Montmorillonite/TiO2 Advanced Hybrid Material Using Sri Lankan Clay: Preparation and Characterization

Abstract

Montmorillonite (MMT) is a naturally occurring crystalline silicate clay mineral. Nano titanium dioxide (nano-TiO2), particularly in the anatase form, is a photocatalyst under ultraviolet (UV) light. Nano-TiO2 is thus added to paints, ceramics, tiles, or other products for its sterilizing, deodorizing and anti-fouling properties and is used as a hydrolysis catalyst. The objective of this research is to enhance the photocatalytic activity of TiO2 by forming a hybrid material with MMT. Therefore, montmorillonite/TiO2 advanced hybrid materials was prepared using montmorillonite clay from Murunkan deposit in Sri Lanka. The cation exchange capacity (CEC) of Murunkan clay was found as 65 meq/100 g. Raw materials, intermediate products, and the MMT/TiO2 hybrid material were analyzed using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). XRD and EDX data analysis revealed the presence of TiO2 in the hybrid material as anatase form. According to XRD and SEM data analysis average particle size of the nano TiO2 was found to be 60 nm. SEM images showed that the microstructure of the clay has not been destroyed during the formation of the MMT/TiO2 hybrid material. UV-Visible spectroscopy was used to measure the effectiveness of the photocatalytic activity of the hybrid material versus nano TiO2 for the degradation of methyl orange. In this experiment methyl orange was used as a model organic pollutant. Experimental results showed that after 4 hours MMT/TiO2 hybrid material degraded 92% of methyl orange while nano TiO2 has only degraded 67% under diffused light. The synthesized MMT/TiO2 advanced hybrid material exhibited much higher efficiency in degrading methyl orange compared to the same weight of nano TiO2 alone.