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The objective of this research to synthesize the Selenium (Se) doped TiO2/Ti electrode as a novel chalcogenide material by anodizing and dip-coating method. The electrode was applied for Rhodamine B (RhB) degradation test in high-photoelectrochatalytic (PEC) performance. It is found out that the morphology and element containing on Se-TiO2/Ti electrode has honeycomb structure with the element composition of Ti (51.09%), O (36.91%), and Se (12.00%), respectively. In addition, the PEC response test using Linear Sweep Voltammetry (LSV) showed that the optical properties of Se-TiO2/Ti electrode was active under visible light, meanwhile the TiO2/Ti was active under ultraviolet (UV) light. The PEC test using Multi Pulse Amperometry (MPA) technique was exhibited that the 5 ppm RhB corresponded to the degradation of 73.27%.

The degradation of methylene blue dye has been conducted by Ag@S-TiO2/Ti electrode to increase the plasmon effect on visible light. The addition of silver metal was applied using electrodeposition method. While the S-TiO2 was prepared by sol-gel and immobilization on TiO2/Ti electrode. The results showed that the X-ray diffraction pattern of TiO2/Ti electrode was anatase crystal. Fourier transform infrared analysis in the wavenumber of 1120 and 413 cm -1 indicated the existence of S-O and Ti-O bonds. Supporting by scanning electron microscope and energy dispersive X-ray (SEM-EDX) on Ag@S-TiO2/Ti electrode, the existence of Ag, Ti and S were 2.9, 4.5 and 2.3 KeV, respectively. The plasmon effect identity was active on visible light irradiation confirmed by the photoelectrocatalyst system using linear sweep voltammetry (LSV). Based on the UV-visible spectrophotometer measurement the efficiency of methylene blue degradation was 81.15 % on 0.5 ppm.

Preparation of Cu-doped TiO2 nanoparticles (Cu/TiO2) as antifungal Phytophthorapalmivorahas been carried out. In this study, we did a synthesis of Cu/TiO2 nanoparticles by the sol-gel method and determine the performance of the modification of Cu/TiO2 nanoparticles as antifungal agents P. palmivora. The stages of this research include synthesis of Cu/TiO2 nanoparticles using the sol-gel method, characterization of Cu/TiO2 nanoparticles using UV-Vis DRS and characterization of Cu/TiO2 nanoparticles using SEM-EDX, and P. palmivora antifungal activity test. TiO2 is known to be used as an antifungal agent and to increase photocatalyticactivity, TiO2 is doped with Cu metal ions to be active in visible light. The results showed that Cu/TiO2 has a band gap energy of 3.12 eV. Based on the results of SEM-EDX analysis of TiO2-Cu nanoparticles confirmed the presence of elements Cu (2.16%), Ti (28.74%) and O (69.10%) with morphological shapes such as irregular spheres. Cu/TiO2 nanoparticles have a strong ability at concentrations of 0.05% and 2.5% in inhibiting the growth of the fungus P. palmivora. Percent inhibition respectively 60.41% and 75% and at concentrations>3% have activities that can kill P. palmivora fungus.

Electrochemical studies in detecting persistent organic pollutants (POPs) have attracted a lot of interest from researchers, especially the carbon paste electrode (CPE). The research objectives were to determine the electrochemical characteristics of TiO2/Ag-Li on the CPE in the system Fe2+/Fe3+ and determine the fipronil in solution. TiO2/Ag-Li preparation was carried out by using the sol-gel method. Electrochemical performance of CPE was applied by cyclic voltammetry. The system developed was a reversible redox reaction and have peaks Ipa 110 µA and Ipc 105 µA. We also found that the composition of the best modifier addition to CPE was using TiO2/Ag-Li with a mass of 0.005 g. The optimum scan rate for the measurement of the fipronil test solution was obtained at 0.2 V/s with an Ipa value of 15 µA and an Epa value of 0.40 V. Based on the plot between the root scan rate and the oxidation current of the solution containing fipronil, the obtained R2 value was 0.9806. This research provides the development of modifier CPE material with the well electrochemically performance and considered as a very effective monitored system for the environment contaminated by POPs waste.