Nitrogen-doped multiwalled carbon nanotubes decorated with copper(I) oxide nanoparticles with enhanced capacitive properties

Electrochemical Nitrogen Reduction Kinetics on a Copper Sulfide Catalyst for NH3Synthesis at Low Temperature and Atmospheric Pressure

“…The chemical state of the CuS surfaces determined by XPS reveals that the majority of Cu on the surface has oxidation numbers of 2+ and 1+ (Figure b). Cu­(II) was primarily observed at electron binding energies of 932.4 and 952.3 eV for Cu 2p 3/2 and Cu 2p 1/2 , respectively, while Cu­(I) peaks were located at 933.6 and 953.5 eV. − In the XPS spectra, Cu­(II) and Cu­(I) accounted for 51% and 49%, respectively, implying the existence of reduced Cu­(I) at the top-most surfaces of CuS. We speculate that the surface of Fe–CuS/C is a mixture of amorphous Cu 2 S and CuS, while the bulk crystal exhibits the hexagonal CuS structure based on the XRD and XPS analysis.…”

Carbon Nanotubes@Nickel Cobalt Sulfide Nanosheets for High‐Performance Supercapacitors

“…To investigate the structural features of the CNTs@NiCo 2 S 4 , the Raman spectra of the samples were also collected (Figure c). Two strong peaks at 1351 cm −1 (D band) and 1585 cm −1 (G band) can be found on all the materials, which are characteristics of the defective sites (D band) and the sp 2 ‐hybridized carbon atoms in the graphitic framework of CNTs . The ratio of I D and I G (I D /I G ) indicates the degree of defects in the CNTs.…”

Progress in supercapacitors: roles of two dimensional nanotubular materials

“…As reported by Sharma et al, 393 hollow nanostructures of copper oxides with various morphologies have counteracted electrochemical stabilization in their solid counterparts where higher specic capacitance values through cyclic voltammetry and charge-discharge studies have been reported compared to copper oxide-based composites with CNTs, graphene and rGO. The specic capacitance as reported was estimated to be 144 F g À1 at a current density of 1.0 A g À1 as compared to conventional Cu 2 O/rGO, 394 microstructures, 395 and nanoparticle-MWCNTs 396 with capacitance values of 31 F g À1 , 173 F g À1 , and 132 F g À1 at current density values of 0.1 A g À1 , 0.1 A g À1 , and 2.5 A g À1 respectively. The rst metal oxides (RuO 2 ), which brought limelight to pseudo-capacitors with very high specic capacitance values was never used as a framework for energy storage devices, 397 due to high toxicity and cost.…”