Novel g–C3N4–carbon dots-aggregation/ferrite hybrid heterojunction photocatalyst with excellent visible-light-driven photodegradation performance toward organic pollutants

Abstract In water pollution treatment, photocatalytic technology is attracting intensive attention and photocatalysts have extensively been focused on, but high efficiency still remains expected. Herein, a spherical uniformly-dispersed aggregation photocatalyst of carbon dots (CDs) with g-C3N4 was hydrothermally synthetized through employing glucose as carbon sources for CDs and employing cyanuric chloride and dicyandiamine for the formation of g-C3N4, and then coupling with 10 wt% of new hydrothermal ferrite photocatalyst Ni0.1Co0.9Fe2O4 to fabricate a novel g–C3N4–CDs-aggregation/ferrite hybrid heterojunction photocatalyst through post sintering process. Various techniques including SEM, HRTEM, XRD, XPS, UV–vis and EIS spectroscopy were employed to analyze the as-fabricated ternary hybrid photocatalyst. Due to the uniformly-dispersed modification of CDs to g-C3N4 and the hybrid heterojunction between g–C3N4–CDs aggregation with Ni0.1Co0.9Fe2O4, the targeted hybrid photocatalyst presented excellent visible-light-driven photocatalytic degradation efficiency towards methylene blue, with a high degradation ratio of up to 96.6% in 1 h, corresponding to a photodegradation rate constant k value of up to 0.05127 min−1. Our targeted hybrid photocatalyst shows good structural and photocatalytic stability and electronic radical (e−) is the main active species during photocatalytic process.