Development of highly efficient magnetically recyclable Cu2+/Cu0 nano-photocatalyst and its enhanced catalytic performance for the degradation of organic contaminations

This work reports the successful functionalization of L-proline on the surface of superparamagnetic iron oxide nanoparticles (SPION) synthesized via a simple, cost-effective hydrothermal method. Moreover, the chemical attachment of Cu2+/Cu-0 nanoparticles on the surface of SPION@L-proline was done by an in-situ deposition method. The developed nano-photocatalyst was characterized in detail by XRD, FT-IR, XPS, FE-SEM, TEM, EDX, BET, TGA, and VSM. XRD of SPION@L-proline-Cu reveals peaks of both SPION and copper nanoparticles which confirms the formation of nanophotocatalyst. TGA demonstrates a major weight loss between 250 and 310 degrees C due to L-proline which ensures the successful immobilization of SPION on the surface of L-proline. The band energy at 932 eV suggests a complete reduction of Cu2+ ion to Cu-0 metal on the surface of SPION@L-proline nanocomposite as confirmed by the XPS technique. Under UV light irradiation, the photocatalytic reduction performance of the developed Cu2+ metal ion-based and Cu-0 nanoparticle-based magnetic nano-photocatalysts was demonstrated and compared for the first time for the photocatalytic reduction of 4-NP, 4-NA, NB, MO, MB, and CR. The results show that Cu-0-based magnetic nanophotocatalyst has slightly enhanced catalytic activity. Furthermore, solar-driven photocatalytic degradation of CR azo dye by synthesized nano-photocatalyst was also investigated, with a 95 % degradation efficiency in just 40 min. The developed magnetic nano-photocatalyst can easily be separated by using an external magnet due to the superparamagnetic nature of core material (SPION) at room temperature as confirmed from VSM and can be reused for multiple cycles without losing considerable catalytic activity. Because of its high photocatalytic efficiency, cost-effectiveness, good magnetic separation performance, non-toxicity, and strong thermal and chemical stabilities, Cu2+/Cu-0-based magnetic nano-photocatalyst has potential application in wastewater treatment.

Automated summary

This work successfully functionalizes L-proline on the surface of superparamagnetic iron oxide nanoparticles (SPION) via a simple hydrothermal method, and further attaches Cu2+/Cu-0 nanoparticles onto the surface of SPION@L-proline by an in-situ deposition method. The developed nano-photocatalyst is characterized in detail, confirming its structure and performance. The Cu-0-based magnetic nano-photocatalyst shows slightly enhanced catalytic activity and demonstrates efficient photocatalytic degradation of dyes under solar irradiation. The superparamagnetic properties enable easy separation and recyclability of the nano-photocatalyst. The Cu2+/Cu-0-based magnetic nano-photocatalyst has potential applications in wastewater treatment due to its high photocatalytic efficiency, cost-effectiveness, magnetic separation performance, non-toxicity, and thermal and chemical stabilities.