and N-H is a carboxylic acid. The results of measurement and analysis of bandgap energy at different time durations for direct transition (n=2) were 1 hour (3.62 eV, 342.49 nm), 2 hours (3.24 eV, 380.61 nm) and 3 hours (2.74, 451.82 nm). Indirect transitions (n=1/2) were 1 hour (3.17 eV, 391.02 nm), 2 hours (2.50 eV, 495.36 nm) and 3 hours (2.21 eV, 559.04).

The Effect of Compositional Optical Analysis of ZnO/TiO2 Composites In a Sunscreen Product

“…The smaller the energy band gap (between the conduction band and the valence band), the easier it is for electrons on the valentine band to jump into the conductive band [22]. The smaller the energy band gap (between the conduction band and the valence band), the easier it is for electrons on the valentine band to jump into the conductive band [20]. Given that the overlapping tape is caused by recombination of electrons and holes across the conduction and valence tapes (band gap) and the emission of shallow surface traps due to oxygen vacuum trap (Vo) conditions, it was concluded that the energy of the gap generated for each change was within the energy gap range of semiconductor materials.…”

“…It is important to know that the formula for the physical characterization of this tool is absorbance, reflectance, transmittance, and energy (bandgap) for this data processing. Band gap energy calculation using UV-Vis Diffuse Reflectance The UV-Vis Diffuse Reflectance spectrophotometric approach is used to generate spectroscopy [20]. The calculated reflectance is the value given in the equation ( 2), and it is used to calculate the Kubelka-Munk equation (equation 3).…”