An efficient novel NiCu@INA/rGO MOF hollow microsphere Z-scheme heterojunction catalyst for the photocatalytic degradation of tetracycline and simultaneous degradation of cationic and anionic Dyes

Abstract

Bimetallic metal-organic framework materials have captivated considerable attention in photocatalysis because of their colossal properties like semiconducting, large surface area, and potent visible light harnessing ability. Self-aggregation and rapid recombination rates have greatly hindered their applications in photocatalysis. A novel reduced graphene oxide-incorporated bimetallic nickel copper metal-organic framework (NiCu@INA/rGO MOF) is fabricated using isonicotinic acid as an organic linker. A synergistic effect between the two metals increased the photocatalytic performance. Introducing reduced graphene oxide to nickel-copper MOF increased charge carrier retention transfer and enhanced the catalyst's water dispersibility. The efficiency of the photocatalyst for the removal of tetracycline (TCn) and a mixture of Rhodamine B (RhB) and Orange G (OrG) dyes was investigated under visible light. A degradation efficiency of up to 89 % for TCn and close to ∼97.8 % and 93.5 % degradation in the case of RhB and OrG dyes was observed. The studies on the photocatalytic degradation mechanism were explored by conducting radical scavenger experiments, Electron spin resonance (ESR) studies, and Mott-Schottky analysis. TCn and RhB degradation pathways were explored by mass spectral analysis of the intermediates during the photocatalytic degradation of TCn and RhB. This work provides new paradigms for the functional modification of MOF for designing efficient photocatalysis.