Clinoptilolite supported rutile TiO2 composites: Synthesis, characterization, and photocatalytic activity on the degradation of terephthalic acid

Clinoptilolite supported rutile TiO2 composites were synthesized for the enhancement of its photocatalytic performance in the degradation of the aqueous terephthalic acid solution under UVC illumination by the increase in its surface area and to simplify its recovery from the treated solution after use. The XRD spectra of the composites revealed the formation of pure rutile TiO2 on the surface of the clinoptilolite. The SEM images showed the formation of the spherical TiO2 clusters were composed of nano fibers on the surface of the clinoptilolite. For all composites synthesized, the dispersion of the TiO2 particles on the clinoptilolite led to a surface area larger than that of the bare TiO2 and clinoptilolite. The materials synthesized in the present study exhibited higher catalytic activity compared with the commercial Degussa P25 and anatase. Among the catalysts synthesized the TiO2/clinoptilolite with a weight ratio of 0.5 was found to be the most photoactive catalyst even though it contains a lesser amount of active TiO2. The kinetic of the reactions for different catalyst was found to be consistent with the pseudo-first order kinetic model. The results of the Langmuir-Hinshelwood model showed the slight contribution of the adsorption on the degradation. The activity of the TiO2/clinoptilolite with a weight ratio of 0.5 decreased after repetitive use due to the accumulation of the TPA molecules on the surface of the catalyst.
Scientific and Technological Research Council of Turkey (TUBITAK 104M255-110M451); Science, Technology Application, and Research Center of Ege University (EBILTEM) (2012/BIL/027); Scientific Research Council of Ege University (13MUH031)