Sulfur-doped Porous Carbon Research Articles

Sustainable supercapacitors of sulfur-doped carbon from environmentally friendly sodium lignosulfonate impregnated with bacterial cellulose

The use of sustainable natural sources to fabricate porous carbon materials has garnered significant interest in energy storage. This study proposes a method for synthesizing sulfur-doped porous carbon (S‑carbon) materials via the carbonization of bacterial cellulose (BC) impregnated with sodium lignosulfonate (LS), which functions as a renewable source of both carbon and sulfur, eliminating the need for external activation processes. The carbonization process yielded S‑carbon with a notable sulfur content of 1.4 % and a high specific surface area of 650 m2/g. Transmission electron microscopy (TEM) images reveal fibrous carbon structures with mesopores and micropores in the S‑carbon material. Electrochemically, S‑carbon exhibited an impressive specific capacitance of 272.6 F g−1 at a current density of 1 A/g and demonstrated outstanding cycling stability, retaining 86 % of its capacitance after 5000 cycles at a current density of 6 A/g in a 3 M KOH electrolyte. The development of sulfur-doped fibrous carbon from BC-LS offers promising potential as a sustainable electrode material for supercapacitors.

Facile fabrication of sulfur-doped porous carbon from waste sugarcane bagasse for high performance supercapacitors

Our research has led to a significant breakthrough in the field of energy storage. For the first time, we have prepared a series of highly porous sulfur-doped activated carbon derived from natural biomass sugarcane bagasse. The sulfur-doped waste sugarcane bagasse-derived activated carbon (WSC/S) possess a unique properties of large specific surface area (SSA) with high mesoporosity, better wettability, and numerous redox active dopant sites. These unique properties of WSC/S significantly enhance supercapacitor functionality. There are a large number of mesopores on the WSC/S, which shorten the ion diffusion path length and make their ion transport efficient. As the results of that the WSC/S achieved a high specific capacitance of 282.25 Fg−1 with a current density of 0.1 Ag−1 and excellent cycling stability with >96 % capacitance retention after 10,000 cycles in 6 M KOH electrolyte. We explored WSC/S as an anode material to fabricate an asymmetric supercapacitor (ASC) device, where activated carbon cloth was used as a cathode. The ASC device showed an energy density of 43.26 Wh kg−1 with a power density of 0.1 kW kg−1 at a current density of 0.1 Ag−1, which is superior to that obtained for symmetric WSC/S//WSC/S supercapacitor. These performances indicate the potential of the WSC/S for high-performance energy storage systems.

Ultra-Fast Synthesis of Highly Dispersed Pt Nanoclusters Anchored on Sulfur-Doped Porous Carbon Carriers by Nanosecond Pulsed Laser for Hydrogen Evolution Reaction.

Nanosecond pulsed laser irradiation is employed for synthesis of highly active and stable Pt-based electrocatalysts by anchoring Pt nanoclusters on porous sulfur-doped carbon supports (L-Pt/SC). Strong metal-support interaction (SMSI) between Pt and S induces a local charge rearrangement and modulates the electronic structure of Pt surroundings, thus boosting the reaction kinetics and enhancing stability in long-term hydrogen evolution reaction (HER). The L-Pt/SC catalyst exhibits high activity toward HER, with an overpotential of 23 mV at current densities reaching 10 mA cm-2 and a Tafel slope of 24mV dec-1. The unit mass activity of L-Pt/SC is calculated to be -10.8 A cm-2 mgPt -1 at an applied voltage of -0.3V versus RHE. In situ Raman spectra reveals that L-Pt/SC catalyst exhibits fast hydrogen production efficiency and its electrocatalytic HER process is determined by the Tafel step. Density functional theory calculations suggest the strong bonding energy between SC and Pt induces the formation of smaller nanoclusters of L-Pt/SC during fast pulsed laser preparation, which increases the effective contact area during the HER process thereby increasing the activity per unit mass.

Selective electrosorption of heavy metal ions from wastewater with S-doped hierarchical porous carbon derived from waste Camellia oleifera shell

Capacitive deionization (CDI) has garnered significant attention in desalination and the removal of heavy metal ions. The quest for cost-effective and high-performance electrode materials is crucial to advance CDI applications. Herein, we report a sulfur-doped hierarchical porous carbon (SPC) derived from waste camellia oleifera shells via a sustainable hydrothermal carbonization process followed by KOH/ammonium salt activation. The optimized SPC-0.2 exhibits exceptional characteristics, featuring a high specific surface area of 1875 m2 g−1 and substantial sulfur doping at 8.65 %, leading to enhanced specific capacitance (161.3 F g−1) in a 1 M NaCl solution. Under optimal operating conditions (1.2 V, 10 mL min−1, 500 mg L−1 NaCl), the SPC-0.2 electrode achieves a notable desalination capacity of 26.64 mg g−1. In particular, the electrode can selectively remove >99 % of Cr3+ and Cu2+ ions (each 10 mg L−1) in a 100 mg L−1 NaCl solution. This high selectivity is attributed to the formation of sulfides via low adsorption energies between the doped sulfur atoms and the targeted heavy metal ions. Furthermore, the SPC-0.2 electrode demonstrates robust reusability and high efficiency in the actual water body. Collectively, our findings underscore the significant potential of the synthesized SPC as an electrode material for CDI, particularly in the selective capacitive removal of heavy metal ions from wastewater. This work not only contributes to the circular economy by using waste biomass, but also offers a viable solution for environmental remediation.

Ice template-induced assembly coupled with carbonization strategy for preparation of sulfur-doped porous carbon nanosheets from lignite as high-capacity anode for lithium-ion batteries

Two-dimensional (2D) porous carbon nanosheets with heteroatom doping are promising anode materials for lithium-ion batteries (LIBs) due to their distinctive sheet-like structure and excellent electrical conductivity. Limited by high preparation costs and cumbersome preparation processes, the large-scale production of carbon nanosheets remains a major challenge. Herein, a series of sulfur-doped porous carbon nanosheets (SCNSs) are successfully synthesized through ice template-induced assembly coupled with a carbonization approach using aromatic ring fragments exfoliating from lignite as the precursor and K2SO4 as the sulfur source. The prepared SCNSs exhibit well-defined sheet-like structures, abundant hierarchical nanopores, large specific surface areas (∼1761 m2·g−1), and high sulfur doping contents (∼7.72 at%). Such unique microstructure characteristics of SCNSs not only provide favorable and efficient channels for the lithium-ions/electrons transportation but also offer sufficient available space or active sites for lithium-ions storage. When used as anode materials for LIBs, the SCNS-3 shows high reversible capacity (1620 mAh·g−1 at 0.05 A·g−1), excellent rate performance (315 mAh·g−1 at 2 A·g−1), and superior cycling stability (901 mAh·g−1 at 1 A·g−1 after 500 cycles). Lithium storage behavior analysis indicated that the capacitance enhancement in SCNSs anodes is primarily due to improved capacitive behavior. This study provides a novel and effective route for the large-scale production of sulfur-doped carbon nanosheets using aromatic ring fragments exfoliated from lignite, which demonstrates promising industrial application potential in LIBs anode materials.

Dual Doping of Sulfur and Nitrogen Induces Hierarchical Porous Carbon from Wastes Medical Masks for Supercapacitor Electrodes

Demand for battery and supercapacitor materials rapidly increases as energy storage deployments accelerate. Waste-based supercapacitors have become a point of interest to accommodate growing demand and awareness of environmentally friendly products. This work aims to examine how doping with sulfur and nitrogen affects the morphology and structure of porous carbon synthesized from waste medical masks and the electrochemical performances of the prepared electrodes. Nitrogen- and sulfur-doped porous carbon (a-C:NS) is successfully obtained by solvothermal and hydrothermal processes in an autoclave followed by chemical activation using potassium hydroxide (KOH) and a carbonization procedure. Sulfur- and nitrogen-doping increase the yield compared to the directly carbonized process of the waste medical mask. The a-C:NS sample has a porous feature, showing the presence of S, N, O, and dominant C elements and the formation of C-S and C-N bonds. The supercapacitor electrode prepared from a-C:NS shows an electric double layer capacitor (EDLC)-like characteristic with a high specific capacitance (CS) of 300 F/g at the scanning rate of 5 mV/s. This study shows a possible route to transform polypropylene waste into functional materials for supercapacitor electrodes.

Synthesis Routes of Sulfur-doped Porous Carbon from Mask Wastes for the Application of Supercapacitor Electrodes

Abstract Increasing demand of energy storage devices stimulates growing research in supercapacitors technologies. Waste-based supercapacitor electrodes has become one of areas to be explored as they offer an environmentally friendly approach. Here we synthesis porous carbon from wastes of medical masks which have been generated a lot since the pandemic. Medical masks are composed of polypropylene which have high porosity; hence they have a potential to be used as a porous carbon source for supercapacitor applications. The synthesis routes include a solvothermal process inside a Teflon autoclave in a microwave and a washing process using dilute acid solution and distilled water. The routes successfully transform polypropylene to porous carbon, confirmed by XRD, FTIR, SEM-EDX and Raman spectrum analyses. The present of C-S bond are indicated from FTIR spectrum, implying a successful doping of sulphur into porous carbon. The electrochemical analysis of the prepared electrode using cyclic voltammetry shows an EDLC-like feature with high specific capacitance of ∼375 Fg−1 at the scan rate of 5 mV/s.

Biomass-derived sulfur-doped porous carbon for CO2 and CH4 selective adsorption

Series of sulfur-doped porous carbons were prepared by using glucose as carbon source and sodium dodecyl sulfate as sulfur source to synthesize sulfur-based carbon precursor and KOH as activator. Pore structure parameters and sulfur content of the prepared carbon materials could be facility regulated by controlling the ratio of KOH/sulfur-based carbon precursor and activation temperature, and their adsorptive separation properties towards CO2 and CH4 were investigated. Results showed that the higher the ultra-microporous volume and the S content of the prepared sulfur-doped porous carbon were, the larger the CO2 and the CH4 adsorption capacity were. The maximum adsorption capacity of CO2 (6.54 mmol/g, 273.15 K and 101 kPa, hereinafter) and CH4 (2.98 mmol/g), and the excellent selectivity of CO2/N2 (75.7) and CH4/N2 (22.8) were achieved by ACS-700-2 because of its higher ultra-microporous pore volume and the highest S content. Permeation experiment, cycle stability test and adsorption thermodynamics experiment show that the prepared S-doped porous carbon had good application potential in the separation and enrichment of CO2 in flue gas and CH4 in coalbed methane. In addition, the pore formation mechanism of sulfur-doped porous carbon was discussed.

Chitosan-derived carbon sphere with self-activating behavior for stable oxygen reduction reaction in acid and alkaline media

Utilizing shrimp waste-derived Chitosan as biomass source, we developed metal-free nitrogen and sulfur-doped porous carbon (NSPC) with a high specific surface area of 609.53 m2/g as a remarkable electrocatalyst for oxygen reduction reaction (ORR), surpassing benchmark Pt/C with half-wave (0.8574 V) and onset (0.9573 V) potentials in alkaline (0.1 M KOH) media. Besides high electrocatalytic activity, NSPC-800 showed excellent methanol tolerance ability and significantly low hydrogen peroxide yields (H2O2) of 5 % and 8 % in 0.1 M KOH and 0.5 M H2SO4, which is comparably lower than the previously reported chitosan based non-precious catalysts. Interestingly NSPC-800 displays robust stability in 0.1 M KOH electrolyte, improving the current retention rate from 89.17 % to 95.18 % over an increased operation period, evidencing its self-activating characteristics. This self-activating stability is also mirrored in 0.5 M H2SO4 where both fresh and recycled (after 5000 CV cyles) NSPC-800 catalysts retained more than half of their initial current. Additionally, to identify the nature of the active sites, the ORR measurements were correlated with ex-situ spectroscopy for post-stability of fresh and recycled NSPC-800 catalysts revealed dynamic reconfiguration of nitrogen, sulfur, and oxygen active sites evidenced compared to the pre-stability elemental surface, indicating an adaptive response of the catalyst to the harsh operating environment. In the future, our biomass-derived NSPC-800 will pave the way to develop cost-effective and highly efficient catalysts from waste to energy devices promising a twin-goal approach, contributing to the circular economy and sustainable development goals.

Copper oxides supported sulfur-doped porous carbon material as a remarkable catalyst for reduction of aromatic nitro compounds

Synthesis and manufacturing of metal–organic framework derived carbon/metal oxide nanomaterials with an advisable porous structure and composition are essential as catalysts in various organic transformation processes for the preparation of environmentally friendly catalysts. In this work, we report a scalable synthesis of sulfur-doped porous carbon-containing copper oxide nanoparticles (marked CuxO@CS-400) via direct pyrolysis of a mixture of metal–organic framework precursor called HKUST-1 and diphenyl disulfide for aromatic nitro compounds reduction. X-ray diffraction, surface area analysis (BET), X-ray energy diffraction (EDX) spectroscopy, thermal gravimetric analysis, elemental mapping, infrared spectroscopy (FT-IR), transmission electron microscope, and scanning electron microscope (FE-SEM) analysis were accomplished to acknowledge and investigate the effect of S and CuxO as active sites in heterogeneous catalyst to perform the reduction-nitro aromatic compounds reaction in the presence of CuxO@CS-400 as an effective heterogeneous catalyst. The studies showed that doping sulfur in the resulting carbon/metal oxide substrate increased the catalytic activity compared to the material without sulfur doping.

Preparation of inexpensive S-doped porous carbons for high-performance supercapacitors

Low-cost sulfur-doped porous carbons were prepared through hard template method by using inexpensive colloidal SiO2 nanoparticles as template, glucose as carbon source, H2SO4 as pre‑carbonized reagent and sulfur source. The effects of H2SO4 and carbonization temperature on the microscopic morphology, the pore structure and the specific surface area of porous carbons were explored through multiple characterization methods. The capacitive performance of porous carbons was investigated by multiple electrochemical methods. It was found that the pore structure, specific surface area and the content of sulfur element of carbon are highly dependent on the carbonization temperature. The sulfur-doped porous carbon SPC-900 has much larger surface area and larger pore volume, and thus much better capacitive performance than un-doped PC-900, indicating that H2SO4 can increase the surface area and the pore volume during the preparation process. SPC-900 offers the advantages of lower cost, larger pore size, higher pore volume, better capacitive performance and better rate performance compared to expensive mesoporous carbon CMK-3. In the three-electrode system, the specific capacitance of SPC-900 can reach 363 F g−1, whereas that of PC-900 is only 164 F g−1 at a current density of 0.5 A g−1. The double layer capacitance (EDLC) and pseudocapacitance can both be increased by the sulfur element, according to the capacitive contribution study. Additionally, the SPC-900 can maintain its initial specific capacitance of 98.1 % for 10,000 cycles at a current density of 0.5 A g−1, demonstrating both its high cycling performance and potential for practical applications.

Sulfur-doped activated carbon for the efficient degradation of tetracycline with persulfate: Insight into the effect of pore structure on catalytic performance.

Sulfur-doped activated carbon has proved to be a promising metal-free catalyst for persulfate (PDS) catalytic activation for the oxidation of aqueous refractory organics. Herein, sulfur-doped porous carbon (ACS) catalysts with different pore structures and doped-S contents were prepared via a template method using d(+)-glucose as the carbon source, sulfur as the sulfur source, and nano-MgO with different particle sizes as templates. Characterization results showed that the particle size of MgO significantly affects the pore structure and doped-S content of ACSs catalysts: a sample synthesized with 20 nm MgO as template (ACS-20) presented the highest content of doped-S and a mesoporous structure, which endowed it with superior adsorption and catalytic performance toward tetracycline (TC) removal. The effect of catalyst dosage, TC concentration, PDS concentration and solution pH on TC removal efficiency were evaluated. The reaction mechanism, investigated by combination of EPR, quenching experiments and LC-MS, indicated that the reactive species included HO·, SO4˙-, and 1O2, but that 1O2 played the dominant role in TC oxidation through a non-radical oxidation pathway. In addition, the reusability and regeneration properties of the ACS-20 catalyst were also studied. This work provides a promising strategy and some theoretical basis for the design and preparation of activated carbon catalysts for advanced oxidation reactions from the viewpoint of pore structure design and S-doping.

Sulfur-doped porous carbon sheets embedded with rich iron sites for 1O2 dominated peroxymonosulfate activation

Porous carbon films co-doped with iron, nitrogen, and sulfur were synthesized via a one-step pyrolysis process, which have multiple active sites and can produce bulk 1O2 through PMS activation, which is effective in phenol degradation.

Sulfur-Doped porous carbon Adsorbent: A promising solution for effective and selective CO2 capture

The effective and selective capture of CO2 through the rational design of microstructures and the synthesis of carbon materials with enriched surface functionality is of utmost importance in mitigating CO2 emissions. In this study, we successfully prepared a novel type of S-doped porous carbon material with a high surface area and a significant volume of micropores in a straightforward manner. This was achieved by pyrolyzing carbonized coconut shells (CS) with potassium thiosulfate K2S2O3 (PT) as an activating and sulfur supply agent. By adjusting the pyrolysis temperature within the range of 650–750 °C, we obtained carbon materials with varying surface areas (887–1924 m2/g), pore volumes (0.35–0.95 cm3 g−1), and a homogeneous distribution of sulfur content (up to 12.26 wt%) within the carbon framework. The optimal S-doped porous carbon demonstrated the adsorption capacities of 3.59 mmol g−1 at 25 °C and 5.31 mmol g−1 at 0 °C under 1 bar. Additionally, the prepared sorbent exhibited favorable CO2/N2 selectivity, high isosteric heat, and stable cycling performance. These excellent CO2 capture properties can be attributed to the materials' high microporosity and well-dispersed sulfur functionality in the carbon framework. Collectively, these findings highlight the potential of these novel carbon materials with heteroatom doping as efficient adsorbents for the selective capture of CO2, presenting a viable solution in the quest for effective CO2 mitigation.

Sulfur-doped hollow porous carbon spheres as high-performance anode materials for potassium ion batteries

Sulfur-doped hollow porous carbon spheres as high-performance anode materials for potassium ion batteries

Bimetallic zeolitic imidazole framework-derived sulfur-doped porous carbon as highly efficient catalysts for oxygen reduction reaction in proton exchange membrane fuel cells

The oxygen reduction reaction (ORR) is the most sluggish half-reaction in fuel cells; therefore, Pt-group metal (PGM)-based electrocatalysts have been employed to circumvent this limitation. However, the use of Pt, which is a precious metal, significantly limits the commercialization of proton-exchange membrane fuel cell (PEMFC) systems because of the high cost and low durability of Pt-based materials. Herein, we introduce advanced S-doped Co–N–C (CoNC) porous electrocatalysts (S-CoNPCs) derived from zeolitic imidazole frameworks as substitutes for PGM-based electrocatalysts. To improve the electrocatalytic activity of CoNC, sulfur doping, and acid etching treatment methods, which are innovative procedures, are employed to obtain high catalytic activity and a large surface area. S-CoNPC demonstrates an extremely improved electrochemical performance for ORR in both alkaline and acidic mediums compared with commercial Pt/C, exhibiting Eonset, E1/2, and limiting current density of approximately 0.91 V, 0.85 V, and −6.7 mA cm−2 (at 0.40 V vs. RHE), respectively, which are in the suitable range for commercializing the PEMFCs system. Furthermore, S-CoNPC, which exhibits high selectivity, stability, and methanol tolerance, is a promising, novel, and advanced non-PGM electrocatalyst for diverse applications.

Carbon nanotube supported zinc, cobalt, nitrogen, sulfur-doped porous carbon as electrocatalyst for enhanced oxygen reduction reaction

Carbon nanotube (CNT) supported zinc, cobalt, nitrogen, sulfur-doped porous carbon (CNT@ZnCo/NSC) catalysts are prepared by in situ growth of sulfur-containing bimetal zeolitic imidazolate framework (S–ZnCo-ZIF) polyhedrons on CNT with subsequent heat treatment. The microstructure, morphology, particle size distribution, specific surface area, and pore-size distribution of the catalysts are characterized by multiple techniques. CNT@ZnCo/NSC exhibits excellent catalytic activity for oxygen reduction reaction (ORR) with onset potential of 0.98 V and half-wave potential of 0.83 V, respectively, which are close to those of Pt/C. The addition of CNT inhibits the agglomeration and improves the conductivity of the catalysts, while S doping enhances the electrochemical surface area and introduces active sites. The special structure makes CNT@ZnCo/NSC possess proper specific surface area (390.8 m2 g−1) and large average pore size (5.26 nm). CNT@ZnCo/NSC contains more graphite-N (21%) and pyridine-N (55.9%) than CNT@ZnCo/NC (20%, 46.5%) and ZnCo/NC (8.2%, 45.8%). CNT@ZnCo/NSC catalyst has better methanol tolerance and long-term stability than commercial Pt/C.

Selective Adsorption and Recovery of Silver from Acidic Solution Using Biomass-Derived Sulfur-Doped Porous Carbon.

It is vital to recycle precious metals effectively such as silver from waste sources because of limited natural reserves. Herein, passion fruit (Passiflora edulis Sims) shell-derived S-doped porous carbons (SPCs) were newly synthesized by hydrothermal carbonization and following with activation by KOH/(NH4)2SO4, and the adsorption of Ag+ on SPC under acidic solutions was investigated. It was found that the activator of (NH4)2SO4 can not only introduce the doping of S elements but also increase the proportion of mesopores in the as-prepared SPC. As the active site, the increasing S doping can improve the adsorption of Ag+ on SPC. The kinetic data of Ag+ adsorption by SPC was consistent with the pseudo-second-order kinetic model. The Langmuir isothermal model was used to well fit the Ag+ adsorption isotherms of SPC, and the maximum adsorption capacity of the optimized SPC-3 for Ag+ is up to 115 mg/g in 0.5 mol/L HNO3 solution. SPC-3 showed good selectivity toward Ag+ over diverse competing cations, which is mainly attributed to the strong bonding between Ag+ ions and the sulfur-containing functional groups on the surface of SPC-3 resulting in the formation of Ag2S nanoparticles. The adsorbed Ag could be recovered as an elemental form by a simple calcination. This study provides a new insight into the design of an environmentally friendly and efficient adsorbent for the selective recovery of silver from acidic aqueous media.

High sulfur-doped microporous carbon for high-rate potassium ion storage: Interspace design and solvent effect

Carbon materials as promising anode for potassium ion batteries (PIBs) suffer from low rate performance, which is attributed to sluggish K+ transport stemming from limited carbon interspace and elusive solvent effect. Herein, interspace design and solvent effect are investigated to resolve this issue. Through an innovative salt template assisted molten sulfur method, large hollow pores, massive micropores and expanded interlayer spacing are integrated in a high sulfur-doped porous carbon (S-PC), showing obviously higher rate capability (351.5 and 122.3 mA h g−1 at 0.1 and 20 A g−1, respectively) than pristine porous carbon (PC). Furthermore, the S-PC exhibits significantly-higher rate performance in ester-based electrolyte (1 M KFSI/EC + DEC) than in ether one (1 M KFSI/DME). Kinetic study demonstrates advantage of interspace design and ester-based electrolyte on promoting faster K+ transport. The explicit solvent effect on S-PC is further examined by XPS and HRTEM analyses, revealing a desirable inorganic KF-salt-dominated, thin solid electrolyte interface (SEI) layer in ester-based electrolyte. This work opens new avenues for precise design of advanced carbon materials for high-rate PIBs.

Sulfur-doped SnO2 nanoparticles encased in porous carbon derived from a metal-organic framework for lithium-ion battery anodes

Anodes for lithium-ion batteries that are made of Sn-based materials are thought to be promising because they have a low operating voltage and a high theoretical capacity. Unfortunately, cycling causes a large expansion in volume, which quickly lowers capacity. We propose sulfur-doped porous carbon skeleton nanoparticles with SnO2 incorporated using a metal organic framework (MOF) technique (Sn@C-800). In addition to minimizing SnO2 particle aggregation and volume expansion, the enhanced stability of the carbon network prevents encapsulated SnO2 from coming into contact with the electrolyte. The inclusion of sulfur also increases the electrical conductivity of the material and provides sites for lithium-ion storage actives. The Sn@C-800 has a high-rate capacity of 1067 mAh g−1 of 0.1 A g−1 and a remarkable cycle performance of 1188 mAh g−1 at 1.0 A g−1. After 1000 cycles, the reversible capacity increases to 637 mAh g−1. This paper proposes a method for producing Sn-based LIBs anode materials with outstanding performance.