Representative TEM micrographs for Pd/SiO2 samples reduced by polyethylene glycol (PEG) at different time intervals after reaching 180 °C: (a) 0 min; (b) 15 min; (c) 30 min; (d) 45 min; (e) 60 min; (f) 90 min; (g) 120 min; and (h) 120 min, after cooling. 

Representative TEM micrographs for Pd/SiO2 samples reduced by polyethylene glycol (PEG) at different time intervals after reaching 180 °C: (a) 0 min; (b) 15 min; (c) 30 min; (d) 45 min; (e) 60 min; (f) 90 min; (g) 120 min; and (h) 120 min, after cooling. 

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The size and shape distribution of metal nanoparticles (NPs) are important parameters that need to be tuned in order to achieve desired properties of materials for practical applications. In the current work, we present the synthesis of palladium NPs supported on silica by three different methods, applying reduction by sodium borohydride, hydrazine...

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... quantitative results of TEM size distribution analysis for these three samples are summarized in Table 1. When PEG was used as a reduction agent, the slow formation of the SiO2 decorated with ultra- small palladium NPs was observed (Figure 2). It should be noted that 90 min after the start of the reaction, there were no significant changes in the morphology of the NPs. ...

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... [6,15,28] However, NaBH 4 is considered as a force reducing agent which can reduce metallic ions at room temperature, and the disadvantage of NaBH 4 process is the formation of irregular particle size. [29][30][31][32][33] As a consequence, the combination process of ethylene glycol (EG) and NaBH 4 can get better reduction to prepare the nanoparticles. ...
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... Palladium is well-known for its ability for dissociative adsorption and storage of hydrogen [1]. The hydrogen storage capacity and kinetics of hydrogen adsorption and desorption are strongly affected by the particle's size and shape [2][3][4][5][6][7][8], which is an important parameter for catalytic applications [8][9][10][11][12][13][14]. Bulk palladium materials exhibit a sharp phase transition from αto β-hydride, resulting in a characteristic plateau in the pressure composition isotherm [1]. ...
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... However, studies on the changes in the electrochemical properties of ZrO 2 NPs after the inclusion of graphene are rarely reported. The size of the NPs and surface chemistry play important roles in defining the electrochemical properties of materials [25]. Particularly, the size of NPs is an important factor in defining their electronic and optical properties. ...
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A single-step solvothermal approach to prepare stabilized cubic zirconia (ZrO2) nanoparticles (NPs) and highly reduced graphene oxide (HRG) and ZrO2 nanocomposite (HRG@ZrO2) using benzyl alcohol as a solvent and stabilizing ligand is presented. The as-prepared ZrO2 NPs and the HRG@ZrO2 nanocomposite were characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD), which confirmed the formation of ultra-small, cubic phase ZrO2 NPs with particle sizes of ~2 nm in both reactions. Slight variation of reaction conditions, including temperature and amount of benzyl alcohol, significantly affected the size of resulting NPs. The presence of benzyl alcohol as a stabilizing agent on the surface of ZrO2 NPs was confirmed using various techniques such as ultraviolet-visible (UV-vis), Fourier-transform infrared (FT-IR), Raman and XPS spectroscopies and thermogravimetric analysis (TGA). Furthermore, a comparative electrochemical study of both as-prepared ZrO2 NPs and the HRG@ZrO2 nanocomposites is reported. The HRG@ZrO2 nanocomposite confirms electronic interactions between ZrO2 and HRG when compared their electrochemical studies with pure ZrO2 and HRG using cyclic voltammetry (CV).
... Samples were examined on a Bruker D2 Phaser X-ray diffractometer (Cu K α , λ � 1.5417Å) with a step of 0.02°. X-ray diffraction (XRD) patterns were analyzed by Jana2006 program [27], following the procedure elsewhere [28,29]. X-ray fluorescence (XRF) analysis was carried out on a two-dimensional micro-X-ray fluorescence spectrometer Bruker M4 Tornado. ...
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