Abstract.A comparison synthetic strategy of Metal-Organic Frameworks, namely, Hongkong University of Techhnology-1 {HKUST-1[Cu 3 (BTC)] 2 } (BTC = 1,3,5-benzene-tri-carboxylate) through solvothermal and electrochemical method in ethanol:water (1:1) has been conducted. The obtained material was analyzed using powder X-ray diffraction, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermo-Gravimetric Analysis (TGA) and Surface Area Analysis (SAA). While the voltage in the electrochemical method are varied, ranging from 12 to 15 Volt. The results show that at 15 V the texture of the material has the best degree of crystallinity and comparable with solvothermal product. This indicated from XRD data and supported by the SEM image to view the morphology. The thermal stability of the synthesized compounds is up to 320 °C. The shape of the nitrogen sorption isotherm of the compound corresponds to type I of the IUPAC adsorption isotherm classification for microporous materials with BET surface area of 629.2 and 324.3 m²/g (for solvothermal and electrochemical product respectively) and promising for gas storage application. Herein, the methane storage capacities of these compounds are also tested.

Titanium dioxide is a promising catalyst for application in the photodegradation of organic pollutants in water due to its powerful oxidising property and long-term photostability. This study presents the production of titanium dioxide using the sol-gel process, dye sensitisation of the TiO2 electrode, and the performance of that cell. Sensitisation of titanium dioxide was performed using a dye, i.e., Fe(II)-polypyridyl complexes. The photoelectrocatalytic degradation of rhodamine B (RB) using ITO/TiO2/dye as electrode was investigated via a series of potentials, from +1.0 V to −1.0 V, and at various pH and NaCl concentration values (ITO is indium tin oxide conductive glass). The photoelectrocatalytic degradation of RB was performed with a visible light lamp. The change in the absorbance of RB with various potentials indicated that the absorbance of RB in solution systems with the sensitised TiO2 electrodes decreased with increasing anodic potential bias. The degradation cell exhibited better performance when the positive anodic bias was applied. The pH values of RB in solution systems also influence the photoelectrodegradation process because of the different RB species present. NaCl concentration also affects the activity of RB photoelectrocatalytic degradation due to changes in the ionic strength character of the electrolyte.

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Synthesis of graphite/PbTiO3 composite as a catalyst in photodegradation and photoelectrodegradation process of methyl orange have been conducted. The purposes of this research are to study the effect of radiation time, composition of composite, voltage and pH of solution for methyl orange degradation. Photodegradation process of methyl orange was carried out for 5; 10; 15; 20; 25 and 30 min. Ratio of graphite : PbTiO3 (w/w) were varied at 1:3; 1:2; 1:1; 2:1 and 3:1. Meanwhile, the applied voltages were 7.5; 10 and 12.5 V and the photoelectrodegradation was conducted under pH condition of 3; 7; and 11, respectively. The result showed that optimum composition of graphite/PbTiO3 in the methyl orange photodegradation was obtained at 1:1 ratio for 30 min with degradation up to 90.43% ± 0.062. The degradation reaction follows first order reaction with a rate constant of 0.0688 min-1. The optimum voltage is 10 V, in which it reduced the methyl orange concentration up to 92.65% ± 0 with a rate constant 0.0941 min-1 for first order reaction. The optimum pH is pH = 11, that provide methyl orange reduction up to 95.28% ± 0.082.

Photocatalytic and photoelectrocatalytic degradation of methyl violet dye using Graphite/PbTiO3 composites has been conducted. The purposes of this research were to examine photocatalytic and photoelectrocatalytic degradation of methyl violet using Graphite/PbTiO3 composite. Synthesis of Graphite/PbTiO3 composite was successfully performed via sol-gel method by mixing graphite powder, titanium tetra isopropoxide precursor solution (TTIP) and Pb(NO3)2. The Graphite/PbTiO3 composites were characterized using X-Ray Diffraction (XRD), Fourier Transform-Infra Red (FT-IR), and Scanning Electron Microscopy (SEM). The XRD diffractogram and IR spectrum of Graphite/PbTiO3 composite revealed all characteristic peak of graphite and PbTiO3. Photocatalytic degradation process showed that Graphite/PbTiO3 composite with ratio 1/1 decreased concentrations of methyl violet up to 92.20 %. While photoelectrocatalytic degradation processed for 30 minutes at neutral pH and 10 V voltage degraded the methyl violet until 94 %. However, the photoelectrocatalysis is still not significance to improve methyl violet degradation compared with photocatalysis.

Industrialization plays important role in the economy of developing countries, including increasing community welfare. However, the presence of poorly industries waste disposal system has negative impact to the environment. Therefore, it is necessary to overcome this problem with low-cost technology, called adsorption. In this research, silylated-montmorillonite (sMMt) has been successfully prepared as supporting material for adsorption of methylene blue by chitosan. The sMMt was characterized by FTIR, XRD, and elemental mapping techniques. The chitosan/sMMt composites were prepared through dissolution-precipitation method and produced rod-like morphology as observed by SEM. The adsorption process was carried out in a batch method by studying the pH and the adsorption contact time. The adsorption kinetic mechanism of the chitosan/sMMt nanocomposite followed pseudo-second order rather than Lagergren model indicating chemisorption predominant. The addition of silylated-montmorillonite into chitosan enhanced the methylene blue dye removal performance, which evidenced by improving Qe values by 10% compared to chitosan.

This research aims to determine the ability of andisol which is composited with TiO2 as a degrading agent of Rhodamine B dye. The composite was made by sonication and calcination. Each material was characterized by FTIR and XRD. Photodegradation was carried out under a UV lamp with variation of the degradation time for 1, 2, and 3 hours. While the pH variation was carried out at 3, 5, 7, and 9. The photodegradation results were tested using UV Vis spectrophotometer at wavelength of 552 nm. Based on these results, the optimum conditions for photodegradation at pH 5 with irradiation time of 2 hours was 39.55%.

The method of Ti/TiO 2 -NiO photoelectrode prepared by using sol-gel method continued by calcination process was introduced. The prepared TiO 2 -NiO film was observed with XRD and TEM. The anatase-rutile TiO 2 was mainly on the prepared TiO 2 -NiO composite surface electrode. In addition to NiO, the composite also formed NiTiO 3 that increased with increasing calcination temperature. Photoelectrocatalytic degradation of Rhodamine B (RB) using this electrode was investigated, and anodic potential and pH were optimized. RB degradation was investigated under different conditions, and it showed that photoelectrocatalytic degradation could achieve efficient and complete mineralization of organic pollutant. Through comparison of the photoelectrocatalytic oxidation using the Ti/TiO 2 -NiO electrode operated by single photoanode with the Ti/TiO 2 -NiO electrode operated by several photoanode, it was found that the photoelectrocatalytic efficiency of that by series photoanodes was higher. Additionally, photoelectrocatalytic system was performed at the several different photoelectrodes, which verified the higher photocatalytic activity compared with the single photoelectrode.