Facile green synthesis of nickel-ferrite-rGO (NiFe2O4/rGO) nanocomposites for efficient water purification under direct sunlight

Facile green synthesis of magnetically separable nickel-ferrite nanocomposites supported over reduced graphene oxide (NiFe2O4/rGO) using peppermint leaf extract as reducing agent is reported herein. The as-synthesized nanocomposites are magnetic in nature and can be used as fine photocatalysts. It is fascinating that the mix-ing of inert NiFe2O4 with GO nanosheet produces highly active photocatalyst after the reduction of GO to reduced graphene oxide (rGO). The nanocomposites have been well characterized using different analytical techniques. Morphological and structural studies have shown the formation of spherical NiFe2O4 nanocomposites with particle size 3-5 nm, regularly supported over the layers of rGO. The nanocomposites have actively participated in the photocatalytic degradation of different dyes under direct sunlight within a very limited time. Congo red and Malachite green are completely degraded in 18 mins, while Methylene blue and Methyl orange are completely degraded in 30 and 12 mins respectively. Moreover, study showed that 30 mgL-1 nanocomposite was sufficient to degrade all the dyes completely. However, depending on the Ni/Fe ratio, the photocatalytic activity has been varied. Recovery and reusability of the nanocomposites have been done very smoothly because of the magnetically separable behavior of the nanocomposites, which shows the efficiency of the catalysts up-to 4th cycle with very minimal loss in activity. This green strategy of the synthesis and utilization of magnetically separable NiFe2O4/rGO nanocomposites for the waste water purification is remarkable.

Automated summary

A facile green synthesis method for magnetically separable nickel-ferrite nanocomposites supported over reduced graphene oxide (NiFe2O4/rGO) using peppermint leaf extract as a reducing agent is reported. The as-synthesized nanocomposites exhibit magnetic properties and can serve as efficient photocatalysts. The nanocomposites have been well characterized, and their morphology and structure indicate the formation of spherical NiFe2O4 nanocomposites supported over rGO layers. These nanocomposites show active participation in the photocatalytic degradation of various dyes under direct sunlight, with complete degradation achieved in a short time. The recovery and reusability of the nanocomposites are also demonstrated, indicating the effectiveness of the catalysts.