Hollow Carbon Spheres Research Articles

MoS2 nanosheets coupled with double-layered hollow carbon spheres towards superior electrochemical activity

MoS2 nanosheets decorated double-layered hollow carbon spheres (DLHCs@MoS2) were synthesized to form a core-shell structure for enhanced electrochemical activity. Double-layer hollow carbon spheres (DLHCs) was first prepared using a template route while the vertical growth of MoS2 nanosheets was carried out via a hydrothermal synthesis. X-ray absorption near edge structure and X-ray absorption fine structure measurement confirmed that MoS2 was strongly coupled with DLHCs through Mo-O-C hetero-interface. As a dual-functional nanocomposite material, DLHCs@MoS2 revealed ideal performance in terms of hydrogen evolution reaction and supercapacitors. DLHCs as matrix materialsplay an important role to decrease the agglomeration of MoS2 nanosheets, expose more active sites,and improve conductivity. Because of the core-shell structure, DLHCs@MoS2 is more conducive to expose active sites compared with pure MoS2 nanosheets. DLHCs@MoS2 exhibited low Tafel slope and small onset potential. In addition, DLHCs@MoS2 composites used as supercapacitor electrode revealed excellent specific capacitance of 399.4 Fg−1 in acurrent density of 0.5 Ag−1. This result provides an idea for synthesizing low-cost and high-efficiency dual-functional materials.

Tuning the Metal Electronic Structure of Anchored Cobalt Phthalocyanine via Dual‐Regulator for Efficient CO2 Electroreduction and Zn–CO2 Batteries

AbstractHeterogeneous macromolecule catalysts have been known as efficient electrocatalysts for CO2 reduction reaction, however, manipulating the activity of heterogeneous molecules via controllable metal electronic structure is still challenging. Herein, different CO2 activated 3D, robust, nitrogen‐doped hollow carbon spheres are synthesized to anchor cobalt phthalocyanine as molecularly dispersed electrocatalysts, where the electron‐withdrawing coeffect of carbon defects and heteroatom N is responsible for tuning the electronic structure of metal center. The optimal electrocatalyst reveals high CO faradaic efficiency (FECO) of 95.68%, turnover frequency of 13.80 s−1, and current density of 16.49 mA cm−2 at an overpotential of 760 mV. The control experiment and DFT calculations unveil that the significant activity is mainly ascribed to the optimal electron‐withdrawing coeffect of carbon defects and pyrrolic N, which reduce the electron density of Co center to facilitate CO2 activated to form *COOH intermediate on Co(I) active sites during electrocatalysis. The 2p‐charge loss of Co is summarized as an activity descriptor, which steers the current density and production rate toward CO. Furthermore, the design strategy can universally fabricate the hybrid MPc catalyst with transitional metal (Ni, Fe) site while a rechargeable Zn–CO2 battery is devised to deliver a maximal power density of 1.02 mW cm−2.

Ultrathin metallic phase MoS2 nanosheets decorated hollow carbon spheres for sodium and potassium ions storage

Molybdenum disulfide (MoS2) has become a very promising anode material due to its expandable interlayer spacing and high theoretical capacity. Herein, metallic phase MoS2 ultrathin nanosheets in-situ grown on chemically activated hollow carbon spheres (HCS) are synthesized. The 3D conductive structures not only improve the conductivity and shorten the ion diffusion path, but also buffer the volume expansion and avoid the agglomeration of the MoS2 nanosheets. Due to the above advantages, this composite electrode shows considerable storage characteristics. When used as the anode for SIBs, the discharge capacity is 296.2 mA h g−1 at a current density of 0.1 A g−1 after 50 cycles. When used as the anode for PIBs, the discharge capacity reaches 287.8 mA h g−1 after 50 cycles at a current density of 0.1 A g−1. The current synthesis strategy provides an alternative route to develop high performance electrodes for sodium and potassium ions storage.

High capacitive storage behavior of hierarchically porous hollow‑carbon spheres derived from the coupling of template-directing and post-activation methodology

The hierarchically porous hollow‑carbon spheres (HPHCSs) are synthesized by activating the hollow‑carbon spheres (HCSs) derived from the template-directing method using SiO2 spheres and waste tire pyrolysis oil (WTPO) as templates and carbon precursor, respectively. The developed template-directing coupled with post-activation methodology can not only adjust the pore structure of HPHCSs, but also can not destroy the hollow-sphere-like micromorphology. HPHCSs with a relative-intact hollow sphere microarchitecture and abundant micro-mesoporous structure possess the outstanding hydrophilcity and electrical conductivity. As the capacitive energy-storage electrode, HPHCSs electrode presents excellent rate capability, high capacitance retention and good durability in aqueous and organic electrolytes, exhibiting a good compatibility to different kind of electrolyte ions. Besides, the increased ratio of IR drop of HPHCSs electrode is relatively small among the contrast samples possessing different pore structures with the decrease of the test temperature, exhibiting its exceptional low-temperature performance. The favorable combination of template-directing and post-activation is able to realize the controllability of the pore structure of HPHCSs electrode with high capacitive storage behavior. Furthermore, this work also provides a valuable strategy for the preparation of electrode materials with high capacitive energy-storage ability through the high value-added utilization of WTPO.

Double-layered hollow carbon sphere with large interlayer space combined with Co-SnS cat. as efficient sulfur hosts for Li-S batteries

The low sulfur utilization and the serious shuttle effect of polysulfides severely hamper practical application of Li-S batteries. Herein, sulfur cathodes with the multi-functional structures, featured with double-layered hollow carbon sphere with up to 50 nm interlayer space (DLHC-50) in situ grown Co-SnS catalytic layer is designed and synthesized for lithium sulfur batteries. Co-SnS/DLHC-50 can encapsulate 72% sulfur, higher than 63% for Co-SnS/DLHC-20 due to the large interlayer spaces of DLHC-50. Meanwhile, polysulfides are also effectively restricted via physical entrapment from DLHC-50 as well as chemical binding between Co-SnS and polysulfides. Benefiting from the well-constructed host framework, Co-SnS/DLHC-50 @S shows higher specific capacity/capacity retention of 760.4 mA h g−1/72.9% after 500 cycles at 0.5 C, than that of 546.5 mA h g−1/62.2% and 668.9 mA h g−1/62.2%, for DLHC-50 @S, and Co-SnS/DLHC-20 @S, respectively. In addition, the strategy can be also extended to prepare other metal oxides (sulfides)/DLHC-50 for wide applications. Therefore, this work demonstrates a promising route to combat some bottlenecks such as low sulfur utilization, and the shuttle effect of polysulfides for Li-S batteries.

Hollow Carbon Spheres with Rich Nitrogen-Oxygen Dopants and Highly Disordered Adsorption Boundaries for Advanced Lithium and Sodium Storage

Hollow Carbon Spheres with Rich Nitrogen-Oxygen Dopants and Highly Disordered Adsorption Boundaries for Advanced Lithium and Sodium Storage

Ultrahighly nitrogen-doped hollow carbon spheres with hierarchical pores for highly reversible lithium–sulfur batteries

Hollow carbon spheres with 18.94 at% nitrogen doping and hierarchical pores deliver a high specific capacity, excellent capacity performance and long cycling stability in Li–S batteries.

Nitrogen-doped 3D hollow carbon spheres for efficient selective oxidation of C–H bonds under mild conditions

Nitrogen-doped hollow mesoporous carbon spheres present excellent conversion and selectivity in the selective oxidation of ethylbenzene at 50 °C.

Improved hydrogen evolution performance by engineering bimetallic AuPd loaded on amino and nitrogen functionalized mesoporous hollow carbon spheres.

A highly efficient heterogeneous catalyst was synthesized by delicate engineering of NH2-functionalized and N-doped hollow mesoporous carbon spheres (NH2–N-HMCS), which was used for supporting AuPd alloy nanoparticles with ultrafine size and good dispersion (denoted as AuPd/NH2–N-HMCS). Without using any additives, the prepared AuPd/NH2–N-HMCS catalytic formic acid dehydrogenation possesses superior catalytic activity with an initial turnover frequency value of 7747 mol H2 per mol catalyst per h at 298 K. The excellent performance of AuPd/NH2–N-HMCS derives from the unique hollow mesoporous structure, the small particle sizes and high dispersion of AuPd nanoparticles and the modified Pd electronic structure in the AuPd/NH2–N-HMCS composite, as well as the synergistic effect of the modified support.

Metal-free aerobic oxidation of benzyl alcohols over the selective N, P dual-doped hollow carbon sphere as the efficient and sustainable heterogeneous catalyst under mild reaction condition

Nitrogen and phosphorous dual-doped carbon materials are one the promising candidate for the ecofriendly and metal-free heterogeneous catalytic systems owing to the abundance activated sites which is caused by doping the heteroatoms in the carbonaceous materials. The N, P-dual-doped carbon hollow sphere (HPNC-700) precursor prepared via template-assisted strategy by using the SiO 2 as the hard template in the presence of glucose, phosphoric acid and melamine as C, P, and N source, respectively. The resultant catalyst was obtained by pyrolyzing process at 700 °C under N 2 atmosphere by adding the NaOH solution to remove the template. According to various physicochemical analysis including FE-SEM, TEM, XRD, XPS, and Raman spectroscopy, the catalyst exhibited the desired and acceptable properties. So, based on these outcomes, the catalytic efficiency of the HPNC-700 was evaluated in the selective aerobic oxidation of benzyl alcohols. As expected, the HPNC-700 represented the acceptable proficiency in the mentioned reaction with high TOF value, full conversion (>99%) and also the notable recyclability. • P, N-dual doped carbon hollow spheres were designed for selective aerobic oxidation of benzyl alcohols. • SiO 2 spheres were used as the hard templet to synthesis the hollow spheres. • The heterogeneous metal-free HPNC-700 catalyst represents the high efficiency toward oxidation reaction at mild condition. • The more defects in the carbonaceous caused the more efficiency in the catalytic performance. • By doping The P and N in the sructure of carbon, the activated sites were developed in the synthesized catalyst.

Rational Design of Co3s4-Con@N-Doped Carbon Hollow Spheres with Polar S-Co-N Bond as Bifunctional Host Materials for Lithium-Sulfur Batteries

Rational Design of Co3s4-Con@N-Doped Carbon Hollow Spheres with Polar S-Co-N Bond as Bifunctional Host Materials for Lithium-Sulfur Batteries

Effect of different shell structure on lithium storage properties of MoS2 anode

Hollow mesoporous carbon sphere shell (HMCSS) structure of MoS 2 @C and mesosphere petal-like shell (MPLS) structure of TiO 2 @MoS 2 are synthesized by a facile strategy. HMCSS structure can effectively addressed the volume expansion and poor electrical conductivity of MoS 2 , which show that HMCSS structure of MoS 2 @C has higher discharge capacity, better rate capability and cycling performance than MPLS structure of TiO 2 @MoS 2 and pure MoS 2 . • HMCSS structure of MoS 2 @C and MPLS structure of TiO 2 @MoS 2 are synthesized by a facile strategy. • MoS 2 @C exhibit high capacity, remark cycling stability and rate capability compared with TiO 2 @MoS 2 and pure MoS 2 . • The volume expansion and poor electrical conductivity of MoS 2 can be effectively addressed simultaneously. MoS 2 , with a high theoretical specific capacity (670 mAh/g), is a good alternative to traditional graphite as anode for lithium ion batteries (LIBs). Poor conductivity and serious volume expansion during charging and discharging process, however, result in poor cycle performance and rate performance of MoS 2 anode for LIBs. Here, the TiO 2 coated in mesosphere-petal-like shell (MPLS) structure of MoS 2 (TiO 2 @MoS 2 ) and MoS 2 encapsulated in hollow mesoporous carbon spheres shell (HMCSS) structure (MoS 2 @C) are obtained, and effect of different shell structure on lithium storage properties of MoS 2 are investigated. The results show that MoS 2 @C exhibits higher discharge capacity, better rate capability and cycling performance than TiO 2 @MoS 2 and pure MoS 2 . The significantly enhanced charge and discharge performance of MoS 2 @C can be attributed to the improvement of electric conductivity and the inhibition of volume expansion result from the introduction of HMCSS structure. Also, TiO 2 @MoS 2 demonstrates remarkable lithium storage performance in comparison with pure MoS 2 , which is ascribe to MPLS structure of MoS 2 assembled from corresponding 2D nanosheets that facilitates the penetration of electrolyte and provides more sites to accommodate Li + , and which is also attribute to TiO 2 as effective mechanical support and thus alleviate volume expansion and aggregation of MoS 2 during charging and discharging process. It is believed that the different shell structure used in MoS 2 provides a novel approach to enhance the lithium storage performance of metal sulfide.

Graphene oxide wrapped hollow mesoporous carbon spheres as a dynamically bipolar host for lithium–sulfur batteries

An all-carbon based composite composed of hollow mesoporous carbon covered with graphene oxide sheets has been designed as a novel dynamically bipolar cathode host for lithium–sulfur batteries with impressive electrochemical performances.

Green self-activation engineering of metal–organic framework derived hollow nitrogen-doped carbon spheres towards supercapacitors

Hollow nitrogen-doped carbon microspheres are fabricated via a green self-activation strategy, and exhibit attractive electrochemical properties for aqueous supercapacitors.

Atomically Fe doped hollow mesoporous carbon spheres for peroxymonosulfate mediated advanced oxidation processes with a dual activation pathway

The introduction of atomically dispersed Fe atoms can modulate the PMS activation pathway; that is, the radical-mediated process of PMS activation accelerated by graphitic N is attenuated, in turn boosting electron-transfer-mediated nonradical processes.

Minimizing Liquid/Solid Interfacial Energy Boosts Fe−N Doping Inside Hollow Carbon Sphere for Oxygen Reduction in Membrane-Less Direct Formate Fuel Cells

Minimizing Liquid/Solid Interfacial Energy Boosts Fe−N Doping Inside Hollow Carbon Sphere for Oxygen Reduction in Membrane-Less Direct Formate Fuel Cells

Synthesis of Hollow Carbon Spheres by Chemical Activation of Carbon Nanoparticles for Their Use in Electrochemical Capacitor

Synthesis of Hollow Carbon Spheres by Chemical Activation of Carbon Nanoparticles for Their Use in Electrochemical Capacitor

Electronic Structure Regulation of Iron Phthalocyanine Induced by Anchoring on Heteroatom‐Doping Carbon Sphere for Efficient Oxygen Reduction Reaction and Al–Air Battery (Small 2/2022)

Metal–Air Batteries In article number 2105594, Miao Yu, Jie Zhang, and co-workers report the development of iron phthalocyanine (FePc) anchored onto N,S–doped hollow carbon spheres (HNSCs) to form FePc@HNSC. The charge distribution and d–band center of Fe atoms can be efficiently optimized. The material is applied as an efficient oxygen reduction electrocatalyst for aluminum–air batteries.

Herbal residue-derived N, P co-doped porous hollow carbon spheres as high-performance electrocatalysts for oxygen reduction reaction under both alkaline and acidic conditions

Development of carbon-based oxygen reduction reaction (ORR) catalysts with performance superior to noble metals across a wide pH range has been a formidable challenge. Herein, porous hollow carbon spheres co-doped with N, P (NH3-NPCS-900) is directly synthesized from the herbal residues of Lasiosphaera seu Calvatia (LSC). Critically, the N content was significantly enhanced in the presence of ammonia (NH3) and formed a hierarchical porous structure and a large specific surface area (984.7 m2 g−1). With the synergistic effect of these contributions, the NH3-NPCS-900 catalyst exhibit excellent ORR catalytic activity across acidic (E1/2 = 0.615 V) and alkaline solutions (E1/2 = 0.862 V). Zn-air batteries with NH3-NPCS-900 exhibit high peak power density (188 mW cm−2) and better cycle durability (>180 h), showing its potential and promise in applications. This study provides valuable direction and insight into how to develop porous carbon with highly efficient ORR catalytic activity from biomass.

Coordinated regulation of phosphorus/nitrogen doping in fullerene-derived hollow carbon spheres and their synergistic effect for the oxygen reduction reaction.

Fullerene-derived carbons have been demonstrated as effective electrode materials for electrocatalytic reactions. The heteroatoms in the carbon matrix are essential to enhance their electrocatalytic performance but are still challenging for effective doping strategies and understanding their synergistic effect. Herein, we regulate the phosphorus/nitrogen (P/N) doping in the carbon structure based on the control mixing of pyritic acid (PA) with the assembled diamine-C60hollow spheres (N@FHS). After pyrolysis, the carbon spheres are shown to have a homogenous distribution of N and P (NP@CHS). The structural and molecular analysis reveals that the doping of P may facilitate the formation of graphitic N in the carbon framework. When used as electrocatalysts for the oxygen reduction reaction (ORR), NP@CHSs exhibit superior oxygen reduction reaction (ORR) performance in contrast to those of fullerene-derived carbon with single N doping and the commercial Pt/C (20 wt%) catalyst. Density functional theory (DFT) studies indicate that P/N-doping promotes the charge transfer in the carbon structure owing to its strong electronegativity. The enhanced ORR activity should be mainly due to the P- and N-coordinated neighboring C sites with the defective fullerene pentagon ring.