Ft ir spectrum bx 2

Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) spectroscopy was used to identify the functional groups of EOs and cellulose in respective powders. A Perkin Elmer Fourier transform infrared spectrophotometer (Perkin Elmer FTIR Spectrum BX II, Waltham, MA, USA) was used in attenuated total reflectance (ATR) mode and acquired at a spectral range of 4000–500 cm⁻¹ at a resolution of 4 cm⁻¹, for 32 cycles. Perkin Elmer spectrum IR version 10.6.1 software was used for the analysis.

All chemical reagents and solvents were obtained from commercial suppliers (Sigma-Aldrich (St. Louis, MO, USA), TCI-Europe (Zwijdrecht, Belgium) and Merck (Darmstadt, Germany)). The purity of the compounds was checked by TLC (silica gel 60 F254 aluminium plates (Merck, Darmstadt, Germany)) and visualized by UV light. The flash column chromatography was performed by silica gel Wakogel C-200 (Wako Chemical, Osaka, Japan). The melting points were defined in open capillaries by using MEL-TEMP equipment (Barnstead Thermolyne Corp, Dubuque, IA, USA). UV-VIS spectra were obtained by Lambda 25 UV-VIS (Perkin-Elmer, Waltham, MA, USA) spectrophotometer. IR spectra were recorded in KBr on a Perkin-Elmer spectrophotometer (FT-IR Spectrum BX II). NMR spectra were obtained with Bruker spectrometer (¹H - 400 MHz and ¹³C - 100 MHz) in d-chloroform or d₆-DMSO by using residual solvent signal as an internal standard. HRMS spectra were recorded by Dual-ESI Q-TOF 6520 (Agilent Technologies, Santa Clara, CA, USA) mass spectrometer.

Potassium hydroxide, zinc acetate dihydrate, sodium nitrate, sulphuric acid, hydrochloric acid, methyl alcohol, and ethyl alcohol were obtained from Merk India Ltd. (grade AR). High molecular weight deacetylated chitin (Chitosan powder (CS)), N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC hydrochloride), and NHS (N-hydroxysuccinimide) were purchased from Sisco Research Laboratories Pvt Ltd. (Mumbai, India) Graphene oxide nanosheet was purchased from Reinste Nano Ventures (Noida, India). Potassium dihydrogen phosphate (KH₂PO₄) and other chemicals used during the synthesis were obtained from Merck Ltd., SRL Pvt. Ltd. (Mumbai, India). Double distilled water was used during the synthesis process.
The synthesized nanomaterials were investigated by X-ray diffractometer (XRD) and Scanning Electron Microscope (SEM) for structural properties and Fourier Transform Infrared Spectroscopy (FTIR) to examine the surface of functional groups. The FTIR analysis was performed on FTIR spectroscopy (Perkin Elmer FTIR Spectrum, BX-II, USA). The XRD analysis was performed on X-ray diffractometer (Rigaku D/max 2200 PC, Japan) using Cu Kα radiation between 10–80° intervals. The surface morphology was investigated by field emission scanning electron microscopy (MIRA II LMH from TESCAN, with a resolution of 1.5 nm at 30 kV, Czech Republic).