Zen3690

Transmission electron microscopy (TEM) overview images were taken at 200 kV through Philips CM 200 electron microscope and analyzed through the software of ImageJ. The atomic and weight fraction of elements existing in the as-prepared materials was taken via energy-dispersive X-ray (EDX) spectroscopy. High-resolution X-ray photoelectron spectroscopy (XPS) spectra were obtained on a Kratos AXIS UltraDLD ultrahigh vacuum (UHV) surface analysis system. Powder UV–vis-NIR absorption spectra were collected with a PerkinElmer Lambda 750 UV–vis-NIR spectrophotometer. Photoluminescence (PL) measurements were performed with a Horiba Jobin–Yvon Fluoromax-4 spectrofluorometer. Fourier transform infrared spectrometer (FTIR) spectra were conducted with a Bruker Hyperion FTIR spectrometer and cumulated scans at a resolution of 4 cm⁻¹. The dynamic light scattering (DLS) and zeta potential of materials were detected using Malvern ZEN3690.

Zeta potential is used to measure the stability and surface charge of the suspension. The cellulose nanofibres solution of 0.03% w/v was prepared and sonicated to make the solution homogenous. Around 1 ml of a sonicated solution of CNF was transferred into a polystyrene macro-cuvette. Zeta potential was measured using a dynamic light scattering instrument (DLS, Malvern instrument, Zen 3690, UK). The measurements were taken in triplicate^{29 (link)}.

TiO₂, Cu_xO, and TiO₂–Cu_xO samples were characterized under different final conditions. The pristine TiO₂ and TiO₂–Cu_xO samples were annealed at 500 °C, and the pristine Cu_xO samples were as deposited. Scanning electron microscopy (SEM; S-5200, Hitachi High Technologies, Tokyo, Japan) was performed to examine the surface morphology of the nanoparticulate thin films. Transmission electron microscopy with energy dispersive X-ray spectroscopy (TEM-EDS; JEM-2010, JEOL, Tokyo, Japan) was conducted to observe the nanoparticle’s morphology and the elements within the film.
The crystallinity was confirmed using X-ray diffraction (XRD; MiniFlex 600, Rigaku, Tokyo, Japan) over the 2θ range of 20–60°, with Cu Kα (λ = 0.154 nm) radiation, an accelerating voltage of 40 kV, and a current of 15 mA. The chemical states were determined using X-ray photoelectron spectroscopy (XPS; ESCA-3400, Shimadzu Corp., Kyoto, Japan). Additionally, the reflectance was measured by UV–vis diffuse reflectance spectroscopy (UV-Vis DRS, V-650, Jasco, Tokyo, Japan). Zeta potential measurements (ZEN3690, Malvern Instruments Ltd., Malvern, UK) were also conducted.

MIL-53(Fe) was dissolved in methanol to obtain a 5 mg/L solution. FBS was diluted with PBS before testing. A 0.2 mL portion of the diluted solution of MIL-53(Fe) was added to 4.8 mL of FBS (pre-warmed to 37 °C for 30 min prior to experiments). After being incubated at 37 °C for 0, 1, 2, 4, 8, 12, 24, 48 and 72 h, observe if there is a deposit at the bottom. Zeta potential was tested with a Zetasizer (ZEN3690, Malvern Instruments Ltd., Malvern, UK).

The morphology and structure were characterized by transmission electron microscopy (TEM, JEOL JEM-2100 F). The crystal structure was determined by X-ray diffraction (XRD, Rigaku D/max2500). The chemical state was analyzed by X-ray photoelectron spectroscopy (XPS, Thermo Escalab 250), and the binding energy of C 1 s peak at 284.8 eV was taken as an internal standard. Fourier transform infrared (FTIR) spectrum was recorded on Bruker Tensor-27 spectrometer. Ultraviolet-visible-infrared (UV-vis-NIR) absorption spectrum was scanned on Persee TU-1901 spectrometer. The metal element content was determined by inductively coupled plasma optical emission spectroscopy (ICP-OES, Varian 710ES). Hydrodynamic size and zeta potential were characterized by a particle size zeta potential analyzer (Malvern ZEN3690).

HRTEM (FEI Tecnai F20, acceleration voltage = 200 kV) and SEM (Apreo S Lovac) were used to characterize the nanoparticle morphology. Fluorescence spectra were measured using an FLS980 instrument (Edinburgh Instruments). A PerkinElmer Lambda 400 UV–vis–NIR spectrophotometer was used to measure the UV–vis spectra. The nanoparticle sizes and zeta potentials were measured using a Malvern Zetasizer (ZEN3690, Malvern, UK). The nanoparticle surface area and pore size were measured using a surface area and porosity analyzer (ASAP2050, Micromeritics Instrument Corp.). The nanoparticle elemental composition was measured using XPS (Thermo K‐alpha).