Model s 4800

Three different sizes of graphite nanoplates (Gr) were provided by Cabot Corp., Billerica, MA. The samples were manufactured to have primary particle dimensions of 20 μm lateral (Gr20), 5 μm lateral (Gr5), and < 2 μm lateral (Gr1). Carbon black (CB), ~15 nm diameter, was purchased commercially (Printex 90, Degussa- Heuls, Germany) to serve as a particle control. FESEM (Hitachi Model S-4800, Japan) was used to visualize and verify size of the particles in the dry powder form.

The electrochemical properties of the electrochromic electrodes were measured using cycle voltammetry (CV) (model PGSTAT30, Autolab, Utrecht, The Netherlands) in a three-compartment system containing the abovementioned electrodes as the working electrodes (IrO₂/ITO/glass and NiO/ITO/glass) and Ag/AgCl as the reference electrodes, and Pt foil as the counter electrodes. Sample 1–6 carried out electrochemical cycles in the 0.5-M LiClO₄-PC solution at −0.5 V to 2.0 V and a potential sweep rate of 100 mV/s. The optical transmittance spectra of the colored and the bleached states were obtained using an ultraviolet-visible (UV-Vis) spectrophotometer (model DH-2000-BAL, Ocean Optics, Dunedin, FL, USA) in a wavelength range from 300 nm to 1000 nm. The crystalline structure was characterized by a high-resolution X-ray diffractometer (HRXRD, Model D8, Bruker AXS, Billerica, MA, USA) equipped with a CuKα (λ = 0.154 nm) radiation source over a 2θ scan region of 20° to 70°. It is provided with the essential accuracy and precision to measure the broadening and the relative peak. The surface morphological properties were examined with a field emission scanning electron microscope (FE-SEM) (Model S4800, Hitachi, Tokyo, Japan) operated at 15 kV.

The precipitation precursor and its reduction product were characterized by field-emission scanning electron microscopy (FE-SEM; Model S-4800, Hitachi, Japan) and X-ray diffraction (XRD; Model D8 Focus, Bruker, Germany) using nickel-filtered CuKα as the incident radiation. The surface microstructure of the ceramic was observed on a desktop scanning electron microscope (SEM; Model EM-30plus, COXEM, Korea). Photoluminescence (PL)/photoluminescence excitation (PLE) spectrum, fluorescence lifetime, and quantum yield of the powder and ceramic were measured by transient fluorescence spectrophotometer (Model FLS 980, Edinburgh Instruments Ltd., Livingston, UK) using a 450 W xenon lamp as the excitation source. The X-ray excited luminescence (XEL) spectrum of the ceramic was measured using the photomultiplier tube working on a Zolix Omni-λ300 monochromator at a voltage of −900 V, while the X-ray tube copper target was operated at a voltage of 69 kV and a current of 3 mA.

A field emission scanning electron microscope (SEM; Model S4800, Hitachi, Tokyo, Japan) was used for SEM imaging of the patterned samples. Minimal beam voltage (1 keV) and current (<1 nA) were used for high-resolution imaging. At these conditions, SEM imaging of fabricated nanostructures was performed without deposition of any thin layers of a conducting film.

The CBAC powder was purchased from Guoqing Water Purification Material Co. Ltd. in China and employed as a sorbent for the following lead adsorption experiments. According to the National Standard of China for Activated Nutshell Carbon. Testing, the CBAC pore structure and pore size distribution were determined by ASAP 2020 (Micromeritics). The t-plot and Barrett–Joyner–Halenda (BJH) methods were used to calculate the microporosity and the mesoporosity of CBAC, respectively. Boehm titration method was applied in the characterization of the surface functional groups of CBAC (Boehm 1966 ). FT-IR spectroscopy was used to detect vibration frequency change in the CBAC. The spectra were collected by a NICOLET iS10 (Thermo Scientific) within the range 500–4000 cm⁻¹ using a KBr window. The structural morphology of CBAC surface was characterized via SEM (Model S-4800 Hitachi, Tokyo, Japan) observation.
The Pb(II) stock solution (1000 mg/L) was obtained by dissolving lead nitrate in distilled water. This stock solution was then diluted to those required concentrations and their pHs were adjusted to desired values with 0.1 or 1.0 mol/L of NaOH or HCl solution. All chemicals in this research were of analytical grade and were used as received without any further treatment.

The surface morphology of the silver-based nanocomposite hydrogels was observed by using Scanning Electron Microscopy (SEM, Hitachi, Japan, Model S-4800), the samples were cut into thin slices using a razor blade and placed on double-sided tape to coat the sample with platinum. Under backscatter (BSC) and secondary electron (SE) modes, the surface morphology of the samples was observed under SEM with different magnification. Besides, the Energy Dispersive X-Ray Spectroscopy (EDX) was operated during SEM testing to confirm the elements in hydrogels and the disperse situation of AgNPs in hydrogels.