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

摘要

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 20mgL(-1), whereas the total effect of adsorption and visible-light catalysis reached 95.2% within 80min. 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 18m(2)/g of MCN to 149m(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 - 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.