Synthesis of g-C 3 N 4 /TiO 2 nanostructures for enhanced photocatalytic reduction of U(vi) in water.

Photocatalytic technology is a valid solution for the remediation of wastewater containing uranium. In this study, the synthesis of Z-scheme g-C 3 N 4 /TiO 2 catalysts was made by a thermal synthetic approach for photocatalytic U(vi) reduction. The characterization results revealed the successful synthesis of g-C 3 N 4 /TiO 2 nanostructures. The g-C 3 N 4 surface was uniformly coated with TiO 2 nanoparticles. The depletion of U(vi) in water evaluated the photocatalytic activity of g-C 3 N 4 /TiO 2 under UV light irradiation. The photocatalytic tests showed that g-C 3 N 4 /TiO 2 exhibited more effective photocatalytic activity than the raw materials (1.64 and 56.97 times higher than TiO 2 (P25) and g-C 3 N 4 , respectively). Besides, a pseudo-first-order model was followed by the experimental kinetic data for the photocatalytic process. Moreover, g-C 3 N 4 /TiO 2 still presented high photocatalytic activity after four reacting cycles. Based on these experiment results, the improved photocatalytic activity could be attributed to the Z-scheme mechanism, which decreased the recombination of photo-produced electrons and holes. The synthesis of these g-C 3 N 4 /TiO 2 nanomaterials provides a facile and inexpensive method for treating wastewater containing U(vi).