Two-step calcination synthesis of 1T/2H mixed-phase MoS2/g-C3N4 with sulfur defects for efficient removal of Cr(VI) from water

In this paper, 1T/2H mixed-phase MoS2/g-C3N4 composites (1T/2H-MG) were successfully synthesized by a simple two-step calcination method and used for Cr(VI) removal from aqueous environment. A series of characterization methods were used to characterize the microstructure and surface morphology of the prepared materials. The experiment results showed that 1T/2H-MG (1:12) composite with good pH and temperature adaptability could completely remove Cr(VI) (100 mg∙L–1) within 50 min and showed an excellent adsorption capacity of 342.06 mg∙g–1. The presence of abundant sulfur defects in 1T/2H-MG composite could provide more adsorption and reduction active sites, which was the main reason for the enhanced removal efficiency of 1T/2H-MG in comparison with pure MoS2 and g-C3N4. This work not only contributes an excellent adsorbent for the wastewater treatment, but also provides evidences for the defects engineering.