The effect of starch concentration towards gelcasting porous ceramics capability as TiO2 catalyst support in degrading methyl orange (MO) dye

The purpose of this study was to determine the effect of binder concentration on the ability of gelcasting porous ceramics as TiO2 catalyst support in degrading methyl orange (MO) dye. The raw materials are alumina silica contained in the natural clay of South Sulawesi and starch as a binder. Based on previous research, the binder used is toxic, in this study natural binder with low toxicity were used. Binder plays an important role in the process of pore formation in the ceramic body, so in this study, variations in binder concentration were studied. The research steps consist of natural clay preparation and alumina silica content analysis using XRF; synthesis of gelcasting porous ceramics with various binder concentrations of 2%, 4%, 6%, 8%, and 10%; ceramic pore size characterization using the bubble point method; impregnation of TiO2 catalyst using the adsorption method and analysis of the amount of catalyst that was successfully impregnated using XRF; and TiO2 photodegradation test against MO dye. The results showed that the alumina and silica content in the natural clay of South Sulawesi were 11.98% and 71.12%, respectively. The average pore size of ceramic pores increases with increasing binder concentration, the largest average pore radius occurs at 8% and 10% binder concentrations with a size of 1.40 μm. The amount of TiO2 that was successfully impregnated increased with increasing binder concentration up to 8% and decreased at 10%, the highest amount of TiO2 occurred in porous ceramics with a binder concentration of 8% with a TiO2 percentage of 38.9%. The percentage of MO dye that was successfully degraded occurred at a binder concentration of 8%, this is in line with the percentage of TiO2 that was successfully impregnated.