Nanoflower Ni5P4 coupled with GCNQDs as Schottky junction photocatalyst for the efficient degradation of norfloxacin

Abstract

• Novel GCNQDs/Ni 5 P 4 Schottky junction photocatalysts were successfully constructed. • The GCNQDs/Ni 5 P 4 composites exhibited excellent photocatalytic activity in removing norfloxacin. • The electronic band structure of GCNQDs and Ni 5 P 4 was studied by DFT calculation. • Enhanced mechanism of GCNQDs/Ni 5 P 4 composites for degradation of norfloxacin was proposed. A noble metal-free photocatalyst, the porous flower spherical Ni 5 P 4 coupled g-C 3 N 4 quantum dots (GCNQDs) was prepared by a simple ultrasonic impregnation method for the degradation of norfloxacin in wastewater. The GCNQDs exhibit obvious quantum confining effect due to its small particle size. For Ni 5 P 4 , its large specific surface area is conducive to the adhesion of GCNQDs, so that GCNQDs/Ni 5 P 4 composite photocatalysts have excellent photocatalytic performance. In addition, the important role of porous Ni 5 P 4 in promoting electron-hole separation and photocatalytic performance was confirmed by experiments and density functional theory (DFT) calculations. It was found that the GCNQDs and Ni 5 P 4 formed a Shottky junction. At the same time, the GCNQDs/Ni 5 P 4 composite photocatalysts showed good stability in the cycle test, which made it become a kind of green, efficient and repeatable photocatalytic material. This work proposed the degradation mechanism of GCNQDs/8% Ni 5 P 4 composite photocatalysts and the possible degradation path of norfloxacin, providing a new idea for the design of highly active composite photocatalysts.