Impinging Stream–Rotating Packed‐Bed Reactor Combination Coprecipitation Synthesis of Cobalt–Manganese‐Layered Double Hydroxide for Electrode Materials

Zhang, Ning; Ren, Xiaojing; Guo, Yujin; Liu, Zhiwei; Liu, Youzhi

doi:10.1002/ente.201900156

Cited by 10 publications

(8 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Regarding XRD data, impurities were observed in many cases, while the purest reported Co R Mn-LDH phases display a poor crystallinity. 31,36,37,54,59 So far, no investigation has been done on Co R Mn-LDH chemistry and structure while applications for such layered materials have been emerging.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Coatings of Co R Mn-LDH thin films on scaffolders (i.e., Ni foam, , carbon fibers, carbon cloth, or activated carbon) were better obtained by the nucleation/crystal growth separation method using urea as the base-retardant agent. Regarding XRD data, impurities were observed in many cases, while the purest reported Co R Mn-LDH phases display a poor crystallinity. ,,,, So far, no investigation has been done on Co R Mn-LDH chemistry and structure while applications for such layered materials have been emerging.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Insights into the Structure and the Electrochemical Reactivity of Cobalt-Manganese Layered Double Hydroxides: Application to H₂O₂ Sensing

et al. 2020

View full text Add to dashboard Cite

A series of Co R Mn-LDH (R = 1, 2, 3, 4, 5) was synthesized by the coprecipitation method. The formation of layered double hydroxides (LDH) phases is confirmed by powder X-ray diffraction (XRD) and infrared spectroscopy (FTIR). The energy dispersive X-ray analysis (EDX) shows the total coprecipitation of Co and Mn. The X-ray photoelectron spectroscopy (XPS) gives evidence of the joint presence of Co(II), Co(III) and Mn(III) in the LDH structures in proportion depending on the initial R value. The Rietveld refinement of the structure using the XRD data reveals that the sample with a CoMn ratio 3:1 displays a pure LDH phase containing mainly Co(II) and Mn(III) with a M(II)/M(III) of nearly 2.1, in agreement with the X-ray absorption spectroscopy (XAS) results at the Co and Mn K-edges, strong hydrogen bonding network involving CO 3 2-/OHcharge compensating anions in the interlayers. When compared with the other Co R Mn-LDH, the Co 3 Mn-LDH displays the best redox properties in an alkaline medium (0.1 M NaOH) and in a neutral pH (Tris buffer). An indepth study of the Co 3 Mn-LDH obtained after electrochemical oxidation was also performed. The evolution of Co and Mn oxidation state under electrochemical oxidation were evidenced by XPS. Finally, the performance of the Co 3 Mn-LDH modified electrode was determined for the electrocatalytic detection of hydrogen peroxide.

show abstract

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Insights into the Structure and the Electrochemical Reactivity of Cobalt-Manganese Layered Double Hydroxides: Application to H₂O₂ Sensing

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Recently, many researchers have attempted to synthesize LDH nanoparticles in a high-gravity environment, but most of them did not achieve particles in the nanoscale (≤100 nm). For example, an impinging stream–rotating packed-bed (IS-RPB) reactor was used with a coprecipitation method to prepare CoMn-LDH by Zhang et al According to their results of scanning electron microscope (SEM) and dynamic light-scattering, the particles were obtained with an average particle size of 187.9 nm. Similarly, Xu and co-workers prepared MgAl-LDHs using a high-gravity-reactive precipitation method, but the particles were obtained with an average particle size of 160 nm and a broad size distribution ranges from 46 to 478 nm .…”

Section: Introductionmentioning

confidence: 99%

High-Gravity-Assisted Synthesis of Surfactant-Free Transparent Dispersions of Monodispersed MgAl-LDH Nanoparticles

Chen

Sun

Wang

et al. 2020

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

As a family of important inorganic layered materials, layered double hydroxides (LDHs) have attracted considerable attention owing to their potential applications in wide areas. Generally, the size, shape, uniformity, and dispersity of LDHs have great effects on their application properties. Herein, we report an efficient approach to prepare surfactant-free transparent dispersions of monodispersed CO 3 2− -intercalated MgAl-LDH nanoparticles using a high-gravity-assisted intensified coprecipitation method in a rotating packed-bed (RPB) reactor, followed by hydrothermal treatment. After a rapid coprecipitation in the RPB reactor, monodispersed MgAl-LDH nanoparticles with an average particle size of about 31 nm can be obtained. As compared to that in a stirred tank reactor (STR), the product from the RPB has a much smaller particle size, narrower size distribution, and higher optical transparency. More importantly, the reaction time can be significantly reduced from 20 min to 20 s, realizing an efficient continuous preparation. Subsequent hydrothermal treatment will facilitate the particles to change from irregular shapes to hexagonal nanoflakes. Simultaneously, the average particle size of MgAl-LDH nanoparticles rises to 65−72 nm on increasing the hydrothermal temperature from 90 to 130 °C. Furthermore, highly transparent and flexible nanocomposite films consisting of poly(vinyl alcohol) (PVA) and MgAl-LDH nanoparticles are readily fabricated with the spin-coating method and the layer-by-layer technique. It could be envisioned that such LDH dispersions may have a wide range of potential applications in the fields of optical devices, catalysis, gas separation, sensing, and antiflaming materials.

show abstract

“…The diffraction peaks are well matched with the previously reported literature. 4,8,23 That is, the observed CoMn-LDH characteristic peaks were found to match Co(OH) 2 (JCPDS: 51-1731) and Mn(OH) 2 (JCPDS: 18-0787). Furthermore, the presence of the characteristic peaks (006 facet) in the XRD pattern confirmed the successful formation of layered reflection peaks of the CoMn-LDH.…”

Section: Resultsmentioning

confidence: 79%

“…7 Compared to the other methods such as electrodeposition and hydrothermal, the CoMn-LDH electrode material prepared by a novel impinging stream-rotating packed-bed reactor produced the maximum specific capacitance of 1477 F/g at 1 A/g with a retention of 70% of its capacitance (5 A/ g). 8 The electrodeposited CoMn-LDH with the 9:1 M ratio of cobalt and manganese displayed a specific capacitance of 1062.6 F/g (0.7 A/g). The practical approach fabrication of asymmetric supercapacitor (ASC) showed 2500 W/kg of power density and 4.4 Wh/kg of energy density.…”

Section: Introductionmentioning

confidence: 98%

A redox‐additive electrolyte for cobalt‐manganese‐layered double hydroxides‐based asymmetric supercapacitor

Vijaya

Sharma

Aljafari

et al. 2022

Intl J of Energy Research

View full text Add to dashboard Cite

A cobalt-manganese-layered double hydroxide (CoMn-LDH), the extremely desired electrode material in supercapacitors, has been synthesized via a onestep hydrothermal technique. The XRD analysis confirmed the formation of the CoMn-LDH. The nanorod-shaped surface morphology is revealed from the scanning electron microscopy and transmission electron microscopy analysis. The asymmetric supercapacitor has been constructed by employing activated carbon as anode material and CoMn-LDH as cathode material. The electrodes have been investigated in the mixed electrolyte comprised of potassium hydroxide and potassium ferricyanide. The fabricated supercapacitor with the two-electrode system delivers the highest specific capacitance of 30 F/g at 1 mA along with the highest energy and power density of 6 Wh/kg and 1400 W/kg. Furthermore, the electrodes demonstrate high capacity retention of 81.25% at a high current density of 5 mA after 1000 cycles.

show abstract

Impinging Stream–Rotating Packed‐Bed Reactor Combination Coprecipitation Synthesis of Cobalt–Manganese‐Layered Double Hydroxide for Electrode Materials

Cited by 10 publications

References 40 publications

Insights into the Structure and the Electrochemical Reactivity of Cobalt-Manganese Layered Double Hydroxides: Application to H₂O₂ Sensing

Insights into the Structure and the Electrochemical Reactivity of Cobalt-Manganese Layered Double Hydroxides: Application to H₂O₂ Sensing

High-Gravity-Assisted Synthesis of Surfactant-Free Transparent Dispersions of Monodispersed MgAl-LDH Nanoparticles

A redox‐additive electrolyte for cobalt‐manganese‐layered double hydroxides‐based asymmetric supercapacitor

Contact Info

Product

Resources

About

Impinging Stream–Rotating Packed‐Bed Reactor Combination Coprecipitation Synthesis of Cobalt–Manganese‐Layered Double Hydroxide for Electrode Materials

Cited by 10 publications

References 40 publications

Insights into the Structure and the Electrochemical Reactivity of Cobalt-Manganese Layered Double Hydroxides: Application to H2O2 Sensing

Insights into the Structure and the Electrochemical Reactivity of Cobalt-Manganese Layered Double Hydroxides: Application to H2O2 Sensing

High-Gravity-Assisted Synthesis of Surfactant-Free Transparent Dispersions of Monodispersed MgAl-LDH Nanoparticles

A redox‐additive electrolyte for cobalt‐manganese‐layered double hydroxides‐based asymmetric supercapacitor

Contact Info

Product

Resources

About

Insights into the Structure and the Electrochemical Reactivity of Cobalt-Manganese Layered Double Hydroxides: Application to H₂O₂ Sensing

Insights into the Structure and the Electrochemical Reactivity of Cobalt-Manganese Layered Double Hydroxides: Application to H₂O₂ Sensing