DOI: https://doi.org/10.36347/sjet.2026.v14i09.003

Pages: 484-497

Plant-assisted synthesis offers a lower-hazard route to zinc oxide (ZnO) nanomaterials, yet the amount of plant extract can simultaneously alter nucleation, crystal growth, surface passivation, aggregation, and optical response. In this study, ZnO powders were prepared by alkaline precipitation from zinc acetate using 0, 10, 15, 20, 25, and 30 mL of Aloe vera inner-leaf gel extract, followed by drying and calcination at 350 °C. The extract is interpreted principally as a phytochemical complexing, growth-regulating, and surface-capping medium rather than as a conventional reducing reagent for Zn(II). X-ray diffraction patterns were consistent with hexagonal wurtzite ZnO and did not show obvious additional crystalline phases within the reported scans. Among the concentration series, the 15 mL sample exhibited the highest reported (selected-peak) intensity (2067 a.u.), the lowest full width at half maximum (0.49327°), the largest Scherrer crystallite size (17.05 nm), and the lowest single-line microstrain estimate (0.00620), indicating the most ordered structure under the tested conditions. Fourier-transform infrared spectra contained Zn-O absorption in the approximately 448-600 cm⁻¹ region together with O-H, C-H, C-O, and carbonyl/amide-related bands consistent with residual Aloe-derived surface species. UV-visible absorption edges occurred in the near-UV region, while near-band-edge photoluminescence at 378-392 nm corresponded to photon energies of approximately 3.16-3.29 eV. By contrast, concentration-series Tauc intercepts of 5.6-6.2 eV were physically inconsistent with the absorption edges and photoluminescence and are therefore reported only as apparent values requiring recalculation from raw, baseline-corrected spectra. Overall, 15 mL provided the most balanced structural and surface response in the available dataset. Morphology, composition, colloidal stability, replicate synthesis, uncertainty analysis, and application-specific performance remain necessary bef