Ni–Zn hydroxide-based bi-phase multiscale porous nanohybrids: physico-chemical properties

Abstract

In this investigation, we report the synthesis of novel homogeneous micro-mesoporous bi-phase nanohybrids based on Ni/Zn hydroxides using a simple and low-cost free-template urea-based hydrothermal process at two different growth temperatures (120 and 180 °C) for 6 h in two cases of precursor ratios (Ni:Zn = 1:1 and Ni:Zn = 1:2). The synthesized products have been characterized with different techniques such as XRD, FT-IR, FESEM, Raman, BET and XPS analysis to identify quantitatively and qualitatively their original physico-chemical properties. The obtained structural results show the formation of bi-hydroxide-based products: α * -Ni(OH) 2 •0.75 H 2 O with Zn 5 (CO 3 ) 2 (OH) 6 (case Ni:Zn = 1:1) or with Zn 4 (CO 3 )(OH) 6 •H 2 O (Ni:Zn = 1:2) which are also proven by FTIR and Raman analyses. However, the obtained 3D micro-meso-nanohybrids with different pore morphology have been demonstrated through the FESEM micrographs depending on the synthesis conditions. Moreover, these porous products have been subjected to textural studies with the BET results showcasing a porous morphology with a reasonable specific surface area (SSA) and pore volume in the range (70-150 m 2 /g) and (0.19-0.85 cm 3 /g), respectively. Also, a clear improvement in the BET SSA (two times the initial value) was obtained with increasing the growth temperature in the two cases (1:1 and 1:2). Consequently, we have successfully synthesized active mesoporous materials with interesting specific surface area and porosity (pore volume and size) which make them attractive materials for electrode applications especially in energy storage and biosensing.

Ni/Zn Layered Double Hydroxide (LDH) Micro/Nanosystems and Their Azorubine Adsorption Performance

“…Figure 3 shows the deconvolution of main asymmetric peaks (Ni2p, Z C1s, and O1s) of high-resolution core-level XPS spectra, using L/G fitting method consis with the literature data [36,43]. Ni2p and Zn2p show that the oxidation state of these ments is mainly based on ions, namely Ni 2+ (or Zn 2+ ) as in previously reported data, w will be very beneficial in our adsorption process [36,44].…”

“…To better understand the composition of the used nanohybrid based adsorbent as well as the existing functional groups that act on the adsorption mechanism, XPS analysis was performed. Figure 3 shows the deconvolution of main asymmetric peaks (Ni 2p , Zn 2p , C 1s , and O 1s ) of high-resolution core-level XPS spectra, using L/G fitting method consistent with the literature data [36,43]. Ni 2p and Zn 2p show that the oxidation state of these elements is mainly based on ions, namely Ni 2+ (or Zn 2+ ) as in previously reported data, which will be very beneficial in our adsorption process [36,44].…”

“…Table 1 summarizes the bi-phase nanohybrid structural characteristics depending to their diffractogram. The FTIR spectrum of this nanoadsorbent as shown in Figure 1b is typical of a hydrotalcite-like material showing a broad and intense band at 3336 cm -1 thatcan be attributed to hydroxyl (OH − ) stretching vibrations from structural hydroxyl groups and interlayer water molecules [36]. In addition, bands at 1362 cm −1 (υ 3 ), 1043 cm −1 (υ 1 ) and 745 cm −1 (υ 2 ) [37] show the presence of carbonate anion (CO 3 2-) in the interlayer [38].…”

Electrochemical Measurements of Ni / Graphene based Nanohybrids for Electrochemical Energy Storage “Supercapacitors”

“…Firstly, we can clearly observe in the case of 6h/120°C (pure Ni mono-hydroxide), a formation of quasi micro-nanospheres at 3D with a porous texture and with well dispersed porosity due to an organized assembly of nano-needles (Fig. 4 a) [47]. These quasi micronanospheres with a porous texture have diameters around 2.5 μm.…”

An Extrinsic Faradaic Layer on CuSn for High-Performance Electrocatalytic CO 2 Reduction

“…As a reference sample, CuSn was also prepared by the same method. Figure 1a Zn 2+ and lattice OH -, respectively 29,30 . In order to further analyze the compositions of the two samples, element distributions of CuSn and CuSn/Zn(OH)x were examined by EDX-mapping (see Figure 1e, f and Figure S5).…”