Hierarchical porous carbon microrods composed of vertically aligned graphene-like nanosheets for Li-ion batteries

Abstract

†Electronic Supplementary Information (ESI) available: SEM image and XRD pattern of the MgO microrods; EDX spectrum of HPCM-900; SEM images of HPCM-800 and HPCM-700; the synthesis, SEM image, N2 sorption isotherms, and pore size distributions of HCS; the rate performances of HPCM-800 and HPCM-700 electrodes; the SEM image and rate performance of PUCN-900 electrode; Nyquist plots of the HPCM-900 and PUCN-900 electrodes; HPCM-900 and other graphene electrodes evaluated at high rate. SeePreventing the stacking of ultrathin 2D carbon nanostructures is a very important research theme in the field of energy storage. In this work, hierarchical porous carbon microrods composed of vertically aligned graphene-like nanosheets (HPCMs) are successfully fabricated via a facile Mg(OH)2-templating method. The unique structure of HPCMs is a desirable combination of 1D hierarchical structures, vertically aligned graphenes, and porous graphenes. With the hierarchical structure and pores, high specific surface area, large pore volume, and ideal charge transport and ion diffusion pathways, HPCMs are the potential candidates for high-performance electrode materials. When used as an anode for Li-ion batteries, the HPCMs electrode exhibits excellent capability (1150 mAhg -1 at 0.1 Ag -1 ), rate performance (246 mAhg -1 at 10 Ag -1 ), and cycling stability (833 mAhg -1 after 700 cycles at 1 Ag -1 ), which is superior to those of natural graphite and many graphenebased anodes.

Economizing Production of Diverse 2D Layered Metal Hydroxides for Efficient Overall Water Splitting

“…With increasing the reaction time, the layer of Ni(OH) 2 nanosheets became thicker, and inner MgO were continuously consumed until it completely disappear. In comparison to our previous report, such a growth process is remarkably similar to the transformation process from MgO to Mg(OH) 2 nanosheets in pure water (Figure e) . It is widely recognized that the hydrolysis of MgO in pure water can be described as Equations – .…”

“…As previously reported by Fen et al and Zheng et al, the hydrolysis of MgO nanoparticles in pure water can yield Mg(OH) 2 nanosheets (Figure ) . However, although the solubility product constant (Ksp) of Mg(OH) 2 is much higher than many other LMH (e.g., M = Ni, Fe, Co), the precipitation transformation reaction is not effective enough to convert Mg(OH) 2 nanosheets into 2D LMH nanosheets.…”

High Sulfur Loading in Hierarchical Porous Carbon Rods Constructed by Vertically Oriented Porous Graphene‐Like Nanosheets for Li‐S Batteries

“…Figure schematically illustrated the synthetic process for HPCR. Mg(OH) 2 hierarchical microrods composed of vertically oriented Mg(OH) 2 nanosheets were obtained by hydrolyzation of MgO microrods at room temperature (Step I), as developed in our recent work . These hierarchical microrods were further used as templates for the chemical vapor deposition (CVD) growth of graphene‐like nanosheets (Step II).…”

Porous Carbon Nanosheets Prepared from Plastic Wastes for Supercapacitors

“…24 For the specific synthetic process, sodium carbonate (Na 2 CO 3 ) solution was dropwise added to magnesium chloride (MgCl 2 ) solution under continuous stirring (Na 2 CO 3 and MgCl 2 with a 1:1 mol ratio). The precipitate magnesium carbonate (MgCO 3 ) was collected by centrifugation after stirring at room temperature for 4 h. MgO micorods were obtained by calcining MgCO 3 under air atmosphere at 500°C for 2 h.…”