Development of interfacial strong Interaction-enhanced C-F@CuBi2(Ox/N1-x)4/CN Nano-sheet clusters photocatalysts for the simultaneous degradation of tetracycline and reduced Cr(VI)

Abstract

Antibiotics and heavy metal contaminants often co-exist in wastewater, but developing photocatalysts that can remove them simultaneously without secondary contamination and with easy recovery remains a huge challenge. Regrettably, conventional nano-photocatalysts have the inherent disadvantages of high reflectance of sunlight and high electron and hole recombination rates, and more importantly, nanoparticles dispersed in water cannot be efficiently recovered. Herein, we report a p-n heterojunction photocatalyst formed by growing CuBi2(Ox/N1-x)4 (CBON) nano-sheets clusters directly on copper foam (CF) surfaces and introducing N-doped carbon material (CN) on CBON. Such unique nanostructures not only allows visible light to be reflected many times internally, which helps to improve the absorption of visible light, but also provides many active sites for photocatalytic processes and the rapid separation of electrons from holes. The CF@CBON/CN enables simultaneous degradation of tetracycline and reduction of Cr(VI) (97.1% and 98.9% respectively). Moreover, the method of growing CBON/CN nano-sheet clusters on CF overcomes a number of problems (increased interfacial charge transfer impedance, poor structural stability and non-uniform distribution, etc.) associated with conventional methods of combining nanomaterials with recyclable substrates (loading, introduction of adhesives and hybridization, etc.). The Rct of CF@CBON/CN approximate 30 ohms, greatly smaller than conventional powder materials. More than 10 cycles can be achieved without any physical recovery and restoration work. DFT analysis shows that the strong interfacial interaction enhances the conductivity and electron transfer efficiency of the nitrogen-doped heterojunction structure. In addition, we built a simulated photocatalytic filtration unit which achieved efficient degradation of TC and reduction of Cr(VI) (92.8% and 95.1% respectively).