g-C3N4-nanosheet/ZnCr2O4 S-scheme heterojunction photocatalyst with enhanced visible-light photocatalytic activity for degradation of phenol and tetracycline

Abstract Photocatalytic processes based on semiconductors have been regarded as an efficient environmental purification technology to remove different contaminants from wastewater, and summon for impressive photocatalysts is incessant. Herein, a new step-scheme nanocomposite constructed of g-C3N4-nanosheet/ZnCr2O4 heterojunction is synthesized for effective degradation of phenol and tetracycline. The prepared g-C3N4-nanosheet/ZnCr2O4 nanocomposite exhibits photocatalytic performance for phenol and tetracycline degradation more than 5.8 and 22.5-folds greater than bare g-C3N4-nanosheet and 6.2 and 34.2-times larger than pure ZnCr2O4, respectively. The recycling tests also display that about 88.2% and 89.7% of phenol and tetracycline can be photo-degraded by binary g-C3N4-nanosheet/ZnCr2O4 photocatalyst even after five cycles. The prepared binary photocatalyst pursues a step-scheme charge transfer mechanism that leads to the significant photocatalytic activity under visible illumination. The superior photoability is assigned to the excellent visible light-harvesting capability and fast charge separation and transportation characteristics. The present research serves as a principle route to design and extend striking step-scheme g-C3N4-based nanocomposites with promising environmental purification and solar fuel generation usage.