Quad 5040

The crystal structure of the samples was characterized by an X-ray diffractometer operating with Cu Kα radiation (XRD, Bruker D8, Hamburg, Germany). Carbon-doped TiO₂ films were deposited on the flat quartz substrates and HDPE beads under the same conditions simultaneously, and XRD data were collected from flat quartz samples. Crystallite size was estimated by Topas software based on the Scherrer equation with Lorentzian convolution. The surface views of the carbon-doped TiO₂ were investigated by a scanning electron microscope (SEM, Hitachi S-3400 N, Tokyo, Japan) using a backscattered electron detector. In addition, elemental mapping was conducted using energy-dispersive X-ray spectroscopy (EDS, Bruker Quad 5040, Hamburg, Germany). Surface elemental analysis and elemental distribution profiles in carbon-doped TiO₂ films were measured by an X-ray photoelectron spectroscope (XPS, PHI 5000 Versaprobe, Chanhassen, MN, USA) using monochromated 1486.6 eV Al radiation, 12.5 W beam power, 50 μm beam size, and 45° measurement angle. XPS depth profile measurement was performed by iterating ion gun sputtering (4 kV Ar⁺ ions, 1 min sputtering time) and XPS spectra acquisition after each sputtering step. Sample charging was compensated by a dual-electron low-energy ion neutralization system and fixing the adventitious carbon C 1 s peak at 284.8 eV.

Surface views of CuO-coated mask fabric and bacteria grown on the glass substrates were investigated by scanning electron microscope (SEM, Hitachi S-3400 N, Tokyo, Japan) using a secondary electron detector. Elemental mapping of the middle mask layers with CuO nanoparticles was performed using energy-dispersive X-ray spectroscopy (EDS, Bruker Quad 5040, Hamburg, Germany). The crystal phase of the CuO was identified by an X-ray diffractometer (XRD, Bruker D8, Hamburg, Germany) operating with Cu Kα radiation in the 2θ range between 20° and 70°.

The failure studies, surface morphology, and chemical composition of the composite samples were evaluated by using the scanning electron microscope (S-3400N from Hitachi) with an energy dispersive X-ray spectrometer (Quad 5040 from Bruker, Billercia, MA, USA).