Three-Dimensional g-C3N4/NH2-UiO-66 graphitic aerogel hybrids with recyclable property for enhanced photocatalytic elimination of nitric oxide

In order to fix the photocatalyst and enhance the efficiency of NO degradation, a three-dimensional (3D) g-C3N4/NH2-UiO-66-rGO (CN/NU6-rGO) aerogel was devised and fabricated via solvothermal reaction and boiling-water bath. Herein, a type-II heterojunction was formed at CN/NU6 composite, and then, the composite was coupled with rGO. The resulting material significantly enhanced the nitric oxide (NO, 600 ppb) removal efficiency under visible-light irradiation. Optimizing the content of CN and rGO to a suitable mass ratio can increase the removal efficiency by 65.4%, which is 2.34 times that of pure NU6. This result is attributed to the construction of type-II heterojunction and the charge transport properties of rGO. The involvement of rGO not only provided extra pathways for charge transfer to prevent electron–hole pairs from recombining, but also fixed the catalyst. Moreover, the hybrid aerogel excellently reduced the harmful by-product NO2. Cycling experiments, along with transient photocurrent response measurements, verified that CN/NU6-rGO had excellent potential for recyclable and sustainable. This work might shed light on the construction of suitable photocatalytic systems with significant improvement of NO removal and convenient storage of catalyst.