2.2.3. X-ray Diffraction Spectroscopy

The crystal structure and size of the synthesized ZnNMs were obtained through Xray diffraction spectroscopy analysis. The X-ray diffraction patterns for the six different ZnNMs were obtained on X-ray diffractometer (Bruker D8 Advance, Germany) using Cu (Kα λ = 0.150595 nm) radiations at specific operation conditions (voltage: 40 kV, current: 30 mA). The samples were scanned with a scanning angle (2θ) range of 5◦ to 80◦ and a step size of 0.02◦ respectively.

### 2.2.4. Fourier Transform Infra-Red Spectroscopy

The FT-IR spectroscopy (Thermo Nicolet 6700, USA) equipped with DTGS (deuterated triglycine sulfate) detector and KBr beam splitter system was used to characterize and identify the functional group diversity of the prepared nanoparticles. The summation spectra were generated in transmittance mode by placing dry, homogenized ZnNMs powdered samples on zinc selenide (flatbed configuration) crystal of the Attenuated total reflection (ATR) (Smart assembly, Thermo Fischer, USA) assembly with operational parameters of 32 scans at 4.0 cm−<sup>1</sup> spectral resolution and acquired for the mid-IR region spanning over 4000 to 600 cm−<sup>1</sup> .
