Abstract:A facile method to prepare pristine nanoscale mayenite electride is presented. The highest achieved conductivity of melted sample was ~28 S cm−1, with 93% mass density.
“…G-band, 2D-band and D-band confirm the existence of carbon family and a very weak D band peak (1340 cm −1 ) emerges in spectra, shown defective layers 1,2,8,9 . As the peak intensity ratio I2D/IG is less than 1 and the FWHM of the 2D band peak is ~89 cm −1 , the obtained rGO should be the stacking of multilayer sheets 1,2 . Comparatively small D band peak than 2D band peak in the Raman spectrum could be ascribed to the excellent reduction of rGO during applied synthesis process, in which the oxygen moieties were removed and the sp 2 network was restored due to structural relaxation 2,8,9,34 .…”
Section: Resultsmentioning
confidence: 58%
“…In Fig. 3, EDS mapping of Sn-doped C12A7:e − shows all expected elements, Ca, Al, O, C and Sn in synthesized Sn-doped C12A7:e − sample 1,2,8,9 . Now for further application point of view we are going to discuss the measured electrical properties of synthesized material.Figure 3SEM images and EDX mapping of Sn-doped C12A7:e − composite sample synthesis at 1550 °C, where x = 1.…”
Section: Resultsmentioning
confidence: 99%
“…2. All peaks are corresponding to the well crystalline C12A7 phase (JCPDS, CAS number 48–1882) 1,2,8,9 .Figure 2XRD patterns of Sn-doped composite, where doping level, x = ( a ) 1, ( b ) 0.75, ( c ) 0.50, ( d ) 0.25, heated at 1550 °C. For comparison, the lines on the x-axis correspond to the peak positions for the pure C12A7.…”
Section: Resultsmentioning
confidence: 99%
“…That is because of the presence of carbon species which are in form of like rGO with slightly other graphitic materials properties, produced by thermal reduction of ethylene glycol. This acts as a template, which also makes this material stable at this high temperature 1,2,8,9 .…”
Novel approaches to synthesize efficient inorganic electride [Ca24Al28O64]4+(e−)4 (thereafter, C12A7:e−) at ambient pressure under nitrogen atmosphere, are actively sought out to reduce the cost of massive formation of nanosized powder as well as compact large size target production. It led to a new era in low cost industrial applications of this abundant material as Transparent Conducting Oxides (TCOs) and as a catalyst. Therefore, the present study about C12A7:e− electride is directed towards challenges of cation doping in C12A7:e− to enhance the conductivity and form target to deposit thin film. Our investigation for cation doping on structural and electrical properties of Sn- and Si-doped C12A7:e− (Si-C12A7:e, and Sn-C12A7:e−) reduced graphene oxide (rGO) composite shows the maximum achieved conductivities of 5.79 S·cm−1 and 1.75 S·cm−1 respectively. On the other hand when both samples melted, then rGO free Sn-C12A7:e− and Si-C12A7:e− were obtained, with conductivities ~280 S.cm−1 and 300 S·cm−1, respectively. Iodometry based measured electron concentration of rGO free Sn-C12A7:e− and Si-C12A7:e−, 3 inch electride targets were ~2.22 × 1021 cm−3, with relative 97 ± 0.5% density, and ~2.23 × 1021 cm−3 with relative 99 ± 0.5% density, respectively. Theoretical conductivity was already reported excluding any associated experimental support. Hence the above results manifested feasibility of this sol-gel method for different elements doping to further boost up the electrical properties.
“…G-band, 2D-band and D-band confirm the existence of carbon family and a very weak D band peak (1340 cm −1 ) emerges in spectra, shown defective layers 1,2,8,9 . As the peak intensity ratio I2D/IG is less than 1 and the FWHM of the 2D band peak is ~89 cm −1 , the obtained rGO should be the stacking of multilayer sheets 1,2 . Comparatively small D band peak than 2D band peak in the Raman spectrum could be ascribed to the excellent reduction of rGO during applied synthesis process, in which the oxygen moieties were removed and the sp 2 network was restored due to structural relaxation 2,8,9,34 .…”
Section: Resultsmentioning
confidence: 58%
“…In Fig. 3, EDS mapping of Sn-doped C12A7:e − shows all expected elements, Ca, Al, O, C and Sn in synthesized Sn-doped C12A7:e − sample 1,2,8,9 . Now for further application point of view we are going to discuss the measured electrical properties of synthesized material.Figure 3SEM images and EDX mapping of Sn-doped C12A7:e − composite sample synthesis at 1550 °C, where x = 1.…”
Section: Resultsmentioning
confidence: 99%
“…2. All peaks are corresponding to the well crystalline C12A7 phase (JCPDS, CAS number 48–1882) 1,2,8,9 .Figure 2XRD patterns of Sn-doped composite, where doping level, x = ( a ) 1, ( b ) 0.75, ( c ) 0.50, ( d ) 0.25, heated at 1550 °C. For comparison, the lines on the x-axis correspond to the peak positions for the pure C12A7.…”
Section: Resultsmentioning
confidence: 99%
“…That is because of the presence of carbon species which are in form of like rGO with slightly other graphitic materials properties, produced by thermal reduction of ethylene glycol. This acts as a template, which also makes this material stable at this high temperature 1,2,8,9 .…”
Novel approaches to synthesize efficient inorganic electride [Ca24Al28O64]4+(e−)4 (thereafter, C12A7:e−) at ambient pressure under nitrogen atmosphere, are actively sought out to reduce the cost of massive formation of nanosized powder as well as compact large size target production. It led to a new era in low cost industrial applications of this abundant material as Transparent Conducting Oxides (TCOs) and as a catalyst. Therefore, the present study about C12A7:e− electride is directed towards challenges of cation doping in C12A7:e− to enhance the conductivity and form target to deposit thin film. Our investigation for cation doping on structural and electrical properties of Sn- and Si-doped C12A7:e− (Si-C12A7:e, and Sn-C12A7:e−) reduced graphene oxide (rGO) composite shows the maximum achieved conductivities of 5.79 S·cm−1 and 1.75 S·cm−1 respectively. On the other hand when both samples melted, then rGO free Sn-C12A7:e− and Si-C12A7:e− were obtained, with conductivities ~280 S.cm−1 and 300 S·cm−1, respectively. Iodometry based measured electron concentration of rGO free Sn-C12A7:e− and Si-C12A7:e−, 3 inch electride targets were ~2.22 × 1021 cm−3, with relative 97 ± 0.5% density, and ~2.23 × 1021 cm−3 with relative 99 ± 0.5% density, respectively. Theoretical conductivity was already reported excluding any associated experimental support. Hence the above results manifested feasibility of this sol-gel method for different elements doping to further boost up the electrical properties.
“…Recently, the synthesis method involving solution phase is emerged as one of the most potential methods leading toward precise control of the shape, size, and structure of metal nanoparticles, which could serve as promising ORR electrocatalysts (Khan et al, 2018b,c,d). Previously, in our lab, we productively schemed and generated a suitable one-step facile solution-based method to synthesize C12A7:e − composite consisting of metal oxides and nitrogen-doped rGO materials (Khan et al, 2016, 2018a,b,c,d, 2019b; Zou et al, 2017). The synthesized composite has improved ORR performance to 0.1 M of KOH electrolytes for especially small-sized (~5-nm) nanoparticles with optimized crystalline structure and tuned electronic properties (Khan et al, 2018d).…”
For future pollution-free renewable energy production, platinum group metal (PGM)-free electrocatalysts are highly required for oxygen reduction reaction (ORR) to avoid all possible Fenton reactions and to make fuel cell more economical. Therefore, in this study, to overcome traditional electrocatalyst limitations, we applied facile method to synthesize robust mesoporous CrN-reduced graphene oxide (rGO) nanocomposite with MnO (thereafter, Cr/rGO composite with MnO) as an electrocatalyst by efficient one-step sol-gel method by ammonolysis at 900°C for 9 h. Synthesized porous structures of Cr/rGO nanocomposite with MnO have the highest estimated surface area of 379 m2·g−1, higher than that of the carbon black (216 m2·gcat-1) support, and almost uniform pore size distribution of about 4 nm. The Cr/rGO nanocomposites with MnO exhibit enhanced electrocatalytic ORR properties with estimated high half-wave potential of 0.89 V vs. the reversible hydrogen electrode (RHE) and current density of 5.90 mA·cm−2, compared with that of benchmark 20% Pt/C electrode (0.84 V, 5.50 mA·cm−2), with noticeable methanol tolerance and significantly enhanced stability in alkaline media. Hence, the Cr/rGO nanocomposites with MnO showed superior performance to 20 wt.% Pt/C; their half-wave potentials were 50 mV high, and the limiting current density was 0.40 mA·cm−2 high. In alkaline anion exchange membrane fuel cell (AAEMFC) setup, this cell delivers a power density of 309 mW·cm−2 for Cr/rGO nanocomposite with MnO, demonstrating its potential use for energy conversion applications. The nanosized Cr/rGO metallic crystalline nanocomposites with MnO gave a large active surface area owing to the presence of rGO, which also has an effect on the charge distribution and electronic states. Hence, it may be the reason that Cr/rGO nanocomposites with MnO, acting as more active and more stable catalytic materials, boosted the electrocatalytic properties. The synergistic consequence in nanosized Cr/rGO composite with MnO imparts the materials' high electron mobility and thus robust ORR activity in 0.1 M of KOH solution. This potential method is highly efficient for synthesis of large-scale, non-noble-metal-based electrocatalytic (NNME) materials (i.e., Cr/rGO nanocomposite with MnO) on the gram level and is efficient in preparing novel, low-cost, and more stable non-PGM catalysts for fuel cells.
The 2D graphene (G) nanosheets (NSs) discovery is amound the foremost revolutionary incidents in materials science history. This discovery has stimulated huge attention in the study of other novel 2D materials (2DMs). This trend might be called modern day "alchemy," where the basic aim is to convert most of periodic table elements into G like 2D structures. Monoelemental, atomically thin 2DMs, called "Xenes" ("X" = group (III-VI)A elements, "ene" suffix that indicates one atom thick 2D layer of atoms) which are a newly invented family among nanomaterials. The number of predicted and experimentally synthesized 2D Xene materials of group IVA, i.e., G's siblings, has gained attention in nanosize devices. Such materials involve buckle structures that have recently been experimentally fabricated. The 2D Xene materials analog to G offer exciting potential for novel sensing applications. The group IVA Xenes, in cooperation with their ligandfunctionalized derivatives, arrange in a honeycomb lattice analogous to G but through a changeable degree of buckling. Their electronic structure ranges from trivial insulators passing via semiconductors with tunable gaps, to semimetallic, depending on substrate, chemical functionalization, and strain. In this review, different potential synthesis methods for group IVA 2D Xenes are briefly presented. A brief overview of their properties obtained theoretically and experimentally is presented, and finally their potential sensing applications are discussed.
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