Efficient photoreduction strategy for uranium immobilization based on graphite carbon nitride/activated carbon nanocomposites

Abstract

Uranium removal from aqueous solutions using environmentally friendly photocatalytic technology is a novel approach for resource recovery. Herein, carbon nitride/activated carbon composite materials (CN/AC) were investigated for U(VI) reduction under visible light. An exceptional boost in photocatalytic activity was observed for CN/AC composites (up to 70 times over the conventional bulk g-C3N4). The strong interactive conjugated π-bond structure between g-C3N4 and AC accelerated the migration of carriers and then prolonged the electron lifetime. CN/AC composites exhibited excellent compatibility with different water substrates and were resilience to a wide range of pH changes and abundant competitive anions/cations. Quenching experiments and electron microscopy characterization indicated that U(VI) was reduced by photogenerated electrons and deposited on the edge of CN/AC composites. The low-cost, high-performance carbon-based composite material proposed in this work is a potential candidate for the efficient treatment of radioactive wastewater.