Raw characterisation data for washed and unwashed green-synthesised iron oxide from Cucurbita pepo leaf extract: XRD, TGA, Raman power series, FTIR, zeta potential and electron microscopy

This dataset contains the unprocessed instrument output supporting a study of iron oxide nanomaterials prepared by alkaline co-precipitation of Fe²⁺ and Fe³⁺ in the presence of Cucurbita pepo (field pumpkin) leaf extract. No file has been smoothed, background-subtracted, normalised or otherwise altered; all processing reported in the associated article was performed downstream of these files. Five samples are included, all derived from portions of a single synthesis batch and differing only in the number of post-synthesis wash cycles: two unwashed (B, C) and three washed with 2, 6 and 10 Milli-Q water cycles (BW, CW, AW respectively). Wash-cycle number is the only deliberately varied parameter, and the organic content of the product falls monotonically with it, from 60–66 % of the total mass in unwashed material to 2.4 % after ten cycles. The data comprise X-ray diffraction (PANalytical Empyrean, Cu Kα, 5 files), thermogravimetry (Shimadzu DTG-60H under nitrogen, 5 files), Raman spectroscopy (532 nm, 42 files, including a four-point laser-power series at 1, 2, 5 and 10 mW on three samples), infrared spectroscopy (10 files, including two leaf-extract controls), ultraviolet–visible spectroscopy (1 file), electrophoretic light scattering (2 files), 43 transmission electron micrographs with embedded pixel calibration, and 52 field-emission scanning electron micrographs. Documentation includes the botanical authentication certificate for the plant material, MD5 checksums for every file, and analysis notes recording the filter windows, thresholds and fitting choices used to derive the published quantities. The Raman power series may be of interest independently of the rest: it documents laser-induced oxidation of a spinel iron oxide occurring within the acquisition itself, and can be used to demonstrate why incident power must be reported when Raman spectroscopy is used for phase assignment in iron oxide systems. Several limitations are recorded in the README so that reusers are not misled. Raman powers are nominal settings rather than measured power at the sample; the ultraviolet–visible data are photometrically unusable and are included only for transparency; the diffraction patterns carry an uncorrected specimen-displacement offset; all samples derive from a single batch, so batch-to-batch reproducibility is not established; and several files relate to exploratory preparations whose provenance is not recorded. No EDX, magnetometry, dynamic light scattering, antibacterial or catalytic data exist for these samples.