Boron-Doped Carbon Quantum Dot/Carbon Nanorod/Graphitic Carbon Nitride Composites for Photocatalytic Degradation of Organic Pollutants

Graphitic carbon nitride (g-C 3 N 4 ) has received great attention due to its photocatalytic properties and visible spectrum absorption. However, it has been a challenge for the improvement of the electron–hole separation. Herein, hybridized g-C 3 N 4 containing boron–carbon quantum dots, integrated with boron-doped carbon quantum dots-modified carbon nanorods (CNRs), was designed and fabricated. The boron atoms were doped on carbon quantum dots, and then B-CQDs were assembled on cellulose nanocrystal (CNC) photonic crystals. Using CNC as a nanorod template, carbon nanorods modified with boron-doped CQDs were obtained. Then hybridized g-C 3 N 4 composites containing boron–carbon quantum dots (B-CQDs/CNR/g-C 3 N 4 ) were fabricated. The introduction of boron atoms into CQDs and carbon nanorods improved charge separation and electron conduction. This hybridized B-CQDs/CNR/g-C 3 N 4 significantly elevates the spectral absorption efficiency and charge separation under visible light. It effectively improves the activation of molecular oxygen, leading to the generation of high-energy hydroxyl and superoxide radicals. This composition demonstrates remarkable degradation activity and cycle stability in degrading a nonbiodegradable organic pollutant, tetracycline (TC), suggesting promising applications in energy and environmental fields.