Porous TiO2 with large surface area is an efficient catalyst carrier for the recovery of wastewater containing an ultrahigh concentration of dye

Abstract

The preparation of porous TiO₂ as a carrier for the Fenton reaction is reported. Porous TiO₂ is an excellent carrier to load with elemental iron due to the large specific surface area and negative surface charge. Porous TiO₂ was synthesized in the form of a hierarchically porous silica monolith that was used as a microreactor, and a block copolymer served as a template for mesoporous forms. The crystalline TiO₂ growing in confined spaces maintained the porous structure and high crystallinity. The surface area of our synthesized porous TiO₂ can reach 205 m² g⁻¹. The zeta potential of the TiO₂ was as low as −36.5 mV (pH 7). Elemental iron was highly and uniformly dispersed over the channel of the porous TiO₂ via an impregnation method and served as the catalyst for the Fenton reaction. In the Fenton reaction, the synthesized catalyst performed strong catalytic activity during the degradation of wastewater containing an ultrahigh concentration of aqueous dye, at 400 ppm. The aqueous dye solution was degraded over 95% in 30 min, and the catalyst could be reused many times.