Simple synthesis of the novel adsorbent BaCO3/g-C3N4 for rapid and high-efficient selective removal of Crystal Violet

Abstract More people have studied the photocatalytic performance of graphitic carbon nitride without paying much attention to its adsorption modification. In this work, we first designed a novel hot dog-like BaCO3/g-C3N4 adsorbent by growing acicular g-C3N4 on insulator BaCO3, which exhibited an effective selective adsorption of crystal violet (CV). The adsorption efficiency of BaCO3/g-C3N4 for 800 mg/L crystal violet in 2 h was 96.67 %, which was far superior to that of solo g-C3N4 (14.40 %) or BaCO3 (7.45 %), and the corresponding maximum adsorption capacity could reach 1240.49 mg/g. The CV adsorption on BaCO3/g-C3N4 followed pseudo-second-order kinetic models and Langmuir isotherms, suggesting that the adsorption process may be controlled by chemical adsorption. Based on the structural analysis of BaCO3/g-C3N4 and the comparison of FT-IR and XPS of samples before and after adsorption, a possible mechanism for effective selective adsorption of CV was proposed, and the synergistic effects of π-π stacking, n-π interaction and hydrogen bonding were deduced to be responsible for the selective and efficient adsorption of CV on BaCO3/g-C3N4.