S,N-Containing Co-MOF derived Co₉S₈@S,N-doped carbon materials as efficient oxygen electrocatalysts and supercapacitor electrode materials

Abstract

Co9S8@S,N-doped carbon materials derived from S,N-containing Co-MOFs exhibited superior performance as bifunctional oxygen electrocatalysts and supercapacitor electrode materials.

Reduced Graphene Oxide‐Wrapped Co9–xFexS8/Co,Fe‐N‐C Composite as Bifunctional Electrocatalyst for Oxygen Reduction and Evolution

“…Among them, the transition metal sulfides (TMSs), with relatively lower intrinsic electrical resistivity, have been considered as promising alternative OER catalysts . In particular, cobalt sulfides have received considerable attention due to their low‐cost, conveniently synthesis, and superior activity Moreover, additional element doping is considered as an efficient way to increase the electrocatalytic performance. For instance, Lu and co‐workers have demonstrated Fe‐doped CoS (Co 0.5 Fe 0.5 S@N‐MC) has a superior OER performance than pure CoS with an overpotential of 0.41 V at the current density of 10 mA cm −2 in 1 m KOH, and O‐doped CoS (A‐CoS 4.6 O 0.6 PNCs) is also proved to be an extraordinary catalyst for OER with an E OER ( j = 10 mA cm −2 ) of 0.29 V by Wen and co‐workers Despite such promising progress, compared with OER, their ORR performances are relatively low, severely hindering their applications as efficient bifunctional electrcatalysts for both ORR and OER.…”

POM & MOF‐based Electrocatalysts for Energy‐related Reactions

“…However,a side from ZIF-8 and ZIF-67, there is ap lethora of MOFs whose derived carbonsh ave been tested as electrocatalysts for the energy-related reactions. These MOF templates usually consist of Co [203,[207][208][209][210][211] and Fe [212][213][214][215] cations, and amino-functionalized ligands, for example, benzoimidazole, [207 ] imidazole, [201 ] 2-aminoterephtalic acid (H 2 BDC-NH 2 ), [212,213,216] trimethylamine, [217] 2,2'-bipyridine-5,5'-dicarboxylate (BPDC), [199] 5-amino-1H-tetrazol( 5-AT), [208] etc. Amino-functionalized linkers are preferred in respect to their non-aminated analogousb ecause the presence of Na toms during the pyrolysis process promotes the doping of the emerging carbon resulting in heteroatom-doped carbons, such as N-, S-, B-doped, and dual-doped (e.g.…”

“…In other cases, Co was combined with other elements. For instance, Fe/Co@N-doped graphitic carbonn anocubes derived from polydopamine encapsulatedM OFs were obtained and tested as ORR electrocatalysts in alkaline electrolyte by Xi et al [257] In 2015, Zhang et al [258] focused on Co 3 O 4 @N-doped carbon nanocomposites while, more recently,L iu et al [210] produced and tested towards ORR Co 9 S 8 @S,N-doped carbonbased electrocatalysts from S,N-containing Co-MOFs, achieving E onset = 0.84 Vv s. RHE and E 1/2 = 0.75 Vv s. RHE, which are slightly negative to those for Pt/C (E onset = 0.92 Vv s. RHE and E 1/2 = 0.80 Vv s. RHE), and a n O 2 value of 3.94 (0.2 to 0.6 Vv s. RHE). Authorsa ttributed the ORR electrocatalytic performance to Co 9 S 8 and S, Nd opingi nt he graphitic carbon that provided electrocatalytic active sites, combined with ah igh surfacea rea and appropriate porosity.Z hu et al [259] also prepared a Co 9 S 8 @S,N-doped carbon-based electrocatalystsw ith high ORR activity,b ut using CoCl 2 -a nd thiourea-encapsulated Al-MIL-101-NH 2 as sacrificial MOF.T he material produced at9 00 8C exhibited an E onset = À0.05 Vv s. Ag/AgCl (0.92 Vv s. RHE) and E 1/2 = À0.17 Vv s. Ag/AgCl (0.80 Vv s. RHE), and its calculated electron transfer resulted to be 3.96 (from À0.60 to À0.40 Vv s. Ag/AgCl, 0.37 to 0.57 Vv s. RHE).…”

Controllable Syntheses of MOF‐Derived Materials

“…Moreover, Liu et al. have prepared Co 9 S 8 @S,N‐doped carbon materials through the calcination of S,N‐containing Co‐MOF at 800 °C in the N 2 atmosphere . The above results demonstrate that the heteroatom could still remain in the carbon skeleton, finally affording heteroatom‐doped carbon materials.…”