Titanium Dioxide Nanotube Arrays with Silane Coupling Agent Modification for Heavy Metal Reduction and Persistent Organic Pollutants Degradation
Among the technologies for removal of deposited heavy metals and degradation of persistent organic pollutants, TiO2 semiconductor catalysts have gained extensive attention owing to their excellent catalytic ability, relatively stable physical and chemical properties and competitive price. But there are still some drawbacks associated with these TiO2 semiconductor catalysts materials such as their weak adsorption and photo-catalysis abilities in managing the organic pollutants and difficulties in recycling the TiO2 powder (P25). Therefore, a new class of TiO2 nanotube arrays (TiO2-NT) was synthesized using silane coupling agent KH570 as a modifier and applied in reducing heavy metals, and degrading phenol and the persistent organic pollutants like Poly Brominated Diphenyl Ethers (PBDEs). The product was thoroughly characterized by SEM, TEM, DTG, AFM, BET, EDS, DRS and XRD, which confirmed that the surface of TiO2 was well modified by KH570. From the degradation experiment of phenol and BDE47, along with the heavy metal reduction experiment we can see that the catalytic efficiency (2h) of the modified catalyst was 5%, 15% and 3% -20% higher than that of the unmodified catalyst, respectively. Results showed that the modified TiO2 nanotube arrays could not only enhance the adsorption effect of catalyst on organic pollutants, but also increase the electronic separation efficiency of hole as a kind of hole scavengers on the surface of catalyst. Results also indicated that this new class of catalyst had advantages both in surface modification and materials recycling, providing a new direction in environment pollution control.