Engineering triangular bimetallic metal-organic-frameworks derived hierarchical zinc-nickel-cobalt oxide nanosheet arrays@reduced graphene oxide-Ni foam as a binder-free electrode for ultra-high rate performance supercapacitors and methanol electro-oxidation

Unlocking the potential of a novel hierarchical hybrid (Ni–Co)Se2@NiMoO4@rGO–NF core–shell electrode for high-performance hybrid supercapacitors

“…The isotherm of the NCSe@NMO@rGO–NF nanostructure shows a typical type IV curve with notable hysteresis loops, suggesting the presence of an abundance of mesopores on the surface of the core–shell structure. 43 The PSD curve (inset of Fig. 4i) further demonstrates the presence of ample mesopores with a pore size of 2–30 nm, which are highly beneficial for the diffusion of electrolyte ions during the redox reaction.…”

“…4h) shows the prominent single peak accompanied by other secondary peaks positioned at binding energy values of 284.6, 285.7 and 287.8 eV, representing various functional groups and suggesting the successful deposition of rGO onto the Ni foam substrate. 43,55 The specic surface area coupled with pore size distribution (PSD) of the as-prepared NCSe@N-MO@rGO-NF core-shell structure were analyzed by N 2 adsorption and desorption experiments using Brunauer-Emmett-Teller (BET) analysis, as shown in Fig. 4i.…”

“…5g). Furthermore, the power law and its modified versions were employed to reveal the exact battery-type and capacitive type contributions: 43 i = k 1 v + k 2 v 1/2 i / v 1/2 = k 1 v + k 2 By plotting i / v 1/2 versus v 1/2 , the deductible parameters, k 1 and k 2 , can be obtained from the slope of the linearly fitted line and Y -axis intercept, respectively. The obtained k 1 and k 2 values can be calculated using eqn (5) or (6) to evaluate the diffusive ( k 2 v ) and capacitive ( k 1 v ) contributions, with the results shown in Fig.…”

“…Prior to garnishing rGO, the Ni foam (NF) substrate was carefully cleaned with 2 M HCl via ultrasonication, followed by successive cleaning with de-ionized (DI) water and ethanol and dried at 60 °C for 12 h. Afterwards, the deposition of rGO on Ni foam was carried out according to our previously reported technique. 43…”

“…Prior to garnishing rGO, the Ni foam (NF) substrate was carefully cleaned with 2 M HCl via ultrasonication, followed by successive cleaning with de-ionized (DI) water and ethanol and dried at 60 C for 12 h. Aerwards, the deposition of rGO on Ni foam was carried out according to our previously reported technique. 43 Synthesis of Ni-Co-Se onto rGO-Ni foam (NCSe@rGO-NF) hollow and porous nanotubes Firstly, a 1 : 2 molar ratio of Ni(NO 3 ) 2 $6H 2 O and Co(NO 3 ) 2 -$6H 2 O were dissolved in 50 ml of DI water and the obtained solution was labelled as solution A. In the meantime, solution B was prepared by dissolving 6.35 g of oxalic acid in 50 ml of DI water.…”