Abstract
Endocrine disrupting chemicals (EDCs) and heavy metals are typical emerging pollutants. EDCs can cause the disorder of endocrine systems in biological bodies, which metal ions are poison chemicals to human health. From the environmental sustainability and green chemistry points of view, the development of a high efficient advanced photocatalyst that can remove emerging pollutants and metal ion in the environment is of great important. One-dimensional titanate nanobutes (TNTs) are promising materials for energy and environmental applications. However, the simultaneous removal of bisphenol A and copper ion by TNT are raely reported. In this study, the TNTs were originally obtained from ST-01 TiO2 at hydrothermal temperature of 150 oC for 1 d and then post heat-treatment at 200–600 °C in air for 4 h. The TNTs materials were characterized using SEM, TEM, BET surface area, XRD, UV-Vis, and XAS analyzer. The adsorption of copper ion onto as-synthesized and calcined TNTs was studied. The effects of copper ion concentration, pH value, ionic strength and temperature on adsorption of copper ion by TNTs were also evaluated. Results showed that the fabricated TNTs is a multi-layered tubular structures with diameters of 7-10 nm. The specific surface area of TNTs decreased with the increase in calcination temperature, presumably due to the collapse of tubular structures and formation of anatase TiO2 nanoparticles. The as-synthesized and calcined TNTs have good capacity for Cu(II) adsorption. The calculated maximum Langmurian adsorption capabilities (qm) were 160 ± 11 mg/g for as-synthesized TNTs, 129 ± 6 mg/g for TNT_200, 117 ± 6 mg/g for TNT_300, 105 ± 4 mg/g for TNT_400, 54 mg/g for TNT_500 and 35 mg/g for TNT_600. The adsorption kinetics was evaluated by the pseudo-first-order, pseudo-second-order and intraparticle diffusion model. The pseudo-second-order model fitted the experimental results quite well, and intraparticle diffusion was found to be not the rate limiting step. In addition, the negative value of enthalpy (ΔH) (−57.6 kJ mol−1) indicates the exothermic nature of the adsorption process, and the adsorbed amounts of copper ions onto the as-synthesized TNTs decreased with the increasing reaction temperature as well as the ionic strength. In addition, the photocatalytic activities of the catalyst obtained were evaluated by the degradation of bisphenol A in aqueous solution under UV light irradiation. The effect of environmental parameters including such concentration of bisphenol A and copper, and the pH were investigated by measurement of the rate constant for BPA degradation. Consequently, kinetic parameters were experimentally determined and a pseudo-first-order kinetic was observed. In this study, the photodegradation process of 10 mg/L BPA in the presence of copper ions by TNT_500 had higher rate constant than that in the absence of copper, which is 6.7 times higher than by Degussa P25 TiO2.