Microwave-assisted thermochemical conversion of Zr-FeOOH nanorods to Zr-ZnFeO nanorods for bacterial disinfection and photo-Fenton catalytic degradation of organic pollutants.

Herein, we report a CoO-loaded Zr-doped ZnFeO (CoO/Zr-ZFO) NR photocatalyst synthesized by successive microwave and wet impregnation methods for bacterial inactivation and degradation of organic pollutants. For the first time, microwave treatment was used for Zn attachment on hydrothermally synthesized self-assembled Zr-FeOOH NRs to produce Zr-doped ZnFeO (Zr-ZFO) NRs. The lowest bandgap energy (1.96 eV) enables for significant absorption in the visible light region, which helps to improve bacteria degradation inactivation efficiency. Further, various metal oxides (Cu, Ag and Co) were loaded onto the surface of photocatalysts (Zr-ZFO NRs) by a wet impregnation method. As-synthesized CoO/Zr-ZFO-3 NRs were systematically characterized and used as photocatalysts for inactivation of E. coli and S. aureus and degradation of organic pollutants. The CoO/Zr-ZFO-3 NR photocatalyst exhibited better inactivation efficiency (99.4 %) than other metal oxide-loaded Zr-ZFO NRs (AgO-loaded Zr-ZFO NRs (33.6 %), CuO-loaded Zr-ZFO NRs (77.6 %)). Additionally, the optimum CoO/Zr-ZFO-3 NR photocatalyst showed 98.3 % and 98.1 % degradation efficiencies for BPA and orange II dye, respectively, under visible light irradiation (λ ≥ 420 nm). Therefore, this work affords a novel, simple and rapid approach for the development of photocatalysts which active in visible light for bacterial disinfection and organic degradation.