High efficiency treatment of organic/inorganic pollutants using recyclable magnetic N-heterocyclic copper(II) complex and its antimicrobial applications.

• Facile synthesis of magnetic N -heterocyclic copper(II) complex. • Structural verification of the nanocatalyst by TEM, TG/DTG, FESEM, FTIR, XRD, EDS and VSM analyses. • Catalytic performances of Fe 3 O 4 /SiO 2 -Thiotet-Cu(II) in the 4-NP, CR, MB and Cr(VI) reduction in water. • Catalyst can be reused nine times without any notable decreasing in its catalytic performance. • Antibacterial activity of the Fe 3 O 4 /SiO 2 -Thiotet-Cu(II) nanocatalyst against E. coli and S. aureus. Development of more efficient, low cost and sustainable (nano)catalysts for reduction of various pollutants in water is highly desirable and is still a major challenge. Herein, we report the immobilization of Cu(II)-5-(methylthio)-1 H -tetrazole complex (Thiotet-Cu(II)) on Fe 3 O 4 /SiO 2 superparamagnetic nanoparticles (NPs) through a versatile process and the application of the nanoparticles prepared as highly efficient and recyclable nanospherical catalysts. The as-prepared Fe 3 O 4 /SiO 2 -Thiotet-Cu(II) is used as a recyclable and highly active nanocatalyst in the reduction of hexavalent chromium [Cr(VI)], 4-nitrophenol (4-NP), Congo Red (CR) and Methylene Blue (MB) in aqueous media. The surface nature of Fe 3 O 4 NPs changes after modification, which causes a notable increase in the catalytic prowess and antimicrobial performance. Moreover, the ensuing nanocatalyst remains high reduction efficiency of ~95% after nine cycles without meaningful loss of its efficiency and can be conveniently separated/decanted using an external magnet, demonstrates high recyclability, excellent chemical stability and high potential for practical environmental applications. The present protocol is clean and eco-friendly and does not use any toxic reductants. [ABSTRACT FROM AUTHOR]