Rh/polymeric carbon nitride porous tubular catalyst: visible light enhanced chlorophenol hydrodechlorination in base-free aqueous medium

Abstract

A self-assembled novel porous tubular Rh/polymeric carbon nitride (PCN) photocatalyst was prepared by a simple impregnation reduction method. Both SEM and XRD revealed that PCN was dispersed and curled in an alcohol–water mixture during the impregnation process; Rh/PCN further self-assembled into a novel porous tubular structure in the course of NaBH₄ reduction. Small Rh(0) nanoparticles were uniformly dispersed on the self-assembled PCN (TEM), which was beneficial for improving the separation efficiency of photogenerated electrons and holes, enhancing light absorption and facilitating the photocatalytic hydrodechlorination (HDC) process. Highly promoted catalytic activity (3.12 fold promotion in TOF) and excellent reusability could be achieved in the chlorophenol HDC under ambient base-free conditions with visible light. The harmful chlorophenols were easily converted to high-value cyclohexanol and cyclohexanone in the catalytic process. In combination with a series of characterization techniques, a possible mechanism of Rh/PCN photocatalytic HDC was proposed.