Bimetal‐organic Framework‐derived Co₉S₈/ZnS@NC Heterostructures for Superior Lithium‐ion Storage

Abstract

Heterostructure engineering of electrode materials, which is expected to accelerate the ion/electron transport rates driven by a built-in internal electric field at the heterointerface, offers unprecedented promise in improving their cycling stability and rate performance. Herein, carbon nanotubes with Co 9 S 8 /ZnS heterostructures embedded in a N-doped carbon framework (Co 9 S 8 /ZnS@NC) have been rationally designed via an in-situ vapor chemical transformation strategy with the aid of thiophene, which not only acted as carbon source for the growth of carbon nanotubes but also as sulfur source for the sulfurization of metal Zn and Co. Density functional theory (DFT) calculation shows an about 3.24 eV electrostatic potential difference between ZnS and Co 9 S 8 , which results in a strong electrostatic field across the interface that makes electrons transfer from Co 9 S 8 to the ZnS side. As expected, a stable cycling performance with reversible capacity of 411.2 mAh g À 1 at 1000 mA g À 1 after 300 cycles, excellent rate capability (324 mAh g À 1 at 2000 A g À 1 ) and a high percentage of pseudocapacitance contribution (87.5% at 2.2 mv/s) for lithium-ion batteries (LIBs) are achieved. This work provides a possible strategy for designing multicomponent heterostructural materials for application in energy storage and conversion fields.[a] Prof.

Bimetallic-MOF-Derived ZnxCo3–xO4/Carbon Nanofiber Composited Sorbents for High-Temperature Coal Gas Desulfurization

“…The high-resolution TEM image (Figure 2l) and magnifications corresponding to boxes 1 and 2 indicate the presence of Co 9 S 8 and ZnS. 44 Moreover, the lattice fringes with a spacing distance of 0.298 and 0.198 nm are found, which should correspond to the planes of (222) in Co 9 S 8 and (220) in ZnS, consistent with the XRD observation (Figure 2m,n).…”

“…79-2204). 44 .17 to 1.33 compared with that of pristine CNFs (Figure S9), which can be ascribed to the increase in the structural defects of CNFs introduced through the hydrothermal reaction of Zn/Co−ZIF, and the decrease in the G band intensity resulting from the reduction of graphitic layers. 41 However, after desulfurization, the I D /I G value of Co 9 S 8 /ZnS/CNFs decreases to 1.04, which might be the result of the influence of the desulfurization reaction.…”

Sulfur Vacancy-Rich Carbonaceous Co9S8-ZnS Nanotubes for the Oxygen Evolution Reaction

“…18 Engineering a Co 9 S 8 -containing heterostructure normally improves the electrocatalytic performance over its single-component counterpart through interface coupling and vacancy construction. 19,20 The interface of the heterostructure shows the favorable chemisorption of the oxygen-containing intermediates 21−23 and the exposed interface vacancies can effectively regulate the electronic structure to expose a large number of unsaturated sites, improve the intrinsic activity and conductivity of active sites, optimize the adsorption/desorption energetics of intermediates, and thus significantly promote the reaction kinetics and speed up the reaction rate. 24−27 Despite much progress being achieved, the inferior micro/nanostructure of the present Co 9 S 8 -containing composite catalysts increases the difficulty of charge/mass transport, which hampers their efficient functionality.…”

CoS2 Nanoparticles Anchored on MoS2 Nanorods As a Superior Bifunctional Electrocatalyst Boosting Li2O2 Heteroepitaxial Growth for Rechargeable Li‐O2 Batteries

“…Heterostructures are typically made up of different components with different band gaps, and heterointerface engineering has been deemed to be a crucial way to create defect‐rich interfaces for bimetal sulfide hybrids. [ 18 ] Compared with single metal sulfides, binary metal sulfides show much higher electrical conductivity and advanced redox reactions, which are due to their abundant and more exposed active sites with favorable chemical reactivity. [ 19 ] The heterointerfaces between different components of bimetal sulfides can generate a strong built‐in electric field and significantly increase the electrochemically active reaction sites to facilitate interface charge transport of ions and electrons, thus improving the reaction kinetics.…”

“…[ 19 ] The heterointerfaces between different components of bimetal sulfides can generate a strong built‐in electric field and significantly increase the electrochemically active reaction sites to facilitate interface charge transport of ions and electrons, thus improving the reaction kinetics. [ 18a,20 ]…”