Lanthanum ions decorated 2-dimensional g-C₃N₄ for ciprofloxacin photodegradation

The low band gap energy and high surface area two-dimensional materials allow it to tune its basic properties using surface decoration. Here, La³⁺ are decorated on two-dimensional graphitic carbon nitride using a simple and easily scalable chemisorption process with an adsorption capacity of 657.32 mg g^-1. In the X-ray diffraction (XRD) study, the positive slope of the W-H plot elucidates the tensile strain generation (0.103) in La³⁺ ions decorated 2D-g-C₃N₄ (La³⁺-2D-g-C₃N₄). The high-resolution transmission electron microscope (HR-TEM) study and the higher I_D/I_G ratio (0.82) in the Raman spectroscopy study confirm the more defects intensification in La³⁺-2D-g-C₃N₄. The reduction in band gap energy for La³⁺-2D-g-C₃N₄ (from 2.83 eV to 2.21 eV) has shown a good correspondence with the band structures study as obtained from the DFT study. In the DFT study, the significant contributions of N atoms in charge transfer validate the N 1s findings from the X-ray photoelectron spectroscopy (XPS) study for La³⁺-2D-g-C₃N₄. La³⁺-2D-g-C₃N₄ shows the photodegradation efficiency (93%) of ciprofloxacin under UV irradiation, which is superior to pristine 2D-g-C₃N₄ (82%) as well as other g-C₃N₄ based nanocatalysts. Also, La³⁺ decoration results in enhancement (32.3%) in photodegradation kinetics rate. The degradation and kinetics studies in the presence of different scavengers ensure that the O₂- and OH^- radicals are mostly responsible for the ciprofloxacin photodegradation. The Liquid chromatographic-mass spectroscopy and the high-performance liquid chromatography studies confirm the photodegradation. The reusability of La³⁺-2D-g-C₃N₄ is tested up to the fifth cycle. FTIR and UV-visible absorption spectroscopy confirm the stability of the used photocatalyst.