Synergistic adsorption and visible-light catalytic degradation of RhB from recyclable 3D mesoporous graphitic carbon nitride/reduced graphene oxide aerogels

In this work, a series of mesoporous graphitic carbon nitride (MCN) nanometer materials, loaded onto the reduced graphene oxide aerogel (rGOA) with macroscopic three-dimensional (3D) porous structure, were prepared using reduction self-assembly method. The composite aerogel of MCN/rGOA hybrid (MCN/GO mass ratio of 3:9) showed the highest adsorption rate of 73.7% for removing rhodamine b (RhB) solution of 20 mg L −1 , whereas the total effect of adsorption and visible-light catalysis reached 95.2% within 80 min. Meanwhile, the material also showed good stability, and the removal rate was still about 89% after repeating the experiments for five times. The material characterization was carried out using various techniques, which indicated that hybrid aerogels were successfully combined. The specific surface increases from 18 m 2 /g of MCN to 149 m 2 /g for MCN/rGOA hybrid. The hybrid aerogel not only has good adsorption effect, but also exhibits adequate photocatalysis. The composite firstly interacts with the RhB through π – π adsorption, and then, the photocatalysis is improved by increasing the electron transfer efficiency and inhibiting the electron–hole recombination for good conductivity. Through scavenger experiments, it is shown that h + free radicals are the dominant oxidizer during photocatalytic degradation.