Rapid photocatalytic degradation of tetrabromobisphenol A using synergistic p-n/Z-scheme dual heterojunction of black phosphorus nanosheets/FeSe2/g-C3N4

Abstract

Tetrabromobisphenol A (TBBPA), as a typical brominated flame retardant, has been confirmed to pose potential threats for human health and developed into a global pollutant. Graphitic carbon nitride (g-C3N4) is the most used catalyst for refractory organic pollutants removal, but the weak conductivity and quick recombination of photogenerated carries restrict its practical application. To improve the photocatalytic activity of pristine g-C3N4, a p-n/Z-scheme dual heterojunction photocatalyst (BFC) was designed and prepared by introducing black phosphorus nanosheets and FeSe2 into porous g-C3N4 (CN). Compared to traditional heterojunction catalysts, BFC not only can promote photogenerated carriers directed migration and effective separation, but also can retain higher redox potential for simultaneous generating O2− and OH, which are due to the synergistic effects of built-in electric field formation in p-n heterojunction and bandgap structure optimization by Z-scheme heterojunction. Above advantages promote BFC to achieve 100% TBBPA degradation efficiency in 40 min and 22.6% debromination efficiency in 60 min under visible light irradiation. The superfast reaction rate constant (0.143 min−1) is almost 10 times higher than that of pristine CN. This study proposes a facile design strategy to construct heterojunction photocatalysts and provides an alternative method to rapidly remove TBBPA in water.