Moderate Bacterial Etching Allows Scalable and Clean Delamination of g-C3N4 with Enriched Unpaired Electrons for Highly Improved Photocatalytic Water Disinfection

Delamination treatment is crucial in promoting the activity of bulk graphitic carbon nitride (g-C3N4). However, most of the currently used methods of exfoliating bulk g-C3N4 to achieve g-C3N4 thin layers suffer from low yield and environmental pollution. Herein, we developed a facile bacterial etching approach for the preparation of high-quality g-C3N4 nanosheets by exfoliating bulk g-C3N4 under room temperature. Morphology and physicochemical characterizations show that the bacteria-treated g-C3N4 (BT-CN) samples, especially BT-CN-2d, have a lamina-like two-dimensional (2D) in-plane porous structure, a significantly enlarged specific surface area (82.61 m2 g–1), and a remarkable narrow band gap (2.11 eV). X-ray photoelectron spectroscopy and electron paramagnetic resonance spectra confirm the dramatic enrichment of unpaired electron in the BT-CN-2d g-C3N4 nanosheets. EIS spectra and photocurrent tests indicate the fast electron transportation. As a result, the representative BT-CN-2d g-C3N4 photocatalyst...