The dataset provides morphological, crystallographic, and surface chemistry data. Morphology is assessed via Transmission Electron Microscopy (TEM), with particle size distribution measured at multiple magnifications (50kX, 100kX, 400kX), including average sizes and SDs. Specific surface area and band gaps are also reported. Crystallographic properties are characterized using X-ray Diffraction (XRD) capturing crystallinity percentage, amorphous phase content, average crystallite size, and specific crystal structures. Surface chemistry is analyzed via X-ray Photoelectron Spectroscopy (XPS), providing elemental composition, binding energies for electron transitions, and % atomic concentration.

Functionality dataset provides photocatalytic activity tests for NEPs, assessing the degradation of Nitrogen Oxide (NO) and nitrogen dioxide (NO₂) gases under visible light, measured via chemiluminescence. Key parameters recorded include irradiance (W/m²), temperature, and sample dimensions. NO degradation is quantified through initial NO concentration (ppbv) and exposure duration (min). TiO₂ deposition on PMMA substrates is quantified using ICP-OES, with measurements including TiO₂ mass (mg/m²), analysed area, PMMA weight (g/m²), sample weight and TiO₂ content per PMMA sample (mg). For textiles the TiO₂ concentration is expressed as mg Ti/g textile and wt%. This metadata includes measurements from 2 different partners, leading to apparent missing values due to differences in reporting metrics rather than actual data gaps