D4 x ray diffractometer

XRD (X-ray diffraction) curves were obtained using a Bruker D4 X-ray diffractometer (Bruker, Baltimore, MD, USA, Cu Ka radiation). SEM (scanning electron microscope) images were obtained using a Hitachi S-4800 microscope (Hitachi, Tokyo, Japan). N₂ adsorption/desorption experiment was conducted on a Nova l000 analyzer (Quantachrome, Boynton Beach, FL, USA) at 77 K. Before the measurements, the samples were placed in vacuum at 100 °C for 5 h. Porous parameters of all the samples, such as surface area, pore volume, and pore size distribution, were determined by BET (Brunauer–Emmett–Teller) and BJH (Barrett–Joyner–Halenda) methods. Optical measurements, such as of absorption and emission spectra, were acquired using a Shimadzu UV-3101 spectrophotometer (Shimadzu, Tokyo, Japan) and a Hitachi F-4500 fluorescence spectrophotometer (λ_ex = 980 nm, Hitachi, Tokyo, Japan).

XRD data were collected a D4 X-ray diffractometer (Bruker, Germany) equipped with CuKα radiation (λ = 0.154 nm). Scanning electron microscope (SEM) measurements were conducted on TESCAN VEGA3. Zeta potential was determined by Zetasizer Nano ZS90 with (Malvern Co., UK). Samples were prepared by preparing rGO dispersions in 0.01 M salt solutions containing LiCl, MgCl₂ and ZnCl₂. All the samples present similar pH at around 6 as tested by pH paper. Zeta potential was carried out every 10 measurements for each sample and every 20 times scan for each measurement. The mean value and distribution as indicated by the phase plot are good, then we present the mean value among 10 times measurements with error bars. The in-situ displacement of electrode was measured by an ECD-3-nano electrochemical dilatometer, the dilatometer was placed inside an oven with fixed temperature at 25 °C during the whole measurement. TPD-MS measurement was conducted under the Ar atmosphere 75 mL min⁻¹. rGO powder was placed in a thermo-balance and heat up to 900 °C at a heating rate of 10 °C min⁻¹. The resulted decomposition products were monitored by online mass spectrometry (Skimmer, Netzsch, Germany).

AgNPs were synthesized by laser ablation from an Ag target (99.9% purity) in deionized water. The light source was an Nd:YAG pulsed laser with 1064 nm wavelength, 300 mJ energy per pulse, spot size of 3 mm², fluence of about 10 J/cm² and 5 ns pulse duration. The laser beam was focused normal to the target placed inside the 80 cc deionized water. The ablation proceeded for 40 min with 10 Hz repetition rate. Using inductively coupled plasma (ICP) analysis, the Ag concentration was obtained to be ≈15 ppm. Optical properties were measured in the 190–1100 nm range using a Lambda 25 spectrophotometer (Perkin Elmer). XRD was carried out using a Bruker D4 X-ray diffractometer. The Cu K (0.154 nm) X-ray line was used as the probe beam. The absorption spectrum of AgNPs (Fig. 1(a)) represents the characteristic plasmon absorption around 400 nm, characteristics of AgNPs with a beige color. Figure 1(b) shows the XRD pattern of AgNPs which indicates particles have crystalline structure. Figure 1(c) represents a typical TEM images of particles. From this image, the average particle size was estimated to be 2.4 nm.Figure 1

(a) Optical absorption spectrum, (b) XRD pattern and (c) TEM image of AgNPs.

However, instead of estimating the average NP-sizes, a proper size characterization should also be done in suspension, e.g. by using dynamic light scattering (DLS).

Transmission electron microscopy (TEM), scanning TEM (STEM), high-resolution TEM (HRTEM), and energy-dispersive X-ray spectroscopy (EDS) and elemental mapping were performed on a Tecnai G2 20 TWIN microscope operated at 200 kV. Field-emission scanning electron microscopy (FESEM) images were collected on a Zeiss Ultra-55 microscope operated at 5 kV. Small-angle X-ray scattering (SAXS) was performed on a Nanostar U small angle X-ray scattering system using Cu Ka radiation (40 kV, 35 mA). Powder X-ray diffraction (XRD) was conducted on a Bruker D4 X-ray diffractometer. Fourier-transform infrared (FTIR) spectra were acquired using a PerkinElmer Spectrum Two spectrometer with a scanning range from 4,000 to 400 cm⁻¹. Nitrogen adsorption–desorption isotherms were recorded on a Tristar 3000 instrument. Raman spectra were measured on an XploRA Raman system at room temperature. Thermogravimetric analysis (TGA) measurements were carried out on a Perkin–Elmer Pyris 1 thermogravimetric analyzer.

X-ray diffraction (XRD) patterns were collected by using a BrukerD4 X-ray diffractometer (Bruker, Germany) with Ni-filtered Cu Kα radiation (40 kV, 40 mA). Field emission scanning electron microscopy (FE-SEM) was performed on a FE-SEM-4800-1. Prior to the FESEM analyses, a thin layer of Au was sputtered on the surfaces of the as-prepared materials. Transmission electron microscopy (TEM) was performed by using a JEOL JEM-2010 transmission electron microscope (JEOL, Japan) operated at 200 kV. X-ray photoelectron spectroscopy (XPS) was performed by using a PHI5300 X-ray photoelectron spectroscope (Perki-Elmer, America) with aluminum target (14 kV, 250 W). Thermogravimetric-mass spectrum test was performed on SDT Q600 (USA) – GSD 301 T2 (Germany) combined system under nitrogen flow.

Transmission electron microscopy (TEM) images were taken with a JEOL 2011 microscope (Japan) at 200 kV. Fourier transform infrared (FT-IR) spectra were collected on a Nicolet Nexus 470 Fourier spectrophotometer (USA) using KBr pellets. The nitrogen sorption isotherms, pore size distribution and Brunauer–Emmett–Teller (BET) surface area were measured at 250 °C with a Micromeritics TriStar 3000 analyzer (USA). Powder X-ray diffraction (XRD) measurements were performed with a Bruker D4 X-ray diffractometer with Ni-filtered Cu Kα radiation (40 kV, 40 mA). For all of the chemicals and reagents, an AB204-N analytical balance (Mettler Toledo, Switzerland) was used for weighing. Stirring was performed by an HD2004W constant speed mechanical stirrer (Sile, China).