Rapid and efficient photocatalytic reduction of hexavalent chromium by using “water dispersible” TiO2 nanoparticles

Abstract

In the present work, “water dispersible” TiO2 nanoparticles were prepared, and meanwhile, their photocatalytic activity was systematically tested for the reduction of aqueous Cr(VI) ions. It is found that the as-prepared “water dispersible” TiO2 nanoparticles are a highly efficient photocatalyst for the reduction of Cr(VI) ions in water under UV irradiation, and suitable for the remediation of Cr(VI) ions wastewater with low concentration. Compared with commercial TiO2 nanoparticles (P25), the “water dispersible” TiO2 nanoparticles exhibit 3.8-fold higher photocatalytic activity. 100% Cr (VI) ions can be reduced into Cr(III) ions within 10 min when the Cr (VI) ions initial concentration is 10 mg L−1. Moreover, the electrical energy consumption can be obviously decreased using the “water dispersible” TiO2 nanoparticles. These results suggest that the “water dispersible” TiO2 nanoparticles are a promising photocatalyst for rapid removal of Cr (VI) in environmental therapy.