Large-scale chemical vapor deposition synthesis of graphene nanoribbions/carbon nanotubes composite for enhanced membrane capacitive deionization

The composite comprised of graphene and carbon nanotubes (CNTs) exhibited significantly enhanced electro-chemical performance due both to the improved dispersion and inhibition of restacking of graphene and CNTs. In this work, graphene nanoribbons (GNRs)/CNTs composite (GNRs/CNTs) was synthesized on gram-scale by chemical vapor deposition. Under optimal growth conditions, the yield of GNRs/CNTs as high as 26 g per gram catalyst could be achieved in 30 min growth time. The morphology and quality of the as-synthesized composite was verified by using SEM, TEM and Raman spectroscopy. The electrochemical properties of GNRs/CNTs was evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge techniques. GNRs/CNTs exhibited specific capacitance of 242.3 F/g at 0.5 A g(-1), which was over 4 times of that of CNTs. The GNRs/ CNTs based electrodes exhibited excellent cycling stability at 1 A g(-1) for over 4000 cycles, which can be attributed to the excellent electrical conductivity and the unique structure. When employed as electrode for membrane capacitive desalination, the desalination capacity of 16.46 mg g(-1) has been achieved under 1.2 V with 500 mg L-1 NaCl solution as feeding water

Facile Synthesis of Yolk–Shell Mn3O4 Microspheres as a High-Performance Peroxymonosulfate Activator for Bisphenol A Degradation

Manganese-based materials have been regarded as a kind of widely used heterogeneous catalysts for peroxymonosulfate (PMS) activation in water remediation. In this work, yolk–shell Mn3O4 (YS-Mn3O4) microspheres with a porous structure were synthesized by a simple hydrothermal method with manganese glycerate (Mn-GL) as a self-sacrificing template. YS-Mn3O4 exhibits high Brunauer–Emmett–Teller surface area (81.0 m2/g) and pore volume (0.18 cm3/g), which are essentially favorable for the development of its catalytic activity. When YS-Mn3O4 is employed as a PMS activator, it can exhibit good performance in the degradation of bisphenol A (BPA). Some influential parameters, such as catalyst dosage, oxone concentration, reaction temperature, BPA concentration, and pH value, and some inorganic ions have been analyzed in detail. Electron paramagnetic resonance examination and radical quenching results demonstrate that •OH and •SO4– should be responsible for the rapid decomposition of BPA in the YS-Mn3O4/PMS system. This work will be significant for tailoring the morphology of materials and arousing more attention to enhance the stability and reusability of catalysts

Ni2P nanocrystals embedded Ni-MOF nanosheets supported on nickel foam as bifunctional electrocatalyst for urea electrolysis

It's highly desired but challenging to synthesize self-supporting nanohybrid made of conductive nanoparticles with metal organic framework (MOF) materials for the application in the electrochemical field. In this work, we report the preparation of Ni2P embedded Ni-MOF nanosheets supported on nickel foam through partial phosphidation (Ni2P@Ni-MOF/NF). The self-supporting Ni2P@Ni-MOF/NF was directly tested as electrode for urea electrolysis. When served as anode for urea oxidation reaction (UOR), it only demands 1.41 V (vs RHE) to deliver a current of 100 mA cm(-2). And the overpotential of Ni2P@Ni-MOF/NF to reach 10 mA cm(-2) for hydrogen evolution reaction HER was only 66 mV, remarkably lower than Ni2P/NF (133 mV). The exceptional electrochemical performance was attributed to the unique structure of Ni2P@Ni-MOF and the well exposed surface of Ni2P. Furthermore, the Ni2P@Ni-MOF/NF demonstrated outstanding longevity for both HER and UOR. The electrolyzer constructed with Ni2P@Ni-MOF/NF as bifunctional electrode can attain a current density of 100 mA cm(-2) at a cell voltage as low as 1.65 V. Our work provides new insights for prepare MOF based nanohydrid for electrochemical application