Figure 2b,c shows the high-resolution TEM images for Ni-NiO/PDDA-G. The different contrasts are shown: Ni (dark) and NiO (bright) nanoparticles. Both particle sizes are around 2 to 5 nm. Selected area electron diffraction (SAED) patterns 4SC-202 order for the Ni and NiO are shown in Figure 2d. The brighter and bigger spots are for the Ni nanoparticle electron diffraction patterns. The results of EDS mapping from the STEM method are shown in Figure 2e. The Ni and O elements are colored red and blue to show the
contribution for Ni-NiO nanoparticles on PDDA-G. The more condensed Ni element mapping is showing that the Ni-NiO nanoparticles exist. By EDS, the semi-quantified element ratios are Ni 15.1% and O 26.8% by weight (Ni 3.83% and O 24.7% by mole). The one-step synthesis with hydrothermal method is perfect for the synthesis process for the narrow size distribution of nanoparticles.TGA shows that the loading
content of the Ni-NiO nanoparticles is about 34.84 wt% on the PDDA-G surfaces. The TGA result is shown in the Figure 3a. For comparison with the other metal loading contents by hydrothermal method, the Au/PDDA-G and PtAu/PDDA-G are observed in the Figure 3b. The same precursor loading (approximately 0.456 mmol) with the same batch PDDA-G was applied in the one-pot synthesis method. The nickel reduction rate is obviously lower than the reduction rate of NVP-LDE225 gold and Selleckchem Proteasome inhibitor platinum by the metal loading amounts, which is in the order of 34.82, 58.2, and 74.1 wt%. Figure 1 XRD patterns of Ni-NiO/PDDA-G nanohybrids. Figure 2 TEM images and SAED pattern of Ni-NiO/PDDA-G nanohybrids. (a) The low-magnification image of Ni-NiO/PDDA-G.
(b) The high-magnification image of Ni-NiO/PDDA-G. (c) The high-resolution image of Ni-NiO/PDDA-G. (d) The SAED pattern of Non-specific serine/threonine protein kinase Ni-NiO/PDDA-G. (e) From left to right: STEM image, Ni element EDS mapping, O element EDS mapping, and the EDS spectrum of STEM-EDS mapping for Ni-NiO/PDDA-G, respectively. Figure 3 TGA result of Ni-NiO/PDDA-G nanohybrids. (a) Ni-NiO/PDDA-G. (b) The PtAu/PDDA-G and Au/PDDA-G. PDDA was used to modify the surface of graphene, and then the Ni-NiO nanoparticles could be embedded on the PDDA-G surface. The change of functional groups in the Ni-NiO/PDDA-G would be evaluated by ESCA/XPS in Figure 4a. The C1s binding energy of the C-C sp2 (284.6 eV, 72.4%) and that of epoxy group (286.7 eV, 27.6%) are shown, respectively. The binding energy of O1s was fitted as 531.2 eV (C-O-Ni, 18.9%), 532.1 eV (C = O/O-Ni, 26.4%), 533.5 eV (C-OH/C-O-C, 30.0%), and 535.0 eV (COOH, 24.7), respectively. The N1s spectrum was fitted as 399.4 eV (binding PDDA, 54.4%) and 400.6 eV (free PDDA, 45.5%). Furthermore, the curve fitting of Ni2p spectrum results in Figure 4b shows Ni0 (the binding energies for 857.1 and 875.