Nitrogen Vacancy Structure Driven Photoeletrocatalytic Degradation of 4-Chlorophenol Using Porous Graphitic Carbon Nitride Nanosheets

Incorporating vacancies has been demonstrated as an important approach to alter the catalytic properties of photocatalysts. Herein, a novel porous graphitic carbon nitride (GCN) nanosheet with tunable nitrogen vacancies was synthesized through the thermal treatment of the bulk GCN under an H 2 atmosphere. The resulting porous nanosheets possessed ∼25 nm in thickness, several hundred nanometers in lateral size, and a high surface area of 114 m 2 g –1 . The systematic characterization results revealed that the H 2 treatment induced the structure distortion of GCN with the creation of nitrogen vacancies. As a result, as-prepared nanosheets exhibited considerably enhanced photoelectrocatalytic performances. After 180 min of simulated sunlight irradiation, only 19.5% of the total organic carbon still remained, while 4-chlorophenol was completely eliminated. This enhanced activity was mainly attributed to the increased specific surface area, improved light absorption, and the effective separation and transfer of photogenerated charge carriers, which was confirmed by the photoelectrochemical measurement results. Radical trapping studies revealed that • OH radicals and holes were involved as the major oxygen active species for the degradation of 4-chlorophenol. Our findings offer new insights into designing and developing highly efficient photocatalysts for environmental purification.