An Eco-Friendly Approach for the Synthesis of Ni/NiO/g-C3N4 Nanocomposite Using <italic>Cleome Gynandra</italic> Leaf Extract for Biomedical and Photocatalytic Applications.

The (Ni/NiO)CG/g-C3N4 nanocomposite was green synthesized using <italic>Cleome gynandra</italic> via sol–gel method. The photocatalytic dye decomposition, antioxidant and antidiabetic activities of the nanocomposite were studied and compared with those of (Ni/NiO)CG and g-C3N4. The nanocomposite exhibited enhanced photocatalytic efficiency of 97% compared to (Ni/NiO)CG (63%) and g-C3N4 (80%) due to the synergistic effect between both the composite partners. The nanocomposite, (Ni/NiO)CG/g-C3N4 showed notable antioxidant activity in DPPH (IC50 of 41.76 ± 0.88μg/mL with 87.06% of inhibition at 500μg/mL) and ABTS (IC50 of 47.60 ± 0.81μg/mL with 88.40 % of inhibition at 500μg/mL) radical scavenging assays. The green synthesized nanocomposite also exhibited significant antidiabetic activity in α-amylase and α-glucosidase enzyme inhibition assays with the IC50 of 33.83 ± 0.53μg/mL and 49.94 ± 0.64μg/mL, respectively. The XRD and SEM analyses confirmed the nanocomposite formation of (Ni/NiO)CG/g-C3N4. The results showed that the green synthesized (Ni/NiO)CG/g-C3N4 has desirable dye degradation, antidiabetic and antioxidant properties. This paper presents the results of the remarkable photocatalytic dye decomposition, antidiabetic and antioxidant properties of the nanocomposite (Ni/NiO)CG/g-C3N4 synthesized via an eco-friendly greeny way using <italic>Cleome gynandra</italic> leaf extract which may be the first report of this kind utilizing this plant. [ABSTRACT FROM AUTHOR]