Sulfur Dual-doped Carbon Research Articles

Mesoporous Nickel Sulfide Microsphere Encapsulated in Nitrogen, Sulfur Dual-Doped Carbon with Large Subsurface Region for Enhanced Sodium Storage.

Nickel sulfides are promising anode candidates in sodium ion batteries (SIBs) due to high capacity and abundant reserves. However, their applications are restricted by poor cycling stability and slow reaction kinetics. Thus, mesoporous nickel sulfide microsphere encapsulated in nitrogen, sulfur dual-doped carbon (MNS@NSC) is prepared. The packaged structure and carbon matrix restrain the volume variation together, the N, S dual-doping improves the electronic conductivity and offers extra active sites for sodium storage. Ex-situ X-ray diffraction appeals copper collector adsorbs polysulfide to inhibit the polysulfide accumulation and enhance conductivity. Moreover, the large subsurface attributed to C-S-S-C bonding further boosts pseudocapacitive capacity, conducive to charge transfer. As a result, MNS@NSC delivers a high reversible capacity of 640.2 mAh g-1 after 100 cycles at 0.1 A g-1, an excellent rate capability (569.8 mAh g-1 at 5 A g-1), and a remained capacity of 513.8 mAh g-1 after undergoing 10000 circulations at 10 A g-1. The MNS@NSC|| Na3V2(PO4)3 full cell shows a cycling performance of specific capacity of 230.8 mAh g-1 after 100 cycles at 1 A g-1. This work puts forward a valid strategy of combing structural design and heteroatom doping to synthesize high-performance nickel sulfide materials in SIBs.

Volatile guest molecule mediated strategy to convert covalent organic framework into nitrogen, sulfur-doped carbon as metal-free oxygen reduction electrocatalysts

Covalent organic framework (COF) derived metal-free carbon materials have emerged as promising electrocatalysts for the oxygen reduction reaction (ORR). Herein, a volatile guest molecule mediated-pyrolysis strategy was explored on a designed thiophene-rich and imine-linked COF. Through the modulation of guest mediators (iodine and sulfur), the properties of the as-obtained carbon materials can be well regulated. The optimized nitrogen and sulfur dual-doped carbon electrocatalyst demonstrates remarkable ORR activity with a half-wave potential of 0.87 V and impressive durability, with only an 8% current loss over 21 h. The corresponding assembled zinc-air battery has a comparable power density (60 mW cm−2) to that of the commercial Pt/C. It is proposed that the coexistence of the guest mediators iodine and sulfur in the channels of COFs could prevent the loss of N species. The enhanced N content and N/S ratio are assumed to be responsible for the ORR performance. This study puts forward a novel strategy to prepare COF-derived carbon materials mediated by volatile guest molecules, which may provide new insights into the development of metal-free ORR catalysts.

High-Performance Sodium-Ion Batteries Enabled by 3D Nanoflowers Comprised of Ternary Sn-Based Dichalcogenides Embedded in Nitrogen and Sulfur Dual-Doped Carbon.

To make sodium-ion batteries a realistic option for everyday energy storage, a practicable method is to enhance the kinetics of Na+ reactions through the development of structurally stable electrode materials. This study utilizes ternary Sn-based dichalcogenide (SnS1.5 Se0.5 ) in the design of electrode material to tackle several issues that adversely hinder the performance and longevity of sodium-ion batteries. First, the incorporation of Se into the SnS structure enhances its electrical conductivity and stability. Second, the ternary composition restricts the formation of intermediates during the desodiation/sodiation process, resulting in better electrode reaction reversibility. Finally, SnS1.5 Se0.5 lowers the diffusion barrier of Na, thereby facilitating rapid and efficient ion transport within the electrode material. Moreover, nitrogen and sulfur dual-doped carbon (NS-C) is used to enhance surface chemistry and ionic/electrical conductivity of SnS1.5 Se0.5 , leading to a pseudocapacitive storage effect that presents a promising potential for high-performance energy storage devices. The study has successfully developed a SnS1.5 Se0.5 /NS-C anode, exhibiting remarkable rate capability and cycle stability, retaining a capacity of 647 mAh g-1 even after 10000 cycles at 5 A g-1 in half-cell tests. In full-cell tests, Na3 V2 (PO4 )3 //SnS1.5 Se0.5 /NS-C delivers a high energy density of 176.6 Wh kg-1 . In addition, the Na+ storage mechanism of SnS1.5 Se0.5 /NS-C is explored through ex situ tests and DFT calculations. The findings suggest that the ternary Sn-based dichalcogenides can considerably enhance the performance of the anode, enabling efficient large-scale storage of sodium. These findings hold great promise for the advancement of high-performance energy storage devices for practical applications.

The performance of heteroatom-doped carbon nanotubes synthesized via a hydrothermal method on the oxygen reduction reaction and specific capacitance

Due to the increasing demand for electrochemical energy storage, various novel electrode and catalysis materials for supercapacitors and rechargeable batteries have developed over the last decade. The structure and characteristics of these catalyst materials have a major effect on the device's performance. In order to lower the costs associated with electrochemical systems, electrochemical systems, metal-free catalysis materials can be employed. In this study, metal-free catalysts composed of nitrogen (N) and sulfur (S) dual-doped multi-walled carbon nanotubes were synthesized using a straightforward and cost-effective single-step hydrothermal method. Carbon nanotubes served as the carbon source, while l-cysteine amino acid and thiourea acted as doping elements. As a result of the physicochemical characterization, many defects and a porous structure were noted, along with the successful insertion of nitrogen and sulfur into the carbon nanotube was confirmed. According to the cyclic voltammetry tests for the dual-doped samples in alkaline conditions, the D-CNT2 catalyst exhibited onset potentials of -0.30 V higher than the -0.37 V observed for the D-CNT3 catalyst. This indicates enhanced oxygen–reduction reaction due to the synergistic effects of the heteroatoms in the structure and the presence of chemically active sites. Moreover, the outstanding specific capacitance of the D-CNT2 catalyst (214.12 F g-1 at scanning rates of 1 mV s-1) reflects the effective porosity of the proposed catalyst. These findings highlight the potential of N/S dual–doped carbon nanotubes for electrocatalytic applications, contributing to efficient energy conversion.

Thiourea-assisted nitrogen and sulfur dual-doped carbon nanofibers for enhanced supercapacitive energy storage

Thiourea-assisted nitrogen and sulfur dual-doped carbon nanofibers for enhanced supercapacitive energy storage

Two-Dimensional Co/Co9S8 Nanoparticles Decorated N, S Dual-Doped Carbon Composite as an Efficient Electrocatalyst for Zinc-Air Battery

Substituting costly Pt-based oxygen reduction reaction (ORR) catalysts with highly active and stable non-precious metal catalysts is a great challenge in zinc-air batteries. Herein, we fabricated Co/Co9S8 nanoparticles decorated nitrogen, sulfur dual-doped carbon leaves (Co/Co9S8-NCL) with outstanding ORR performance by pyrolysis of dithiooxamide (DTO) molecule modified two-dimensional (2D) leaf-shaped zeolitic imidazolate framework (ZIF-L). The functionality of DTO simultaneously optimizes 2D nanostructure and component (S doping) by the confinement effect due to the coordination interaction between S atoms of DTO and Co2+ in ZIF-L. Benefiting from the synergistic effect between Co-Nx sites and Co/Co9S8 species coupled with unique two-dimensional N, S-codoped carbon leaves, the resulting Co/Co9S8-NCL-30 exhibits a remarkable ORR activity with a half-wave potential of 0.852 V comparable to Pt/C (0.843 V) and outstanding long-term stability. Impressively, the Zn-air battery with Co/Co9S8-NCL-30 achieves high power density of 112 mW cm−2 and specific capacity of 799 mAh g−1Zn. This work will present a new pathway to prepare highly active and durable 2D transition metal-based carbon nanomaterials in zinc-air batteries.

Boosting the lithium storage performance by synergistically coupling ultrafine heazlewoodite nanoparticle with N, S co-doped carbon

Transition metal sulfides, as an important class of inorganics, have been shown to be potential high-performance electrode candidates for lithium-ion batteries (LIBs) in account of their high activity towards lithium storage, rich types and diverse structures. Despite these advantages, structure degradation related with volume variations upon electrochemical cycling restricts their further development. In this present study, a unique hybrid structure with ultrafine heazlewoodite nanoparticles (less than 10 nm) in-situ confined in nitrogen and sulfur dual-doped carbon (Ni3S2@NSC) was constructed though a facile pyrolysis process, using a novel Ni-based metal chelates as the precursor. Specifically, enhanced structure stability, shortened Li+ migration distance and improved reaction dynamics can be obtained simultaneously in the designed structure, thereby allowing to realize high lithium storage performance. Consequently, a remarkable reversible capacity of 955.9 mAh g−1 (0.1 A g−1 after 100 cycles) and a superior long-term cycling stability up to 1200 cycles (863.7 mAh g−1 at 1.0 A g−1) are obtained. Importantly, the fundamental understanding on the improved lithium storage of Ni3S2@NSC based on the synergistic coupling reveals that the combination between Ni3S2 and NSC at the hetero-interface through the doped sulfur atoms contributes to the integrity of electrode and improved kinetics.

Realizing efficient sodium storage property with NASICON-type Na2VTi(PO4)3 modified by nitrogen and sulfur dual-doped carbon layer for sodium ion batteries

As a promising cathode for sodium ion batteries, polyanion-type phosphate compounds are considered as a potential candidate of the next-generation sodium storage materials for the three-dimensional (3D) structure and open pathways. However, several intrinsic faults, such as low electrical conductivity seriously prevent their practical application in broader fields. Herein, the nitrogen and sulfur co-doped carbon layer coated Na2VTi(PO4)3 nanocomposites have been synthesized by a facile sol-gel method. The crystal structure, surface morphology and charge-discharge performance were investigated to confirm the successful preparation of target particles and the substitution of nitrogen and sulfur elements. Among these prepared materials, the optimal sample can display a satisfactory discharge capacity of 164.85 mAh g−1 and high capacity retention of 96.5% after thirty cycles. Meanwhile, the superior rate properties and rapid reaction kinetics are achieved as a result of high electrical conductivity and fast ion diffusion coefficient, resulting in an enhanced electrochemical performance. The route in this paper may provide guidance to a large-scale commercial production of energy storage devices.

Achieving Ultrahigh Volumetric Energy Storage by Compressing Nitrogen and Sulfur Dual-Doped Carbon Nanocages via Capillarity.

High volumetric performance is a challenging issue for carbon-based electrical double-layer capacitors (EDLCs). Herein, collapsed N,S dual-doped carbon nanocages (cNS-CNC) are constructed by simple capillary compression, which eliminates the surplus meso- and macropores, leading to a much increased density only at the slight expense of specific surface area. The N,S dual-doping induces strong polarity of the carbon surface, and thus much improves the wettability and charge transfer. The synergism of the high density, large ion-accessible surface area, and fast charge transfer leads to state-of-the-art volumetric performance under the premise of high rate capability. At a current density of 50 A g-1 , the optimized cNS-CNC delivers a high volumetric capacitance of 243 and 199 F cm-3 in KOH and EMIMBF4 electrolyte, with high energy density of 7.9 and 93.4Wh L-1 , respectively. A top-level stack volumetric energy density of 75.3Wh L-1 (at power density of 0.7kW L-1 ) and a maximal stack volumetric power density of 112kW L-1 (at energy density of 18.8Wh L-1 ) are achieved in EMIMBF4 , comparable to the lead-acid battery in energy density but better in power density with 2-3 orders. This study demonstrates an efficient strategy to design carbon-based materials for high-volumetric-performance EDLCs with wide practical applications.

Coupling highly dispersed Sb2S3 nanodots with nitrogen/sulfur dual-doped porous carbon nanosheets for efficient immobilization and catalysis of polysulfides conversion

• Ultrafine Sb 2 S 3 nanodots serve as adsorbents and catalysts for lithium polysulfides. • Highly N/S Dual-doped carbon matrix guarantees the high conductivity. • Tiny Sb 2 S 3 nanodots guide the Li 2 S to uniformly deposit on carbon matrixes. • The S-NSCNLs@Sb 2 S 3 cathodes exhibit enhanced cyclic stability. Low cost and high energy density lithium-sulfur batteries show great promise for powering next-generation energy storage system. However, the practical application is greatly hindered by the poor cathode conductivity and the shuttle effect of soluble lithium polysulfides. Herein, a leaf-like nanosheets composing of highly dispersed Sb 2 S 3 nanodots embedded in highly nitrogen (18.9%) and sulfur dual-doped porous carbon skeleton (NSCNLs@Sb 2 S 3 ) is designed for efficient immobilization and catalysis of polysulfides conversion by a facile approach. The conductive carbon matrix effectively enhances the conductivity. Nitrogen/sulfur doping species and Sb 2 S 3 nanodots provide abundant stable active sites to anchor lithium polysulfides. Moreover, a series of fundamental experiments reveal that the Sb 2 S 3 nanodots can boost the redox reaction kinetics and guide the polysulfide to uniformly deposit on carbon matrixes, leading to a stable electrode structure. Benefiting from the unique design of the structure and rational componential selection, the S-NSCNLs@Sb 2 S 3 electrodes deliver a stable capacity after 800 cycles with a capacity fade rate of 0.029% per cycle at 1.0 C and an excellent rate capacity of 567 mAh g −1 at 4.0 C. This present work with facile synthetic process may provide a new sight for the designing and practical application of carbon-based sulfur storage materials.

Encapsulated Ni3S2 nanoparticles with N, S dual-doped carbon nanotubes: A robust structure for lithium storage

Abstract Nickel sulfides are regarded as advanced candidates for anode of lithium ion battery (LIBs). However, the huge volume change and the poor conductivity hinder their practical application in energy storage. In this paper, Ni3S2 nanoparticles in-situ encapsulated into nitrogen and sulfur dual-doped carbon nanotubes (Ni3S2/NSCNTs) hybrid is synthesized by a facile and scalable approach. When used as an anode for LIBs, Ni3S2/NSCNTs hybrid exhibits a long cycling life (84% capacity retention after 300 cycles at 0.5 A g−1) and an outstanding rate capability (374.1 mAh g−1 at 3 A g−1). These results are ascribed to the special and robust architecture, in which the NSCNTs can enhance the conductivity and maintain structural integrity of hybrid during cycles. This study demonstrates a simple and scalable synthesis strategy toward preparing anode materials for electrochemical energy storage.

Nitrogen and sulfur dual-doped porous carbon derived from coffee waste and cysteine for electrochemical energy storage

N/S dual-doped carbon materials were synthesized from coffee waste and cysteine for use as porous carbon electrode materials for electric double layer capacitors. The capacitance of the carbon materials was calculated from the experimental results of cyclic voltammetry and galvanostatic charge-discharge tests. The N/S-doped carbon materials obtained from heat-treatment with cysteine exhibited a higher discharge capacitance, 71.3 F/g, than that of the carbon without the cysteine treatment, 43.8 F/g, at 1 A/g. This is because the N/S dual-doped carbons possess a higher wettability than that of the other carbon material, even though the N/S doping with cysteine destroys the porous carbon structure, which reduces the BET surface area of the carbon samples. Elemental analysis was performed to determine the portions of nitrogen and sulfur elements doped into the carbon. From the XPS results, various states of nitrogen and sulfur elements were identified, and SEM/TEM images were obtained to observe their morphologies and porous structures.

Functionalized carbon quantum dots as fluorescent nanoprobe for determination of tetracyclines and cell imaging.

Nitrogen and sulfur co-doped carbon dots (N, S-CQDs) with high fluorescent, water-soluble, low-toxicity properties were synthesized by microwave-assisted hydrothermal approach. The prepared N, S-CDs exhibited high selectivity in detection of tetracyclines (TCs) and displayed afast-responsive fluorescence quenching signal in the mixture, which aremainly attributed to the inner filter effect (IFE). The synthesized N, S-CQDs are successfully used as a fluorescent nanoprobe for the determination of CTC in milk samples (with excitation/emission maxima at 373/424nm). The limit of detection (LOD) is 71ngmL-1, and the recoveries of spiked samples range from 96 to 104% with a relative standard deviations (RSDs) less than 2.7% (n= 3). Additionally, the cytotoxicity and optical imaging performance of N, S-CQDs were preliminarily evaluated. The results indicate the low-toxicity and good biocompatibility of the N, S-CQDs and their promising future as fluorescent-imaging agents in pharmaceutical analysis. Graphical Abstract Synthesis flowchart and application of nitrogen and sulfur dual-doped carbon quantum dots.

Nitrogen and sulfur dual-doped carbon nanotube derived from a thiazolothiazole based conjugated microporous polymer as efficient metal-free electrocatalysts for oxygen reduction reaction

The present report demonstrates a simple approach for the synthesis of efficient metal-free electrocatalysts of nitrogen- and sulfur-codoped carbon materials (N–S-DPCs) via carbonization of thiazolothiazole based conjugated microporous polymer precursors (XWB-CMP). The precursors are composed of densely populated thiazolothiazole units that uniformly decorate over the micropore surface and can be readily converted into novel N–S-DPCs with a uniform nitorgen/sulfur distribution by template-free pyrolysis. The electrochemical characterization demonstrates that N–S-DPCs obtained at pyrolysis temperature of 1000 °C exhibits a high electrocatalytic activity toward oxygen reduction reaction (ORR), superior durability, good methanol tolerance as compared to the commercial Pt/C catalyst. The present work sheds insights into the effects of heteroatom doping on ORR electrocatalysts.

N,S dual-doped carbon nanosheet networks with hierarchical porosity derived from biomass of Allium cepa as efficient catalysts for oxygen reduction and Zn–air batteries

Efficient metal-free electrocatalysts for oxygen reduction reactions (ORR) have been actively pursued in recent years to promote the application of fuel cells and metal–air batteries. In this work, hierarchically porous nitrogen and sulfur dual-doped carbon nanosheet networks (N,S-HPC) were facilely synthesized by pyrolysis of Allium cepa chips impregnated with thiourea and KOH. The as-prepared N,S-HPC featured high content of N and S dopants (5.32 at.% for N and 2.23 at.% for S, respectively), abundant catalytically active sites, unique hierarchically porous architecture, large surface area (1859 m2 g−1) and exhibited remarkable electrocatalytic activity toward ORR with positive onset/half-wave potential and large limiting diffusion current. In addition, N,S-HPC showed much better long-time stability and resistance to methanol crossover than Pt/C did. When used as the cathodic catalysts of Zn–air battery, N,S-HPC outperformed Pt/C in terms of the open-circuit potential, discharge current density, peak power density, specific capacity and rate performance, showing promise as an alternative to Pt/C for application in fuel cells and metal–air batteries.

An encapsulation of nitrogen and sulphur dual-doped carbon over Li[Ni0.8Co0.1Mn0.1]O2 for lithium-ion battery applications

Lithium ion batteries (LIBs) are considered as the competitive candidate for driving electric vehicles (EVs) and hybrid electric vehicles (HEVs). Among various cathode materials, nickel-rich layered Li[NixCoyMnz]O2 is particularly interesting due to its superior electrochemical performance. The Ni-rich layered cathode electrode material is regarded as an auspicious competitor for next-generation rechargeable LIBs due to the dominance of high theoretical capacity although it requires considerable improvements to achieve commercial success. Herein, we report a simple and one-step process to prepare nitrogen and sulphur dual-doped carbon (NSC) and subsequently coat over Ni-rich layered particles, NSC@Li[Ni0.8Co0.1Mn0.1]O2 (NSC@NCM811). The resulting 0.3 wt% of NSC@NCM811 delivers exceptional cycling stability than the pristine and other coated samples. At the end of 100 cycles, 0.3 wt% of NSC@NCM811 delivers the discharge capacity of 177.89 mAh g−1 at a current rate of 0.1C. With the advantage of exceptional electrochemical properties, 0.3 wt% of NSC@NCM811 is a promising alternative working electrode material for (LIBs).

Raising Lithium Storage Performances of NaTi2(PO4)3 by Nitrogen and Sulfur Dual-Doped Carbon Layer

NaTi2(PO4)3 as anode exhibits promising prospects in aqueous lithium ion battery due to the open frame and good stability. In this paper, N/S dual-doped carbon encapsulated NaTi2(PO4)3 nanoparticle (NTP@CNS) as anode for aqueous lithium ion battery has been successfully fabricated through sol-gel method followed by calcination treatment. Benefiting from the unique carbon layer doped nitrogen and sulfur, NTP@CNS shows excellent electrochemical property. It delivers discharge capacity of 119.4, 101.5, and 84.5 mAh g−1 at 0.5, 7.0, and 15 C, separately, increasing by 10, 30.5, and 51.2 mAh g−1 compared to original sample. Moreover, NTP@CNS demonstrates capacity retention of 83.4% after 1000 cycles at 6 C. The excellent property of NTP@CNS is because N/S dual-doping raises electronic conductivity of the sample, and also forms a lot of defects on the electrode surface. This can accelerate Li ion intercalation/deintercalation and electron transfer. N/S dual-doped carbon encapsulation for NaTi2(PO4)3 offers an efficacious and hopeful strategy to ameliorate electrochemical performance of anode.

Efficient carbon dioxide capture by nitrogen and sulfur dual-doped mesoporous carbon spheres from polybenzoxazines synthesized by a simple strategy

Nitrogen and sulfur dual-doped ordered mesoporous carbon has been synthesized from a novel polybenzoxazine using resorcinol, 2-aminothiazole, formaldehyde and different ampliphilictriblock copolymers by a simple one-pot strategy. The structure, morphology, and elemental compositions of the carbon was characterized using X-ray diffraction, raman spectroscopy, field emission scanning electron spectroscopy, and X-ray photoelectron spectroscopry. The effect of carbonization temperature, type of soft template and soft template concentration on the textural properties and CO2 adsorption capacity of porous carbon spheres has been studied. By varying the synthesis conditions, ordered mesoporous N, S dual-doped carbon with improved mesoporosity, specific surface areas of up to 910 m2/g and pore volume of 0.42 cm3/g were achieved. CO2 adsorption results revealed that the synthesized carbon possesses excellent performance as an absorbent for CO2 capture at 1.0 bar (4.25 and 3.17 mmol/g at 273 and 298 K, respectively). Apart from the micropores, presence of both nitrogen and sulfur elements are also necessary for achieving a high CO2 capture performance.

N,S-self-doped carbon quantum dots from fungus fibers for sensing tetracyclines and for bioimaging cancer cells.

In this work, nitrogen and sulfur dual-doped carbon quantum dots (N,S-CDs) from naturally renewable biomaterial fungus fibers were prepared by a biosynthesis and hydrothermal method. The N,S-CDs displayed good water solubility, excellent stability, high quantum yield (QY = 28.11%) as well as remarkable features for fluorescence quenching-based detection and cellular imaging of cancer cells. It was worth mentioning that the heteroatoms doped carbon quantum dots made from the fungus fibers had a satisfactory QY and could be used as a selective, efficient, and sensitive fluorescent probe to determine tetracyclines by the synergistic effects of static quenching and internal filtration effect. The probe demonstrated a wide linear range and low detection limit. For tetracycline, the linear range was 0.5 μM to 47.6 μM, and the corresponding detection limit was 15.6 nM. Significantly, the test papers prepared by using N,S-CDs could detect tetracyclines in aquiculture wastewater rapidly. The produced N,S-CDs did not affect the cell viability and showed great promises for cellular imaging.

Facile synthesis of nitrogen, sulfur dual-doped porous carbon via carbonization of coal tar pitch and MgCl2·6H2O for oxygen reduction reaction

Developing heteroatom-doped carbon catalysts toward oxygen reduction reaction (ORR) to replace platinum (Pt)-based catalysts is a promising strategy. Herein, nitrogen (N), sulfur (S) dual-doped porous carbons (NS@C-x-y) were prepared via a one-step carbonization of the mixture of acid treatment coal tar pitch (CTP) and MgCl2·6H2O, through in situ self-generating MgO template route. N and S were successfully introduced into the carbon framework of CTP by mixed acid treatment, leading to N, S co-doping especially pyridinic-N, graphitic-N, and C-S-C as ORR active sites. Benefiting from the fluffy lump graphitic structure, large surface areas, and synergistic effect between N and S electrocatalytic sites, the resulting samples demonstrate superior ORR performances with the highest diffusion-limited current density of 5.97 mA cm−2 and half-wave potential of 0.82 V (vs. RHE), long-term stability, and excellent methanol tolerance in alkaline medium, which are competitive with Pt/C catalyst.