Sea-Island-Like Morphology of CuNi Bimetallic Nanoparticles Uniformly Anchored on Single Layer Graphene Oxide as a Highly Efficient and Noble-Metal-Free Catalyst for Cyanation of Aryl Halides.

Aryl nitriles are versatile compounds that can be synthesized via transition-metal-mediated cyanation of aryl halides. Most of the supported-heterogeneous catalysts are noble-metals based and there are very limited numbers of efficient non-noble metal based catalysts demonstrated for the cyanation of aryl halides. Herein, bimetallic CuNi-oxide nanoparticles supported graphene oxide nanocatalyst (CuNi/GO-I and CuNi/GO-II) has been demonstrated as highly efficient system for the cyanation of aryl halides with K4[Fe(CN)6] as a cyanating agent. Metal-support interaction, defect ratio and synergistic effect with the bimetallic nanocatalyst were investigated. To our delight, the CuNi/GO-I system activity transformed a wide range of substrates such as aryl iodides, aryl bromides, aryl chlorides and heteroaryl compounds (Yields: 95-71%, TON/TOF: 50-38/2 h-1). Moreover, enhanced catalytic performance of CuNi/GO-I and CuNi/GO-II in reduction of 4-nitropehnol with NaBH4 was also confirmed (kapp = 18.2 × 10-3 s-1 with 0.1 mg of CuNi/GO-I). Possible mechanism has been proposed for the CuNi/GO-I catalyzed cyanation and reduction reactions. Reusability, heterogeneity and stability of the CuNi/GO-I are also found to be good.

Metal-organic-framework-derived hierarchical Co/CoP-decorated nanoporous carbon polyhedra for robust high-energy storage hybrid supercapacitors.

Electrode materials exhibiting nanostructural design, high surface area, tunable pore size, and efficient ion diffusion/transportation are essential for achieving improved electrochemical performance. In this study, we successfully prepared cobalt phosphide and cobalt nanoparticles embedded into nitrogen-doped nanoporous carbon (CoP-CoNC/CC) using a simple precipitation method followed by pyrolysis-phosphatization. Subsequently, we employed CoP-CoNC/CC as the electrode for supercapacitor applications. Notably, the resultant CoP-CoNC/CC displayed a high surface area with tunable porosity. Based on the benefits of the CoP in CoNC/CC, improved electrochemical performance was achieved with a specific capacitance of 975 F g-1 at 1 mA cm-2 in a 2 M KOH electrolyte. The assembled hybrid supercapacitor using CoP-CoNC/CC (positive electrode) and activated carbon (AC) (negative electrode) exhibited a specific capacitance of 144 F g-1, a specific energy of 39.2 W h kg-1 at 1960 W kg-1 specific power, with better cyclic stability. The higher performance can be attributed to the synergetic effect between CoP, Co metal, and the nitrogen-doped nanoporous carbon in three-dimensional carbon cloth (CC). These excellent properties make CoP-CoNC/CC a promising electrode for developing future energy-storage devices.