High interfacial charge separation in visible-light active Z- scheme g-C3N4/MoS2 heterojunction: Mechanism and degradation of sulfasalazine.

Examination of highly proficient photoactive materials for the degradation of antibiotics from the aqueous solution is the need of the hour. In the present study, a 2D/2D binary junction GCM, formed between graphitic-carbon nitride (g-C 3 N 4) and molybdenum disulphide (MoS 2), was synthesized using facile hydrothermal method and its photo-efficacy was tested for the degradation of sulfasalazine (SUL) from aqueous solution under visible-light irradiation. Morphological analysis indicated the nanosheets arrangement of MoS 2 and g-C 3 N 4. The visible-light driven experiments indicated that 97% antibiotic was degraded by GCM-30% within 90 min which was found to be quite high than pristine g-C 3 N 4 and MoS 2 at solution pH of 6, GCM-30% dose of 20 mg, and SUL concentration of 20 mgL−1. The degradation performance of GCM-30% was selectively improved due to enhanced visible-light absorption, high charge carrier separation, and high redox ability of the photogenerated charges which was induced by the effective Z-scheme 2D/2D heterojunction formed between g-C 3 N 4 and MoS 2. The reactive radicals as determined by the scavenging study were •O 2 −, and h+. A detailed degradation mechanism of SUL by GCM-30% was also predicted based on the detailed examination of the band gaps of g-C 3 N 4 and MoS 2. [Display omitted] • 2D/2D layered heterojunction of g-C 3 N 4 /MoS 2 showed high degradation performance. • Sulfasalazine degradation was high for consecutive adsorption-photodegradation. • Proper alignment of MoS 2 and g-C 3 N 4 in heterojunction enhanced degradation rate. • Effective & sufficient production of reactive radicals enhanced the removal rate. [ABSTRACT FROM AUTHOR]