Single-step synthesis of oxygen-doped hollow porous graphitic carbon nitride for photocatalytic ciprofloxacin decomposition

Pollutants degradation via visible-light driven photocatalysts have attracted interest as a potentially efficient and sustainable approach for wastewater treatment. In the present study, a series of oxygen-doped hollow porous surface graphitic carbon nitride (OCN) has been prepared by one-pot thermal polycondensation of melamine with different amounts of polyoxyethylene stearyl ether as the oxygen source and template. The prepared OCN samples were utilized for the photocatalytic ciprofloxacin (CIP) degradation, which is a pharmaceutical waste, under visible light irradiation. The highest degradation performance for CIP was obtained from the OCN sample with 1 mg polyoxyethylene stearyl, which was three times greater than that of pristine C₃N₄. The superior degradation performance of the OCN samples were observed due to the improved light absorption, less recombination rate of photogenerated electron and hole, and enhanced electron transportation, which was proven through the PL, photocurrent density, and EIS results. Thus, the proposed one-pot synthesis of OCN provides an effective method in producing potential photocatalysts for the removal of organic pollutants, such as discarded pharmaceuticals, in wastewater.