Facile Synthesis of 3D Interconnected Porous g-C3N4/rGO Composite for Hydrogen Production and Dye Elimination

Photocatalytic materials can effectively decompose water to produce hydrogen and degrade pollutants, ameliorating environmental issues. These materials are currently a popular research topic for addressing energy shortages and water pollution issues worldwide. Herein, we prepared composite catalysts with g-C3N4/rGO heterojunctions formed via the stacking of reduced graphene oxide (rGO) nanosheets and three-dimensional (3D) carbon nitride, and the catalysts displayed excellent photocatalytic activity in experiments for hydrogen production (4.37 mmol g−1 h−1) and rhodamine B elimination (96.2%). The results of structural characterization showed that the recombination of rGO has no effect on the morphology of g-C3N4, and the photochemical characterization results showed that the photogenerated electron migration of the prepared composite was accelerated. Additionally, a possible mechanism of enhancement involving synergy between the 3D structure of the catalyst and the g-C3N4/rGO heterojunctions was proposed on the basis of catalyst characterization and photocatalytic experiments. The prepared composite catalysts had large specific surface areas and abundant adsorption sites due to the 3D structure, and the g-C3N4/rGO heterojunction provided high electron mobility, resulting in low recombination of photoinduced electron and hole pairs and high conductivity. Moreover, free radical species that may play a substantial role in the photocatalytic process were analyzed via free radical quenching experiments, and possible catalytic mechanisms were presented in this study.