Hierarchical architectured MnCO 3 microdumbbells and lamellar structured MnCO 3 nanosheets were selectively synthesized by a facile reflux route. Hierarchical architectured MnCO 3 microdumbbells (approximately 0.5-1.5 μm in length and 0.3-0.9 μm in width) were composed of nanoparticles, while the lamellar structured MnCO 3 nanosheets had uniform length of approximately 400 nm. Both structures were employed as anode active materials in lithium ion batteries. Experimental results showed that the hierarchical architectured MnCO 3 microdumbbells exhibited superior electrochemical performances compared with the lamellar structured MnCO 3 nanosheets. At a current rate of 0.5 C, the reversible capacity of the hierarchical architectured MnCO 3 microdumbbell electrode after 100 cycles was 775 mA h g −1 , while the lamellar structured MnCO 3 nanosheets electrode was only 50 mA h g −1 after 100 cycles. The superior electrochemical behavior of hierarchical architectured MnCO 3 microdumbbell materials could be ascribed to the unique micro-nano assembly structure, simultaneously cushioning the volume change, maintaining the electrode integrity, and offering a short diffusion distance. CrystEngCommThis journal is

Here we demonstrate for the first time a water-based surfactant-free synthesis of three-dimensional porous Pd@Pt core-shell nanoflowers on graphene. The obtained Pd@Pt-graphene hybrids exhibited substantially enhanced electrocatalytic activity and stability relative to the commercial Pt/C catalyst originating from this exquisite nanoarchitecture for three-dimensional molecular accessibility and graphene-metal interaction.

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Polyethylene glycol (PEG) based graphene aerogel (GA) confined shaped-stabilized phase change materials (PCMs) are simply prepared by a one-step hydrothermal method. Three-dimensional GA inserted by PEG molecule chains, as a supporting material, obtained by reducing graphene oxide sheets, is used to keep their stabilized shape during a phase change process. The volume of GA is obviously expended after adding PEG, and only 9.8 wt% of GA make the composite achieve high energy efficiency without leakage during their phase change because of hydrogen bonding widely existing in the GA/PEG composites (GA-PCMs). The heat storage energy of GA-PCMs is 164.9 J/g, which is 90.2% of the phase change enthalpy of pure PEG. In addition, this composite inherits the natural thermal properties of graphene and thus shows enhanced thermal conductivity compared with pure PEG. This novel study provides an efficient way to fabricate shape-stabilized PCMs with a high content of PEG for thermal energy storage.