N-doped Carbon Research Articles

Nanosheet-interwoven structures and ion-electron decoupling storage enable Fe1-xS fast ion transport in Li+/Na+/K+ batteries

Fe1-xS, known for its high theoretical capacity, abundant resources, and intrinsic safety, has become a focal point as a universal anode for Li+/Na+/K+ batteries. However, its fast-charging capability is unsatisfactory due to sluggish ion transport rate and low electrical conductivity. Furthermore, its Li+/Na+/K+ storage mechanisms are still unclear. Here, we fabricate a single-crystal Fe1-xS/N-doped carbon composite nanosheet interwoven structure, in which N-doped carbon layers onto surface of Fe1-xS nanosheets ameliorate the electrical conduction and the interwoven nanosheets form open pore channels that favor permeation of electrolytes to boost ion transport. In-situ magnetometry reveals that ion-electron decoupling storage and transport occur in two-phase composites of Fe/Li2S, Fe/Na2S, and Fe/K2S, in which Fe phase stores and transports electrons and sulfide phase stores and transports ions in a space-charge form, resulting in extra ion storage and fast ion transport. Consequently, the nanosheet interwoven structure delivers high capacities (1320.1/652.2/350.6 mAh g−1), outstanding fast-charging performances (679.6/295.4/106.4 mAh g−1 at 20 A g−1), and long cycling life over 5000 cycles as Li+/Na+/K+ battery anodes, respectively

B, N co-doped 3D hierarchical porous carbon entrapping sulfur for high performance of Li-S batteries

The dissolution and diffusion of polysulfide compounds in lithium-sulfur (Li-S) batteries restrict their cyclic stability. The sulfur hosts are the key to achieve good cyclic stability for Li-S batteries. Here, a three-dimensional hierarchical heteroatoms B, N-doped porous carbon (BNC) was prepared as a new sulfur host. The active sulfur can be anchored inside the cathode due to the incorporation of atomic functional groups formed by B and N co-doping, which enhances the adsorption capacity between the cathode and lithium polysulfides. The resulting BNC loaded sulfur (S@BNC) cathode exhibits high specific capacity and electrochemical stability. Specifically, the reversible specific capacity of S@BNC cathode achieved a reversible specific capacity of 1056.8 mAh g−1 at 0.1 C. After 500 cycles, the specific capacity still remains 618.5 mAh g−1 at 0.2 C, which corresponds to a capacity decay rate of 0.0776 %. The results suggest that BNC has great potential as the sulfur host for achieving high performance of Li-S batteries.

Arrayed metal phosphide heterostructure by Fe doping for robust overall water splitting

Transition metal phosphides (TMPs) show promise in water electrolysis due to their electronic structures, which activate hydrogen/oxygen reaction intermediates. However, TMPs face limitations in catalytic efficiency due to insufficient active sites, poor conductivity, and multiple intermediate steps in water electrolysis. Here, we synthesize a highly efficient bifunctional self-supported electrocatalyst, which consists of an N-doped carbon shell anchored on Fe-doped CoP/Co2P arrays on nickel foam (NC@Fe-CoxP/NF) using hydrothermal and phosphorization techniques. Experimental and theoretical results indicate that the modified morphology, with increased active site density and a tunable electronic structure induced by Fe doping in the CoP/Co2P heterostructure, leads to superior water electrolysis performance. The resulting NC@Fe0.1-CoP/Co2P/NF catalyst exhibits overpotentials of 122 mV for the hydrogen evolution reaction (HER) and 270 mV for the oxygen evolution reaction (OER) at 100 mA cm−2. Furthermore, using NC@Fe0.1-CoP/Co2P/NF as both the cathode and anode in an alkaline electrolyzer enables the cell system to achieve 100 mA cm−2 at a voltage of 1.70 V, while maintaining long-term catalytic durability. This work may pave the way for designing self-supported, highly efficient electrocatalysts for practical water electrolysis applications.

Electrochemical sensing for simultaneous determination of dopamine and acetaminophen based on ZIF-8@ZIF-67 derived Co/Mo2C embedded in N-doped carbon hollow nanocages

The exploration of an economical and efficient noble metal-free heterogeneous catalyst is of great significance for the construction of an electrochemical method for the simultaneous detection of Dopamine (DA) and acetaminophen (AC). In this paper, we employed a facile strategy to obtain Co/Mo2C nanoparticles embedded in nitrogen-doped carbon hollow nanocages (Co/Mo2C@N-C HNCs) heterogeneous structure by pyrolyzing ZIF-8@ZIF-67 precursor. The unique hollow structure ensures a fast electron transport channel, N doping regulates the local electronic structure of the catalyst, and the synergistic effect with Mo2C and Co nanoparticles provides more electrocatalytic active sites. The Co/Mo2C@N-C HNCs electrode separates the overlapping voltammetry peaks of DA and AC into two distinct voltammetry peaks (△E=200 mV), thereby selectively determining DA in the presence of AC and vice versa. The transfer coefficient (α) and electron transfer number (n) of DA and AC electrocatalytic oxidation were also studied. Using Co/Mo2C@N-C HNCs as electrode, an electrochemical sensor platform for the simultaneous detection of acetaminophen (AC) and dopamine (DA) was first constructed with linear range of 1–185 μM, and 1–100 μM and low detection limit of 0.35 μM and 0.46 μM for AC and DA, respectively. Satisfactory results have been obtained in the determination of human serum and acetaminophen tablets samples. DFT calculation reveals the molecular mechanisms for DA and AC interacting with the Co/Mo2C@N-C HNCs catalysts. This strategy provides a new idea for the selective determination of several analytes in complex substrates.

Aminotriazine derived N-doped mesoporous carbon with a tunable nitrogen content and their improved oxygen reduction reaction performance.

The electrocatalytic activity of carbon materials is highly dependent on the controlled modulation of their composition and porosity. Herein, mesoporous N-doped carbon with different amounts of nitrogen was synthesized through a unique strategy of using a high nitrogen containing CN precursor, 3-amino 1,2,4 triazine (3-ATZ) which is generally used for the preparation of carbon nitrides, integrated with the combination of a templating method and high temperature treatment. The nitrogen content and the graphitisation of the prepared materials were finely tuned with the simple adjustment of the carbonisation temperature (800-1100 °C). The optimised sample as an electrocatalyst for oxygen reduction reaction (ORR) exhibited an onset potential of 0.87 V vs. RHE with a current density of 5.1 mA cm-2 and a high kinetic current density (Jk) of 33.1 mA cm-2 at 0.55 V vs. RHE. The characterisation results of the prepared materials indicated that pyridinic and graphitic nitrogen in the carbon framework promoted ORR activity with improved four-electron selectivity and excellent methanol tolerance and stability. DFT calculations demonstrated that the structural and planar defects in the N-doped carbon regulated the surface electronic properties of the electrocatalyst, leading to a reduction in the energy barrier for the ORR activity. This strategy has the potential to unlock a platform for designing a series of catalysts for electrochemical applications.

Promoting Electrocatalytic Reduction of CO2 and Nitrate to Urea on N-Doped Porous Hollow Carbon Spheres.

The electrocatalytic coreduction of CO2 and nitrate is a green method for urea synthesis, mitigating CO2 emission and nitrate contamination. However, its slow kinetics and high energy barrier result in a poor urea production performance. Herein, we reported N-doped porous hollow carbon spheres (N-PHCS) for promoting CO2 and nitrate conversion to urea via nanoconfinement and N-doping from both reaction kinetics and thermodynamics. A high urea yield of 12.0 mmol h-1 gcat-1 with Faradaic efficiency of 19.1% was achieved on N-PHCS at -1.0 V (vs Ag/AgCl), which was comparable to or even higher than those of metal-based electrocatalysts reported. The experimental and theoretical calculation results revealed that carbon spheres with an appropriate interior void and pore size were favorable for confining reactants and intermediates to accelerate urea production, while N-doping can reduce the energy barrier for urea synthesis. By regulating the microstructure and N doping of N-PHCS, it showed a superior performance for urea electrosynthesis. The energy favorable pathway for urea synthesis was through the C-N coupling reaction of *NO and *CO, and pyridinic N can reduce the reaction energy barrier.

Enhanced stability in Co0.8Ni0.2/NDMCS catalysts: Carbon nitride encapsulation for robust hydrogen generation

Catalytic hydrolysis of NaBH4 is a promising method for "on-demand" hydrogen generation, with cobalt catalysts playing a key role due to their high hydrogen generation rates. However, rapid cobalt dissolution and poor recycling hinder stable hydrogen production. This study presents a dual-mode stabilization technique using carbon nitride encapsulation to address these challenges. Co0.8Ni0.2 alloy nanoparticles (NPs) are confined within N-doped mesoporous carbon spheres (NDMCS) and encapsulated with a carbon nitride shell (∼ 5 nm thick). XPS results reveal strong non-classical metal-support interaction, increasing activation energy from 38.82 to 44.6 kJ mol−1, which controls cobalt's reactivity, leading to excellent recycling efficiency (90 % retention of initial rate, no change in particle size) in high-concentration reactants (2 %NaBH4 + 2 %NaOH). The retention rate drops to 26.8 % without this stabilization due to rapid metal dissolution. This stability of Co0.8Ni0.2 alloy in alkaline conditions has significant practical implications for hydrogen generation and other electrochemical applications.

Constructing stress-release layer on Si nanoparticles for high-performance lithium storage

Tailing structures of silicon anode to alleviate the mechanical stress has an important significance in the development of lithium-ion batteries (LIBs). Herein, the stress-released layer of N-doped cubic carbon on the surface of Si nanoparticles (Si@NCC) is explored to stabilize the electrode. Endowed with the unique superiority, the Si@NCC electrode delivers an impressive lithium storage performance with high specific capacity of 630 mAh/g at 0.1 A/g, excellent cycling stability (72.0 % capacity retention after 100 cycles at 0.1 A/g) and good rate capability (375 mAh/g at 2 A/g). It has been demonstrated that the N-doped cubic carbon shell with high conductivity can effectively limit the expansion and agglomeration of Si nanoparticles. Besides, the COMSOL simulations of the stress distributions in materials confirm that the N-doped cubic carbon layer could remarkably decrease the stress originated from the volume expansion of Si nanoparticles during the lithiation. Therefore, this work provides ideas for the mechanical effect of Si-based anodes for lithium storage and sheds lights on the designing advanced materials toward high-performance energy storage devices.

Enhanced degradation of tetracycline in water by LaFeO3 supported on N-doped porous carbon derived from waste medical masks through activation of peroxymonosulfate

A novel nitrogen-doped porous carbon loaded with LaFeO3 (NC@LaFeO3) was prepared using polypyrrole (PPy)-functionalized waste medical masks as the carbon precursor and then applied as a highly efficient catalyst to construct peroxymonosulfate (PMS)-induced advanced oxidation process for removal of tetracycline (TC) in water. The results showed that N-doped porous carbon derived from PPy-functionalized waste medical masks could be used as a good carrier for LaFeO3. The as-prepared NC@LaFeO3 exhibited synergistic effects and showed excellent catalytic performances, in which 99.9 % of TC could be removed within 20 min at catalyst dosage of 0.4 g/L, PMS concentration of 5.0 mmol/L and initial TC concentration of 10 mg/L at natural pH. The incorporation of LaFeO3 into nitrogen-doped carbon not only demonstrated broad pH applicability (4.0–10.0) and good resistance to inorganic anions, but also improved the cycling stability and reusability with removal efficiency of TC maintaining at 87.6 % after 5 cycles. Superoxide radical (O2•−) was the leading reactive oxygen species, and both free radical and non-free radical pathways were all involved in TC degradation. Combined with XPS spectra, free radical quenching experiments, EPR analysis and the identification of degradation intermediates, the possible mechanisms and pathways of TC degradation by NC@LaFeO3/PMS system were proposed. This study presented a viable approach to construct high-efficiency carbon-based catalyst from waste medical masks for water pollution control and remediation, which could accomplish the dual purposes of turning waste into treasure and using waste to treat waste.

Synergistic effect of nanocrystalline NiCo2S4 and NiCo alloy embedded in N-doped carbon fibers towards high-performance electrocatalysts for oxygen evolution reaction

Developing oxygen evolution reaction (OER) electrocatalysts with high efficiency, low cost and good stability for water splitting is significant to relieve the energy crisis and environmental pollution. Herein, NiCo alloy (NC) nanoparticles (NPs) embedded N-doped carbon fibers (NCF) were prepared by electrospinning and carbonization. The surfaces of the NC@NCF were anchored with nanocrystalline NiCo2S4 (NCS) in a following solvothermal process to form NCS-NC@NCF composite. Synergistic effect of the alloy (NC) and the semiconductor (NCS) was successfully stimulated, i.e., rapid charge separation and transfer was achieved during the OER process. In addition, the carbon fibers substrate is beneficial for good dispersion of the NC and NCS NPs as well as the conductivity improvement of the as-prepared NCS-NC@NCF catalyst. The prepared NCS-NC@NCF catalyst electrode owns good OER performances of a low overpotential of 291 mV, 342 mV and 376 mV to respectively deliver current densities of 10 mA cm−2, 50 mA cm−2 and 100 mA cm−2, which are respectively 19 mV, 82 mV and 116 mV lower than those of the RuO2 electrode (310 mV, 424 mV and 492 mV), indicating the great potential of the catalyst in water splitting. Moreover, good durability of current density retention of 90.7 % is observed after 60 h of continuous OER polarization for the catalyst. Additionally, a two-electrode system composed of commercial Pt/C and the NCS-NC@NCF electrodes only needs a driven voltage of 1.51 V to afford 10 mA cm−2 for water splitting, which is superior to that (1.69 V) of the Pt/C||RuO2 system.

Boosting oxygen reduction performance by copper-iron co-doped on ZIF-derived N-doped carbon nanotubes

Developing high-efficiency non-noble metal catalysts for the oxygen reduction reaction (ORR) is paramount for sustainable energy conversion. In this study, we proposed a Cu, Fe co-doped zeolite imidazole framework (ZIF)-derived nitrogen-doped carbon nanotubes catalyst (Cu–Fe@CNTs/NC) obtained by hydrothermal method and pyrolysis. The electrochemical results showed that Cu–Fe@CNTs/NC exhibited favorable oxygen reduction performance and good stability under alkaline electrolyte. The incorporation of Cu and Fe bimetallic dopants promoted the carbon nanotubes growth on ZIF nanosheets, and the collaborative action of Cu and Fe enhanced its ORR catalytic activity. These findings provide an innovative way to prepare high active non-platinum ORR catalysts.

Selective electro-capacitive deionization of Yb(III) by nanospherical N-doped carbon supported nickel‑iron bimetallic oxide, nitride and phosphide

The separation of rare earth elements from the mining waste water is highly important but still facing challenge. In this study, three different porous composite electrode materials were well-designed by decorating the nickel‑iron bimetallic oxide, nitride or phosphide onto nitrogen-doped carbon nanosphere, respectively (termed as NiFeO@NC, NiFeN@NC and NiFeP@NC), and utilized in capacitive deionization device for electrosorption of Yb(III) from water under the low-voltage electric field. The characterization and electrochemical results indicated that the incorporation of N or P atom lead to the reduced specific surface area and the enhanced electrochemical properties (i.e., larger specific capacitance, lower charge transfer resistance). In addition, NiFeN@NC and NiFeP@NC exhibited the excellent electrosorption capacities of Yb(III) with 105.24 mg·g−1 and 90.31 mg·g−1, respectively, under conditions of a flow rate of 20 mL·min−1, a voltage of 1.2 V, and pH of 5.0, which was extremely higher than NiFeO@NC (i.e., 50.7 mg·g−1). Moreover, all these three materials also demonstrated the remarkable electrosorption selectivity of Yb(III) from the mixed solution, and the robust durability with over 90 % of initial capacities after ten consecutive electrosorption-desorption cycles. Furthermore, the XPS characterizations and electrosorption results revealed that the electrosorption mechanism mainly depended on the synergistic effects of intrinsic Faraday redox reaction, electric double layer capacitance and active binding sites. Therefore, this work provided a feasible strategy for the separation of rare earth elements from aqueous solution, and the prospective applications related to the recovery of rare earth elements from mining wastes or spent permanent magnets in future life.

Surface Engineering of N‐Doped Carbon Derived from Polyaniline for Primary Zinc‐Air Batteries

AbstractZinc‐air batteries (ZABs) with metal‐free cathodes are considered environmentally friendly and cost‐effective. However, more active and durable catalysts are required for this purpose. Herein, polyaniline (PANI)‐derived carbon materials were obtained to boost the oxygen reduction reaction (ORR) and, consequently, the performance of a primary ZAB. The developed porous N‐doped carbon (NDC) materials were engineered by varying the polymerization time and calcination temperature (500–900 °C). SEM micrographs and BET surface areas showed that the polymerization of aniline under cold conditions (5 °C) at 6, 8, or 24 h did not have a significant effect on the morphology or surface area. The fibrous structure of PANI was engineered by temperature, resulting in a progressive increase in the surface area until a three‐dimensional porous structure was achieved at 900 °C with the highest area of 601.9 m2 g−1. The surface doping of nitrogen species shifted from PANI‐rich N species to enriched graphitic N from 12.69 % (500 °C) to 24.26 % at 900 °C. The NDC 900 °C presented a voltage of 1.4 V and power density of 56 mW cm−2 (only 7 mW cm−2 lower than that of Pt/C). The results demonstrate that this material is an excellent candidate for high‐performance primary ZABs.

Vertically-stacked W/W2C heterojunctions with high electrocatalytic capability for the hydrogen evolution reaction in a wide pH range

The hydrogen evolution reaction (HER) in water splitting is among the foremost methods to produce clean and green hydrogen from renewable sources. The practical use of the HER technology is however hindered by the high price and/or the relatively low efficiency of the currently used catalysts. Herein, we report a heterostructured W/W2C electrocatalyst featuring vertically stacked interfaces and embedded in N-doped porous graphitic carbon (denoted as W/W2C@N-PGC) as a high-performance electrocatalyst for the HER in a wide pH range. The catalyst synthesis, accomplished through a straightforward one-pot method, is both facile and highly efficient, involving freeze-drying a suspension of the starting materials followed by pyrolyzing the obtained dry gel. Density functional theory calculations revealed the crucial role of the W/W2C heterojunction in promoting the two key steps of the HER, viz. HOH bond scission and H2 emission. Electrochemical data confirmed the excellent electrocatalytic capability of W/W2C@N-PGC toward the HER process in a wide pH range including alkaline, acidic, and neutral electrolytes. In 1.0 M KOH, we measured a low overpotential of 102 mV to drive a current density of 10 mA cm−2; a long-term stability (up to 24 h) was also realized. The data presented in this work highlight the importance of electrocatalysts with heterojunctions for the HER and the methodology presented in this work may be extended to other contemporary energy-related technologies such as CO2 reduction, oxygen evolution, and oxygen reduction reactions.

Interfacial Sb[sbnd]O[sbnd]C bond and structural confinement synergistically boosting the reaction kinetics and reversibility of Sb2Se3/NC nanorods anode for sodium storage

Antimony selenide (Sb2Se3) has been considered as a prospective material for sodium-ion batteries (SIBs) because of its large theoretical capacity. Whereas, grievous volume expansion caused by the conversion-alloying reaction leads to fast capacity decay and inferior cycle stability. Herein, the confined Sb2Se3 nanorods in nitrogen-doped carbon (Sb2Se3/NC) with interfacial chemical bond is designed to further enhance sodium storage properties of Sb2Se3. The robust enhancing effect of interfacial SbOC bonds can significantly promote electron transfer, Na+ ions diffusion kinetics and alloying reaction reversibility, combining the synergistic effect of the unique confinement structure of N-doped carbon shells can efficiently alleviate the volume change to ensure the structural integrity. Moreover, in-situ X-ray diffraction reveals intercalation/de-intercalation, conversion/reversed conversion reaction and alloying/de-alloying reaction mechanisms, and the kinetics analysis demonstrates the diffusion-controlled to contribute high capacity. As a result, Sb2Se3/NC anode delivers a high reversible capacity of 612.6 mAh/g at 0.1 A/g with a retentive specific capacity of 471.4 mAh/g after 1000 cycles, and long-cycle durability of over 2000 cycle with the reversible capacities of 371.1 and 297.3 mAh/g at 1 and 2 A/g are achieved, respectively, and an good rate capability. This distinctive interfacial chemical bonds and confinement effect design shows potential applications in the improved conversion/alloying-type materials for SIBs.

N-doped carbon dots-modulated interfacial charge transfer and surface structure in FeNbO4 photocatalysts for enhanced CO2 conversion selectivity to CH4

The photocatalytic carbon dioxide reduction reaction (CO2RR) is an innovative and reliable technology to address the issues of energy shortage and climate change simultaneously. However, issues such as insufficient light absorption, rapid electron-hole recombination and low surface activity during CO2RR severely limit the catalysts’ efficiency for photocatalysis. In this study, we present nanohybrid N-CDs/FeNbO4 catalysts to overcome these challenges and achieve high-efficient photocatalytic conversion of CO2 to CH4. The enhancement process starts with the introduction of modified N-CDs, which have a broad light absorption capability. These N-CDs also help to modulate the interfacial charge transfer kinetics, leading to improved charge separation and transfer. This, in turn, enhances the multielectron transfer conversion selectivity of CO2 to CH4. Meanwhile, CO2 adsorption on the photocatalysts is increased due to the creation of oxygen vacancies and lattice stresses resulting from the introduction of N-CDs. This work presents a new approach for improving the photocatalytic performance by adjusting surface structure and interfacial behaviors.

Dual-functional paper-like evaporator for boosting interfacial evaporation synchronized with organic pollutant degradation

Solar-driven interfacial evaporation is a sustainable method to produce freshwater, but volatile organic compounds (VOCs) inevitable accumulate in the condensed water, causing secondary pollution. Herein, paper-like photothermal evaporators were constructed by fixing zeolitic diazoate frameworks-8 derived N-doped carbon with different morphologies on the interwoven cellulose nanofibrils (CNFs) membranes for simultaneous steam generation and organic pollutant degradation. The results showed that the evaporator incorporated porous N-doped carbon with rhombic dodecahedron (NC-RD) into CNFs membranes not only increases the roughness to achieve broad spectrum solar absorption, but also capable of ensuring continuous evaporation of water, and maintaining a sufficient water supply. The NC-RD/CNFs membranes exhibit the high evaporation rate of 1.46 kg·m−2·h−1 under one sun. Meanwhile, N-doped carbon enable photothermal-synergistic peroxymonosulfate (PMS) activation to promote the generation of abundant 1O2 and O2∙– for degradation of methylene blue, tetracycline and phenol. Furthermore, the solar-vapor conversion efficiency and the evaporation rate are stable in a simulated seawater environment with 15 wt% NaCl solution. Importantly, an outdoor NC-RD/CNFs-based device was constructed, which realizes a high evaporation rate of 0.659 kg∙m−2∙h−1 under natural light irradiation for 10 h. The present study highlights that the NC-RD/CNFs membranes successfully coupled interfacial evaporation with PMS based-advanced oxidation processes to provide a subtlety strategy to solve the problem of VOCs accumulation in the evaporation process.

Selective electrosynthesis of ammonia via nitric oxide electroreduction catalyzed by copper nanowires infused in nitrogen-doped carbon nanorods

The electrochemical nitric oxide reduction reaction (eNORR) is meticulously investigated as an alternative to the energy intensive Haber-Bosch process to produce Ammonia (NH3). However, the eNORR is hindered by NH3 selectivity due to side reactions and mass-transfer limitations. In this work, we rationally designed copper nanowires (Cu NWs) infused in the lotus-root-like multi-nano-channels of the porous N-doped carbon nanorods (Cu-mNCNR) for a high selective eNORR to synthesize NH3 at ambient conditions. The optimized catalyst, Cu-mNCNR2, has achieved the highest NH3 Faradaic efficiency of 79% with NH3 yield rate of 34.5 μmol cm–2 h–1 at −0.4 VRHE. Moreover, the Cu-mNCNR2 has demonstrated a vigorous performance in the 24 h continuous NO electrolysis to produce NH3. Additionally, a prototype device, the Zn-NO battery, was demonstrated. This study shows that the rational design of a catalyst considering mass-transfer limitations is crucial to achieving high selective NH3 electrosynthesis in eNORR.

Tuning the interfacial reaction environment via pH-dependent and induced ions to understand C–N bonds coupling performance in NO3− integrated CO2 reduction to carbon and nitrogen compounds over dual Cu-based N-doped carbon catalyst

Dual atomic catalysts (DAC), particularly copper (Cu2)-based nitrogen (N) doped graphene, show great potential to effectively convert CO2 and nitrate (NO3−) into important industrial chemicals such as ethylene, glycol, acetamide, and urea through an efficient catalytical process that involves C–C and C–N coupling. However, the origin of the coupling activity remained unclear, which substantially hinders the rational design of Cu-based catalysts for the N-integrated CO2 reduction reaction (CO2RR). To address this challenge, this work performed advanced density functional theory calculations incorporating explicit solvation based on a Cu2-based N-doped carbon (Cu2N6C10) catalyst for CO2RR. These calculations are aimed to gain insight into the reaction mechanisms for the synthesis of ethylene, acetamide, and urea via coupling in the interfacial reaction micro-environment. Due to the sluggishness of CO2, the formation of a solvation electric layer by anions (F−, Cl−, Br−, and I−) and cations (Na+, Mg2+, K+, and Ca2+) leads to electron transfer towards the Cu surface. This process significantly accelerates the reduction of CO2. These results reveal that *CO intermediates play a pivotal role in N-integrated CO2RR. Remarkably, the Cu2-based N-doped carbon catalyst examined in this study has demonstrated the most potential for C–N coupling to date. Our findings reveal that through the process of a condensation reaction between *CO and NH2OH for urea synthesis, *NO3− is reduced to *NH3, and *CO2 to *CCO at dual Cu atom sites. This dual-site reduction facilitates the synthesis of acetamide through a nucleophilic reaction between NH3 and the ketene intermediate. Furthermore, we found that the I− and Mg2+ ions, influenced by pH, were highly effective for acetamide and ammonia synthesis, except when F− and Ca2+ were present. Furthermore, the mechanisms of C–N bond formation were investigated via ab-initio molecular dynamics simulations, and we found that adjusting the micro-environment can change the dominant side reaction, shifting from hydrogen production in acidic conditions to water reduction in alkaline ones. This study introduces a novel approach using ion-H2O cages to significantly enhance the efficiency of C–N coupling reactions.

The Facile Production of p-Chloroaniline Facilitated by an Efficient and Chemoselective Metal-Free N/S Co-Doped Carbon Catalyst.

The catalytic hydrogenation of the toxic and harmful p-chloronitrobenzene to produce the value-added p-chloroaniline is an essential reaction for the sustainable chemical industry. Nevertheless, ensuring satisfactory control of its chemoselectivity is a great challenge. In this work, a N/S co-doped metal-free carbon catalyst has been fabricated by using cysteine as a source of C, N, and S. The presence of calcium citrate (porogen agent) in the mixture subjected to pyrolysis provided the carbon with porosity, which permitted us to overcome the issues associated with the loss of heteroatoms during an otherwise necessary activation thermal treatment. Full characterization was carried out and the catalytic performance of the metal-free carbon material was tested in the hydrogenation reaction of p-chloronitrobenzene to selectively produce p-chloroaniline. Full selectivity was obtained but conversion was highly dependent on the introduction of S due to the synergetic effect of S and N heteroatoms. The N/S co-doped carbon (CYSCIT) exhibits a mesoporous architecture which favors mass transfer and a higher doping level, with more exposed N and S doping atoms which act as catalytic sites for the hydrogenation of p-chloronitrobenzene, resulting in enhanced catalytic performance when compared to the N-doped carbon obtained from melamine and calcium citrate (MELCIT) used as a reference.