A nanoporous Three-dimensional graphene aerogel doped with a carbon quantum Dot-TiO2 composite that exhibits superior activity for the catalytic photodegradation of organic pollutants

Three-dimensional (3D) graphene aerogel (3DGA) is an emerging photocatalyst support that imparts improved charge-carrier mobility. In this study, a 3DGA framework doped with carbon-quantum-dot-decorated TiO2 nanosheets (3DGA@CDs-TNs) is fabricated by a hydrothermal method. 3DGA@CDs-TNs is then applied as a catalyst to degrade organic pollutants in aqueous solutions. The degradation rates for Cong-red (CR, 120 mg L-1), Rhodamine B (RhB, 20 mg L-1), and colorless tetracycline (TC, 100 mg L-1) reach 98.7% (after 2 h), 97.6% (after 2 h), and 99.8% (after 40 min), respectively, under visible-light irritation, and these rates are much higher than those for CDs-TNs and 3DGA alone. Meanwhile, the dyed wastewater was collected to verify the practicability of 3DGA@CDs-TNs. These enhanced efficiencies arise from the unique 3DGA@CDs-TNs configuration, in which the conductive 3DGA aerogel acts as an effective electron mediator that connects the CDs-TNs composite fragments, providing channels for fast charge transfer. In addition, 3DGA@CDs-TNs also exhibits excellent stability during recycling experiments, confirming its durability and practicability.

Automated summary

In this study, a novel 3D graphene aerogel doped with carbon quantum dots decorated TiO2 nanosheets was successfully fabricated and applied as an efficient catalyst for degrading organic pollutants in aqueous solutions under visible-light irritation. The unique structure of the 3D graphene aerogel provided fast charge transfer channels, leading to significantly higher degradation rates compared to CDs-TNs and 3DGA alone. Additionally, the 3DGA@CDs-TNs exhibited excellent stability and recyclability during the experiments, confirming its durability and practicality.