Hydrogen storage in a chemical bond stabilized Co₉S₈–graphene layered structure

Abstract

With the high energy ball milling method, a Co9S8-decorated reduced graphene oxide (RGO) composite, which shows excellent hydrogen storage capacity, has been successfully fabricated with a well-organized layered structure. Moreover, the stabilized mechanism of the well-organized layered structure is investigated and attributed to the strong interactions between Co9S8 and defective RGO. The C-S bond interaction is identified and the hydrogen storage process is also studied with different analysis methods. Finally, an optimized Co9S8 to RGO weight ratio of 6:1 shows excellent electrochemical performances in terms of the excellent cycling stability and competitive hydrogen storage capacity of 4.86 wt%.

Chemical Valence‐Dependent Electrocatalytic Activity for Oxygen Evolution Reaction: A Case of Nickel Sulfides Hybridized with N and S Co‐Doped Carbon Nanoparticles

“…The intense satellite peaks suggest that the Ni 2+ state is predominant in the Ni 2p spectra . The high‐resolution S 2p XPS spectra of Ni 9 S 8 ‐NSCs in Figure h reveal the binding peaks at 161.5, 162.5, and 165.0 eV belong to S 2− , S 2 2− , and S n 2− . And the peaks at 163.6 eV (CS) and 168 eV (SO x ) indicate the sulfur doping in carbon substrate .…”

N‐, O‐, and S‐Tridoped Carbon‐Encapsulated Co9S8 Nanomaterials: Efficient Bifunctional Electrocatalysts for Overall Water Splitting

“…In the case of the deconvoluted spectrum of Co2p 3/2 peak, the two peaks located at 778.4 and 781.7 eV were attributed to metallic CoCo and oxidized Co (i.e., CoS groups, in which Co has Co 2+ and Co 3+ oxidation states) . The peak centered at 786.5 eV was due to the shake‐up satellite peak of Co 2+ , indicating the formation of octahedrally coordinated, high‐spin Co 2+ in crystalline Co 9 S 8 . The high‐resolution XPS spectra of Co 9 S 8 @NOSC‐R and the control material NOSC were also obtained, and the results are presented in Figures S15–S18 in the Supporting Information.…”

Co9S8 nanoparticles encapsulated in nitrogen-doped mesoporous carbon networks with improved lithium storage properties

“…The selected area electron diffraction (SAED) pattern indicates that the as obtained Co 9 S 8 @NMCN nanocomposites are polycrystal in nature (Fig. [44][45][46] The C-S peak is attributed to the single bonds between the Co 9 S 8 and the carbon. 19-0364).…”

“…2g), and the diffraction rings can be indexed to the (311), (511), (440), and (731) planes of Co 9 S 8 (JCPDS No. 45,46 The bonding state of N atom in the composite is studied by deconvoluting highresolution N1s spectrum as shown in Fig. Fig.…”