Synthesis and Characterization of TiO2-CaO and TiO2-CaO-Fe2O3 Photocatalyst for Removal of Catechol

Abstract

TiO₂-CaO and TiO₂-CaO-Fe₂O_3 photocatalysts have been synthesized through the surfactant-assisted sol-gel method. The catalysts were characterized using XRD, FTIR, SEM-ED Sand BET surface area. XRD pattern showed the formation of anatase TiO_2 crystal phase both in TiO₂-CaO and TiO₂-CaO-Fe₂O₃. The TiO₂-CaO has higher crystallinity than TiO₂-CaO-Fe₂O₃. Based on the peak refinement using Rietveld, there are two peaks identified as Fe₂O_3 hematite in the sample TiO₂-CaO-Fe₂O₃.  BET surface area analysis showed that the average pore size of TiO₂-CaO and TiO₂-CaO-Fe₂O_3 catalysts are 8.04 and 8.41 nm respectively, indicating both catalysts are mesoporous.FTIR spectra show that the vibration of Ti-O, Ca-O, and Ca-TiO_2 were observed in both catalysts. SEM images confirm that both catalysts are porous material. The catechol removal using TiO₂-CaO and TiO₂-CaO-Fe₂O_3 improved with the increase of catalyst concentration. After 360 minutes of UV radiation, the removal of catechol using TiO₂-CaO-Fe₂O_3 reached 46.0%, 48.3%, and 69.2%, while when using TiO₂-CaO, it reached 22.1%, 36.8%, and 57.0% for 0.1 g, 0.15 g, and 0.2 g of catalysts, respectively. The photocatalytic activity of TiO₂-CaO-Fe₂O_3 is not so strong compared to TiO₂-CaO catalyst but the catechol adsorption property of TiO₂-CaO-Fe₂O_3 is higher than that of TiO₂-CaO catalyst.