Heteroatom-doped Carbon Research Articles

Mitigating Zinc Dendrite Formation and Parasitic Side Reactions in Aqueous Zn-Ion Batteries Via Laser-Assisted Carbonization of Cu-PANI Films on Zn Anodes.

Aqueous zinc-ion batteries (ZIBs) are gaining attraction for large-scale energy storage systems due to their high safety, significant capacity, cost-effectiveness, and environmental friendliness. On the other hand, the development of aqueous ZIBs is restricted by the limited practical application of zinc (Zn) because of the high reactivity of Zn in aqueous electrolytes, which results in the severe dendrite growth and parasitic side reactions such as hydrogen evolution reaction (HER). In this study, heteroatom-doped carbon porous surface modification by laser-assisted carbonization of copper (Cu) doped polyaniline (PANI) is designed and fabricated on top of the Zn metal anode (c-Cu-PANI/Zn). The c-Cu-PANI surface-modified Zn anodes exhibit high electrochemical stability and performance during the Zn plating-stripping cycles and suppress the dendrite formation. The symmetrical cell and half-cell with the c-Cu-PANI/Zn anodes exhibit stable cycles for 6000h and 100% Coulombic efficiency for 2500 cycles, respectively. Moreover, the c-Cu-PANI/Zn║V2O5 cell delivers a high specific capacity of 319 mAh g-1 at 0.2 A g-1, which is significantly higher than that of the bare Zn║V2O5 cell (240 mAh g-1). It is believed that applying c-Cu-PANI as a surface modification can enhance the stability and reversibility of the Zn anodes, therefore accelerating the commercialization of ZIBs.

Enhanced electrochemical oxygen reduction reaction on “C–O–Si” bonds in Si-doped graphene-like carbon

The use of heteroatom-doped carbon materials as non-precious metal catalysts for oxygen reduction reactions has attracted much attention from researchers. This paper presents the synthesis of two-dimensional Si-doped graphene-like materials (Si-GLC) featuring “C–O–Si” bonds through an in-situ doping method. Since the electronegativity of the Si (1.90) is much smaller than that of C (2.55) and O (3.44), the formation of the “C–O–Si” bond causes Si to lose a large number of electrons and become positively charged. This increases the adsorption of electronegative oxygen, thereby improving the activity of oxygen reduction reactions. The adsorption energy of oxygen molecules on Si-GLC was calculated to be −3.57 eV using density functional theory, much lower than on GLC (−2.18 eV). This suggests that Si doping enhances the adsorption of oxygen molecules by graphene-like materials, which is crucial for improving the performance of oxygen reduction reaction. Si-GLC displayed a half-wave potential of 0.80 V (vs. RHE) and a diffusion-limited current density of 5.81 mA cm−2 in 0.1 M KOH solution, demonstrating excellent catalytic activity for oxygen reduction reaction. It also exhibits good stability and tolerance to methanol crossover effect. In-situ doping creates “C–O–Si” bonds, modulating charge density and providing a strategy for high-performance oxygen reduction catalysts.

Co–Ni nanoparticle supported on heteroatom-doped carbon derived from garlic powder and eutectic solvent: Its application in Nitroarenes reduction

This paper presents the synthesis of a novel heterogeneous catalyst, PSN-C600-Co2:Ni1, designed for the hydrogenation of nitroaromatic compounds. The catalyst is a porous carbon substrate triply doped with nitrogen, sulfur, and phosphorus, incorporating bimetallic Co and Ni nanoparticles. A natural precursor, garlic biochar, and a biodegradable eutectic solvent were used in the synthesis. Various characterization techniques, including Scanning Electron Microscope (SEM), X-Ray Energy Diffraction Spectroscopy (EDX), Elemental Mapping Measurements (MAP), Thermogravimetric Analysis (TGA), X-Ray Diffraction (XRD), Infrared Spectrometer (FTIR), Transmission Electron Microscope (TEM), Raman Spectroscopy, and Nitrogen Adsorption and Desorption Pattern (N2 adsorption-desorption isotherm), were utilized to examine the features and properties of the synthesized PSN-C600-Co2:Ni1 catalyst.

Elucidating the efficacious capacitive deionization defluorination behaviors of heteroatom-doped hierarchical porous carbon nanofibers membrane

Heteroatom-doped porous carbons, particularly those incorporating nitrogen functionalities, demonstrate exceptional electrochemical properties advantageous for capacitive deionization (CDI) defluorination. Nevertheless, the underlying mechanism of fluoride removal remains inadequately understood, warranting comprehensive investigation to facilitate the practical implementation of CDI technology. Herein, a novel nitrogen-doped hierarchical porous carbon nanofiber membrane (HPCNM) derived from a hydrochloric acid etched FeNi3@CNFs (FeNi3 alloy encapsulated within carbon nanofibers) network was reasonably designed and synthesized for CDI defluorination. The HPCNM electrode exhibited superior defluorination capabilities, attributed to its distinctive hierarchical porosity and compositional architecture. The novel material achieves remarkable performance metrics, including a defluorination capacity of 58.38 mg g−1, rapid ion removal kinetics (0.97 mg g−1 min−1), and maintained efficiency throughout 20 operational cycles. Density functional theory (DFT) calculations indicate that nitrogen-doped carbon (NC) preferentially adsorbs fluoride, exhibiting the lowest adsorption energy. Fluoride interacts with NC through a combination of weak covalent bonds and van der Waals forces. Its inherent electronegativity, hardness, and high electrophilicity index, contrasted with low softness and nucleophilicity, facilitate the selective adsorption. Furthermore, an optimized NC electrode, operating at 1.2 V in simulated industrial wastewater, achieved fluoride removal compliant with national standards, demonstrating its practical applicability for treating contaminated effluent. These findings advance the understanding of selective fluoride removal, contributing to the development of targeted electrodes for industrial applications.

Double alkali metal salts synergistic activation coupled with S-doped cotton derived honeycomb porous carbon for enhanced zinc ion storage capability

Biomass-derived carbon materials are ideal electrode materials due to their inherent eco-friendliness, easily available and unique micro-morphology. Herein, zinc ion capacitors (ZICs) are designed utilizing S doped honeycomb porous carbon nanosheet cathode, which is obtained via synergistic activation from sodium thiosulfate and potassium carbonate. The honeycomb microstructure is result from the pore-forming effect of double alkali metal salts, which can promote the electrolyte ion fast migration in the cathode. Besides, the S doping in carbon array can regulate the electron distribution within the carbon framework and lower the energy barrier for the chemical absorption of Zn2+/H+, which is demonstrated by density functional theory calculation and expected to produce additional capacitance. Further, the ex-situ X-ray photoelectron spectroscopy reveals the consistent changes in C-O-H and C-O-Zn throughout the charging and discharging cycles, which demonstrate the S doping can promote the reversible chemical adsorption and desorption reaction of Zn2+/H+. As a result, the S doping honeycomb porous carbon nanosheet cathode can achieves a high discharge capacity of 147.2 mAh g−1 and high energy density of 92.7 Wh kg−1. Additionally, the obtained material exhibits good cycling stability at 20 A g−1, retaining 99.9 % of its initial capacity after 2000 cycles. This research presents a versatile approach to synthesizing heteroatom-doped carbon materials from biomass waste for ZICs.

N, P Co-Doped Hard Carbon Anodes for High-Performance Lithium-Ion Batteries with Enhanced Capacity Retention and Cycle Stability.

Compared to the traditional graphite anode, heteroatom-doped polymer carbon materials have high capacity retention due to their high porosity and porous structure. Therefore, they have great potential for application in lithium-ion battery (LIB) anodes. In this work, an N, P co-doped precursor polymer material (MBPp), synthesized via a one-pot method using bisphenol-A (C-source), melamine (N-source), and 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (P-source). The resulting N, P-co-doped hard carbon materials (MBPs) were prepared at various pyrolysis temperatures, yielding microporous, mesoporous, and macroporous structures. MBP materials demonstrated excellent electrochemical performance as LIB anodes. Notably, MBP-900 achieved a reversible capacity of 262 mAh g-1 at 1000 mA g-1 (in 0.005-2.0 V voltage range) with a capacity retention rate of 97.1 % after 1000 cycles. These findings highlight the significance of MBP materials, which possess numerous defects, large layer gaps, and excellent cycle stability, in advancing the development of polymer anode materials for LIBs.

Revealing the Effect of Curvature Structure in Hard Carbon Anodes for Lithium/Sodium Ion Batteries.

Heteroatom doping is the most common means to enhance the Li+/Na+ ions storage of hard carbon (HC). The explanation of the storage mechanism of heteroatom-doped HC is to increase the active site or widen the layer spacing while ignoring the effect of local bending structure induced by it. Meanwhile, the storage mechanism by the localized bending structure also lacks in-depth study. Herein, a locally curved configuration and an amorphous structure are designed by introducing different heteroatoms, respectively, and the mechanism of the two types of structures on the Li+/Na+ ions storage is explored. The density functional theory (DFT) calculation shows that the adsorption energy of Li+/Na+ ions is optimal at the appropriate curvature of 27.72 m-1. Serving as anode for lithium/sodium ion batteries in ester electrolytes, the optimized HCs demonstrate satisfied specific capacity and high-rate capability, respectively. Furthermore, the charging capacity below 1.0V of HC with suitable curvature microstructure reaches 84.8% and 90.1% of the total charge capacity, confirming that the curvature defects can better control the delithiation/desodiation process, and provide a higher energy density. This study enlightens new insights into the storage mechanisms of Li+/Na+ ions and provides guidance for better design of heteroatom-doped carbon anodes with superior performance.

Covalent Organic Framework Derived Oxygen/Sulfur-Doped Porous Carbon for Robust High-Capacitance Symmetric Supercapacitors.

Heteroatom-doped porous carbons (HPCs) have been considered promising electrode materials for supercapacitors due to their improvement of energy density by providing extra pseudocapacity. Covalent organic frameworks (COFs) are obtaining great importance in energy storage because of their designable structure and versatile functionality. Herein, we designed and fabricated oxygen and sulfur dual-doped covalent organic framework (COF) derived HPCs with very high heteroatoms content (up to 25.76 atom%) via a facile coupling reaction. The optimized HPCs exhibit a porous structure with high specific surface area (up to 2835 m2 g-1) along with a high specific capacitance (430 F g-1 at 0.5 A g-1), excellent capacitance retention (96.9%), and high coulombic efficiency (98.5%) after 10000 cycles at 5 A g-1. As electrodes for aqueous symmetric supercapacitors, the HPCs exhibits a high energy density of 60 Wh kg-1 at a 250 W kg-1 power density, excellent cycling stability of capacity retention (82.2%) and a high coulombic efficiency (92.3%) after 10000 cycles at 10 A g-1, indicating attractive application potential in chemical energy storage. This work establishes a promising strategy for preparation of high heteroatom content HPCs using COFs and demonstrates great potential for energy storage/conversion devices.

Nitrogen and Sulfur Doped Porous Carbon Sheet with Trace Amount of Iron as Efficient Polysulfide Conversion Catalyst for High Loading Lithium-Sulfur Batteries.

The major challenges in enhancing the cycle life of lithium-sulfur (Li-S) batteries are the polysulfide (PS) shuttling and sluggish reaction kinetics (S to Li2S, Li2S to S). To alleviate the above issues use of hetero atom doped carbon as cathode host matrix is a low-cost and efficient approach as it works as a dual-functional framework for PS anchoring as well as electrocatalyst for faster redox kinetics. Here, the dual role of the Fe-containing heteroatom-doped carbon sheets (CS) in chemisorption of Li2S6 and catalyzing its faster conversion to Li2S is established through UV-Vis, XPS and CV studies. To substantiate the catalytic effect composite cathodes were prepared by encapsulating sulfur in CS which is further blended with carbon nanotubes (CNTs) to form free-standing cathode. The electrochemical performance of the three cathodes viz., S@Fe-N-CS-CNT, S@Fe-S-CS-CNT and S@Fe-NS-CS-CNT were evaluated by constructing Li-S cells. Among all, the S@Fe-NS-CS-CNT delivers a high initial discharge capacity of 1017 mAh g-1 at 0.5 C rate and sustains 751 mAh g-1 capacity after 260 cycles with a capacity retention of 73.8 %. Even at high S-loading (12 mg cm-2), it delivers an initial discharge capacity of 892 mAh g-1 and it retained 575 mAh g-1 after 200 cycles.

Heterointerfacial engineering of N,P-doped carbon nanosheets supported Co/Co2P nanoparticles for boosting oxygen reduction and oxygen evolution reactions towards rechargeable Zn-air battery

Transition metal phosphides (TMPs) with high electrocatalytic activity for the oxygen evolution reaction (OER) are reckoned as a substitution of precious group metals catalysts in rechargeable Zn-air battery. In this work, Co/Co2P heterojunction nanoparticles supported N,P-doped carbon nanosheets (Co/Co2P@NPCNS) were designed and prepared via a facile one-step molten salt-assisted pyrolysis process. Density function theory calculations reveal that the heterogeneous interactions of Co/Co2P effectively enhance the bifunctional electrocatalytic activity for oxygen reduction reaction (ORR) and OER. The synergistic interaction between the Co/Co2P heterojunction nanoparticles with highly exposed active sites and excellent catalytic activity and the two-dimensional doped carbon nanosheets with high conductivity contributes to Co/Co2P@NPCNS exhibiting preeminent bifunctional ORR/OER activity and stability with a high half-wave potential for ORR (0.87 V), a low overpotential for OER (302 mV at 10 mA cm−2) and a low potential gap (0.66 V). The homemade rechargeable Zn-air battery performs high peak power density (187 mW cm−2) and exceptional endurance. This heterogeneous interface tactic of integrating TMPs with heteroatom-doped carbon materials may shed light on the research and development of non-precious metal electrocatalysts.

Poly(aniline-2-sulfonic acid-co-aniline) modified nickel-doped carbon catalyst for power generation in microbial fuel cells

Microbial fuel cells (MFCs) are self-powered devices used for power generation. However, the advancement of the technology is hindered poor durability, sluggish electrochemical reaction kinetics, and high capital costs, especially for cathode materials. In this study, we developed a nickel (Ni) chelate catalyst derived from thiourea-formaldehyde resins (Ni-TF), which incorporates sulphur (S) and nitrogen (N) groups, to enhance the oxygen reduction reaction (ORR) kinetics. To improve the electrical conductivity and electron transfer and to investigate the influence of N and S content, Ni-TF particles were interwoven with polyaniline and aniline-2-sulfonic acid-co-aniline, respectively. The integration of self-doped electroactive polymer with Ni-TF significantly enhanced the catalytic activity of the resulting composite (SPAN-PAN/Ni-SNC). SPAN-PAN/Ni-SNC exhibited a high oxygen reduction potential of 0.335 V (vs. RHE) at −0.018 mA, superior stability, and a low charge transfer resistance of 95.1 Ω. Furthermore, SPAN-PAN/Ni-SNC recorded a maximum power density of 2045.1 mW m−2 at a current density of 8343.8 mA m−2, compared to 873.67 mW m−2 and 5453.6 mA m−2 for Ni-SNC. This improvement is attributed to the synergy between the interwoven Ni-SNC and conducting copolymer. These findings indicate that encapsulating metal-doped catalysts within heteroatom-doped carbons can enhance long-term fuel cell performance and related applications.

Metal organic framework derived heteroatom doped porous carbon nanocubes enable efficient charge storage in a lithium-ion capacitor

Lithium-ion capacitors (LICs) are regarded as one of the promising technologies towards realizing energy & power dense energy storage systems. However, their energy densities at higher power densities are still limited due to the discrepancy between electrode kinetics of capacitor-like cathode and battery-like anode. Developing carbon materials with well-defined structures, porosity to match the chemical kinetics between electrodes are the major challenges to overcome. In the present work, we have devised a strategy to fabricate S, N dual-doped porous carbon nanocubes (S, N-PCNs) using zeolitic imidazole framework (ZIF)-8 precursors, and employed the PCNs as anode material in LICs. With its well-defined structure, hierarchical porous nature, and abundant heteroatom presence (1.9 % S, 16.2 % N), the pre-lithiated S, N-PCNs based anode has offered a greatly improved reversible storage capacity of ∼930 mAh g−1 at 0.1 A g−1 along with an impressive rate capability and cycling life. When S, N-PCNs anode is paired with activated carbon cathode, the 4 V dual-carbon LIC yields an energy density as high as 120.24 Wh kg−1 and 10.2 kW kg−1 of power density with a good cycle stability of 90.6 % after 5000 charge-discharge cycles. This work would open new scopes of exploring metal-organic framework derived heteroatom-doped porous carbons to make metal-ion capacitors more efficient.

Biomass-derived heteroatom-doped carbons: Unlocking the potential of cellulose, hemicellulose, and lignin co-pyrolysis with ammonium polyphosphate for high-performance supercapacitors

Carbon materials were prepared via cellulose, hemicellulose, and lignin co-pyrolysis with ammonium polyphosphate (APP) to scrutinize the influence of these biomass constituents on the materials’ electrochemical performance. During co-pyrolysis, the synergistic interaction between APP and the three components facilitated the doping of heteroatoms including nitrogen, oxygen, and phosphorus. APP with polymerization n > 1000 exhibited the best doping performance. The incorporation of KHCO3 effectively tailored the carbon materials into a hierarchically porous structure predominantly composed of micropores. The cellulose-derived carbon materials outperformed with a remarkable specific capacitance of 398 F/g at 0.5 A/g. Its exceptional electrochemical performance was credited to a notable N content of 3.73 % and a high specific surface area of 1851 m2/g. Our research underscored the potential of cellulose as a readily available and affordable feedstock for crafting carbon materials, suitable for the electrodes in high performance supercapacitors.

Electrochemiluminescence Reveals the Structure-Catalytic Activity Relationship of Heteroatom-Doped Carbon-Based Materials.

Heteroatom doping can change the chemical environment of carbon-based nanomaterials and improve their catalytic performance. Exploring the structure-catalytic activity relationship of heteroatom-doped carbon-based materials is of great significance for studying catalytic mechanisms and designing highly efficient catalysts, but remains a significant challenge. Recently, reactive oxygen species (ROS)-triggered electrochemiluminescence (ECL) has shown great potential for unveiling the mechanism by which heteroatom-doped carbon-based materials catalyze the oxygen reduction reaction (ORR), owing to the high sensitivity of these materials to the properties of the electrode surface. Herein, two kinds of heteroatom-doped porous carbon (denoted as NP-C and N-C) are synthesized and analyzed by monitoring the cathodic ECL of luminol-H2O2 in the low negative-potential region. P, N-doped NP-C exhibitsbetter catalytic ability for activating H2O2 to generate large amounts of •OH and O2 •-, compared with N-C. A sensitive antioxidant-mediated ECL platform is successfully developed for detecting the antioxidant levels in cells, exhibiting considerable potential for evaluating the antioxidant capacity. The relationship between the structure and catalytic mechanism of heteroatom-doped carbon-based materials is successfully explored using ECL, where this method can be universally applied to carbon-based materials.

Rapid preparation of N,P co-doped carbon for advanced oxidative degradation of wastewater

Heteroatom-doped porous carbon materials are highly favored as catalysts for activating persulfates in the oxidative degradation of organic pollutants due to their low metal leaching risk and cost-effectiveness. Nonetheless, the complex process of creating heteroatom-doped carbon materials often results in suboptimal doping effects. This study uses N,P-enriched plants (Eichhornia crassipes after being used for nutrient-rich water remediation) as a raw material to prepare N-P co-doped catalysts in a single step. We thoroughly investigated their performance and mechanisms in dye degradation. The findings demonstrated that the adsorbent, with its rich pore structures, surface chemical functional groups, and graphite defect structures, could completely degrade a 100 mg L−1 MB solution within 20 min. Free radical quenching experiments and EPR analysis confirmed the presence of •OH, SO4•—, O2•— and 1O2, verifying their oxidative contributions. Moreover, it was determined that the non-radical pathway (1O2 oxidation) primarily drives the oxidative degradation in this system. Additionally, tests using a small-scale fixed-bed reactor and interference resistance highlighted the practical application potential of the adsorbent developed in this study. This study not only offers a dual solution for tackling nutrient enrichment and organic pollution in water bodies but also introduces a straightforward method for preparing N, P co-doped catalysts, significantly benefiting environmental protection.

A novel RuP2-infused heteroatom-doped porous carbon for high-durability lithium-sulfur batteries

Nitrogen and phosphorus co-doped three-dimensional porous carbon encapsulated ruthenium diphosphide (PCS900@RuP2-2) is successfully synthesized via a phytic acid-assisted phosphating process. The resulting RuP2 nanoparticles, ranging in size from 10 to 50 nm, are encapsulated within a carbon matrix, providing a stable catalytic structure. Nitrogen adsorption and desorption tests reveal that PCS900@RuP2-2/S possesses a high specific surface area and a rich micro/mesoporous structure. This high porosity facilitates multi-directional ion diffusion and offers ample buffer space to accommodate sulfur volume expansion during cycling. Density functional theory (DFT) calculations confirm that PCS900@RuP2-2/S enables efficient adsorption of soluble polysulfides, thereby minimizing the notorious "shuttle effect." Electrochemical testing demonstrates the remarkable durability of PCS900@RuP2-2/S. After 500 cycles at a 1 C current density, the reversible capacity remains at 511.6 mAh g⁻¹, with an average capacity decay rate of just 0.047 % per cycle. Even under heavy sulfur loading conditions (4.2 mg cm⁻²), the composite maintains a high reversible capacity of 386.6 mAh g⁻¹ after 500 cycles. The combination of high porosity, stable catalytic structure, and efficient redox reaction facilitation contributes to the exceptional performance and longevity of PCS900@RuP2–2/S.

Air‐Pyrolysis Precision Synthesis of Functional Porous Carbon Materials

AbstractCarbon materials play a pivo tal role across various advanced applications, yet their synthesis traditionally necessitates inert atmospheres to avert oxidation at high temperatures, thus inflating production costs and resource utilization. Achieving precision synthesis of functional porous carbon materials via air‐pyrolysis remains a formidable challenge. Herein, a streamlined, one‐step lava‐like carbonization approach is introduced enabling the fabrication of porous carbons boasting tailored morphologies (0‐3D), elevated specific surface areas (540.7–1047.6 m2g⁻¹), heteroatom doping, and commendable carbon yields (20‐39.1%) through direct pyrolysis within an air environment. Leveraging recyclable boric acid as a reaction medium, a lava‐like flowing protective barrier above 170 °C is engendered that spontaneously creates an oxygen‐free‐like milieu devoid of high pressure or intricate procedures. This boron‐containing lava serves dually as a template and chemical activator, facilitating pore formation and catalyzing porous carbon production. Notably, the method accommodates a spectrum of carbon sources, encompassing sugars, proteins, graphene oxide, and their metal mixtures. The resultant morphologically customizable carbons exhibit excellent performance in areas as diverse as microwave absorption and electrocatalysis. This work pioneers a novel pathway for large‐scale precision synthesis of high‐quality carbon materials via air‐pyrolysis under mild conditions.

Highly efficient bifunctional electrocatalyst for rechargeable zinc-air batteries: N, S dual-doped carbon encapsulating sulfur vacancy-rich FeCo/Fe-CoS nanoparticles

In this research, we present a highly efficient bifunctional electrocatalyst, N, S dual-doped carbon framework encapsulating sulfur vacancy-rich FeCo/Fe-CoS nanoparticles (VS-FeCo/Fe-CoS/NSC), synthesized via co-precipitation, sequential pyrolysis and sulfidation process. The prepared electrocatalyst exhibits exceptional performance in oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and rechargeable Zn-air batteries (ZABs). The VS-FeCo/Fe-CoS/NSC-based ZAB demonstrates outstanding bifunctionality, exhibiting high specific capacity of 793 mAh gZn−1 and peak power density of 164.68 mW cm−2. These values surpass those of noble metal-based ZAB, highlighting the superior electrochemical performance of the VS-FeCo/Fe-CoS/NSC catalyst. Such superior activity stems from synergistic effect of abundant heterointerfaces and sulfur vacancies in FeCo/Fe-CoS structure, resulting in enhanced charge transfer efficiency and reaction kinetic performance. Furthermore, the encapsulation of nanoparticles within the heteroatom-doped carbon matrix prevents aggregation and dissolution of active species, ensuring long-term stability during the battery operation. The electrochemical reversibility and stability of VS-FeCo/Fe-CoS/NSC are confirmed through extensive cycling tests, highlighting its potential for practical applications in energy conversion and storage systems.

Polymerizable Ionic Liquid-Derived N, S co-Doped sp3/sp2 Carbon as Electrocatalyst for H2O2 Generation.

The H2O2 generation via the green electrochemical process is of high interest. For the H2O2 electrochemical generation, the oxygen reduction reaction (ORR) is important. Unfortunately, the ORR is kinetically sluggish and catalysts are needed. However, noble metal ORR catalysts are pricy and scarcely applicable in applications. Therefore, non-precious metal catalysts are desired. Heteroatom-doped carbons show promise as metal-free ORR catalysts. The ORR catalytic activity will be enhanced by the carbon's sp2 and/or sp3 engineering. For N, S co-Cdoped and sp2/sp3 modulated carbon, a polymerizable ionic liquid of hydrolyzed vinyl imidazolium was studied. The carbon is studied as a metal-free catalyst for the ORR via the 2e- process. It is possible to get an onset potential of 0.88 V vs. RHE with approximately 50 % selectivity for the H2O2. The current study offers a simple technique for synthesizing heteroatom-doped sp2/sp3 designed carbon as catalysts for the electroreduction of O2 to produce H2O2, and a new way of tunning the sp3/sp2 carbon catalytic activity by modulating the ionic liquid.

Enhanced carbon host with N-reinforced S-sites to catalyze rapid iodine conversion kinetics for Zn-I2 battery

Aqueous zinc-iodine (Zn-I2) battery is a promising energy storage system in the establishment of a low-carbon, clean society, but they are limited by unsatisfied reversible capacity and poor cycle life. Ultimately, this is due to the poor iodine conversion kinetics and the shuttle effect of the intermediate polyiodide. Herein, a N-reinforced S-site carbon host (labeled as NS-YP80F) is designed to resolve these issues. DFT calculation shows that the electrochemical activity of the NS-YP80F with abundant S-site can be further enhanced by introducing N-atom at the original S-site. The synergistic effect of N-reinforced S-site carbon host cannot only enhance the adsorption of polyiodide to avoid the shuttle effect, but also induce the smooth conversion of iodine through enhanced catalytic mechanism. Consequently, the Zn-I2 battery with NS-YP80F@I2 cathode shows high reversible capacity (127 mAh g−1 at 1C) and stable cycling lifespan (15,000 cycles) with a high current density of 50 C. This strategy achieved a breakthrough in the electrochemical activity of the heteroatom doping carbon hosts, and provided a simple and effective solution for optimizing the performance of Zn-I2 battery.