Efficient electrocatalysts of cobalt phosphide-cobalt sulfide 1D composite nanorods for hydrogen evolution reaction (HER) are synthesized by heat-treatment of cobalt phosphide nanorod under CS 2 flow. The reaction of cobalt phosphide with CS 2 molecule leads to the formation of CoPÀ CoS composite with the maintenance of original 1D nanorod morphology. In comparison with the pristine CoP nanorod, the CoPÀ CoS composite nanorod shows much higher HER electrocatalytic activity with much lower overpotential, highlighting the beneficial effect of composite formation with metal sulfide on electrocatalyst performance of metal phosphide. The composite formation with CoS domain results in the remarkable enhancement of HER kinetics, electrochemical active surface area, and charge transfer kinetics, which is mainly responsible for the enhanced electrocatalytic activity of composite nanorod. The present study underscores that hybridization with metal sulfide can provide an efficient methodology to improve the electrocatalyst functionality of metal phosphide.[a] H.

Efficient water adsorbents with improved hydrostability can be synthesized by the hybridization of metal−organic framework (MOF) compounds with exfoliated layered double hydroxide (LDH) 2D nanosheets. The self-assembly between copper benzene tricarboxylate (Cu-BTC) MOF nanocrystals and exfoliated Mg−Al-LDH nanosheets leads to the nanoscale mixing of the MOF and LDH components, as well as to the prevention of the formation of aggregated secondary MOF particles. In the resulting nanohybrids, spherical Cu-BTC nanocrystals with small particle sizes of ∼5−10 nm are uniformly anchored on the surface of Mg−Al-LDH 2D nanosheets with the dimensions of several hundred nanometers. At the optimal composition, the surface area of the resulting nanohybrid becomes greater than that of pristine Cu-BTC, which is attributable to the suppression of the self-aggregation of MOF nanocrystals and to the formation of the mesoporous stacking structure of the LDH nanosheets. Of prime importance is that both the water adsorption ability and the hydrostability of Cu-BTC become notably improved upon hybridization with LDH nanosheets. The present study clearly demonstrates that exfoliated LDH nanosheets can be used as an effective hybridization matrix for exploring novel efficient MOF-based hybrid water adsorbents.

No abstract

Hybridization between low-dimensional nanostructures has received considerable research interest, owing to its usefulness in the exploration of energyefficient functional materials. In the present study, an effective method to synthesize high-performance electrocatalysts was established by employing monolayered twodimensional RuO 2 nanosheets and Co 2+ ions as conductive additives and linker species, respectively. Intimately coupled hybrid electrocatalysts of Co−MoS 2 −RuO 2 were synthesized through the self-assembly of isocharged MoS 2 nanoflowers and RuO 2 nanosheets using oppositely charged Co 2+ linkers. Efficient interfacial charge transfer from RuO 2 nanosheets to MoS 2 nanostructures can be achieved via electrostatically driven strong electronic coupling between MoS 2 /RuO 2 nanostructures promoted by Co 2+ linkers. The co-incorporation of RuO 2 nanosheets and Co 2+ ion linkers was found to be considerably effective for optimization of the electrocatalyst performance and electrochemical stability of MoS 2 nanoflowers for the hydrogen evolution reaction in acidic and alkaline electrolytes. The beneficial roles of RuO 2 nanosheets and Co 2+ ions in the optimization of the electrocatalyst performance were attributable to the improvement of electrocatalysis kinetics, the expansion of the electrochemical active surface area, and the promotion of charge transport upon hybridization.

A novel methodology to explore efficient CO2 adsorbent is developed by the stabilization of layered double oxide (LDO) in the hybrid matrix of reduced graphene oxide (rG-O) and layered titanate nanosheets. The electrostatically derived self-assembly between cationic Mg–Al–layered double hydroxide (LDH) nanosheet and anionic graphene oxide (G-O)/layered titanate nanosheets followed by heat treatment at high temperature leads to the cohybridization of LDO (MgO/MgAl2O4) nanocrystals with exfoliated rG-O and layered titanate nanosheets. The incorporation of LDO into the hybrid matrix of rG-O and layered titanate nanosheets is highly effective in increasing its surface area through the formation of mesoporous stacking structure. Of prime importance is that even at very low concentration of titanate (0.3 wt %), an addition of layered titanate nanosheet induces a remarkable surface area expansion of LDO–rG-O nanocomposite from 178 to 330 m2 g–1. This result is attributable to the depression of the self-aggregation of rG-O nanosheets due to the incorporation of layered titanate nanosheet. The resulting LDO–rG-O–layered titanate nanocomposite shows promising CO2 adsorption capability of 1.71 mmol g–1 at 273 K, which is much greater than those of LDO (0.79 mmol g–1) and LDO–rG-O nanocomposites (1.19 mmol g–1), highlighting the remarkable advantage of titanate addition to improve the CO2 adsorptivity of LDO. The present study clearly proves that the restacked assembly of rG-O nanosheet and layered metal oxide one has potential applications as an efficient hybrid matrix for exploring high performance gas adsorbent.