One-step preparation of a novel SrCO₃/g-C₃N₄ nano-composite and its application in selective adsorption of crystal violet

A novel kind of nanoparticle SrCO₃/g-C₃N₄ was prepared using strontium carbonate (SrCO₃) and melamine (C₃H₆N₆) as raw materials via one-step calcination. The formation of SrCO₃/g-C₃N₄ was confirmed from the X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET) and X-ray photoelectron spectroscopy (XPS) analysis. Its selective adsorption performance was evaluated towards crystal violet (CV), rhodamine B (RhB) and methylene blue (MB). The results showed that the SrCO₃/g-C₃N₄ had selective adsorption ability of CV. Furthermore, adsorption measurements of CV were conducted to investigate the influences of contact time, initial concentration, initial dye solution pH value and adsorbent dosage. The maximum removal rate of CV was 98.56% when the initial concentration was 1600 mg L^-1. The kinetic study indicated the adsorption of CV followed the pseudo-second-second model well. The adsorption efficiency of SrCO₃/g-C₃N₄ was greater (97.46%) than that of g-C₃N₄ (31.30%) and SrCO₃ (17.30%). It could be deduced that the synergistic effect of conjugation interaction of g-C₃N₄ and the electrostatic attraction of SrCO₃ might be the main driving force for the superb adsorption of CV.