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In this work, N-doped and oxygen vacancy-rich NiCo2O4/NiO/Co3O4 composites are synthesized by the direct calcination method. Noticeably, by changing the additive concentrations of urea dissolved in DMF (N–N dimethylformamide), the electromagnetic wave (EMW) absorption abilities of NiCo2O4/NiO/Co3O4 composite effectively. A maximum reflection loss (RLmax) value at 12.94 GHz for a 2.8 mm thick sheet is −29.76 dB, while its effective absorption bandwidth (RL < −10 dB) reaches 4.21 GHz. In-depth research of possible mechanisms of EMW absorption enhancement. Owing to its simple preparation method and superb EMW absorption properties, the NiCo2O4/NiO/Co3O4 composites have a chance to be suitable candidates for high-property EMW absorbers. [ABSTRACT FROM AUTHOR]

Humic acid (HA) is the main precursor of carcinogenic compounds such as trichloromethane, which form during the disinfection of drinking water. Therefore, removing HA from water sources is crucial for producing safe drinking water. This study introduces a novel approach using dilute nitric acid as a nitrogen source to dope pristine Ti3AlC2 (TAC) to varying degrees, enhancing the material's photocatalytic degradation performance for HA. Characterisations through X‐ray diffraction, Fourier transform infrared, scanning electron microscopy, UV–vis and X‐ray photoelectron spectroscopy revealed that the surface morphology of the modified catalyst changed from an original blocky lamellar structure to a rod‐like cluster structure, which is advantageous for light trapping. In addition, the incorporation of nitrogen reduced the band gap of the material from 1.25 to 1.15 eV, considerably enhancing its overall light responsiveness and thereby improving its photocatalytic performance. The results demonstrated that the photocatalytic degradation efficiency of HA by TAC under optimal conditions reached 93.8 %, which is 4.3 times higher than the 21.8 % efficiency achieved using the undoped TAC material. The enhanced photocatalytic activity is attributed to N doping, which not only reduces the TiO2 band gap at the TAC surface but also improves the electrochemical behaviour of TAC. This results in enhanced light response and more efficient separation of photogenerated electron–hole pairs. The mechanism for CTAC–Nx photocatalytic degradation of HA was investigated using trapping agent experiments, revealing that the primary active substance responsible for the degradation is O2−. [ABSTRACT FROM AUTHOR]

Being an alien species, Spartina alterniflora has occupied the living space of native animals and plants, causing irreversible damage to the environment. Converting Spartina alterniflora into carbon or its derivatives offers a valuable solution to manage both invasive biomass and an energy shortage. Herein, through a simple activation process, we successfully prepared Spartina alterniflora-derived carbon (SAC) and its N-doped derivative SANC, and used them as metal-free catalysts for an oxygen reduction reaction (ORR). SAC exhibits good electrochemical performance and holds significant potential in catalysis. After N-doping by melamine as a nitrogen source, electronegativity is redistributed in SANC, leading to enhanced performance (a half-wave potential of 0.716 V vs. RHE, and a four-electron transfer pathway with a H2O2 yield of only 2.05%). This work presents a straightforward and cost-effective approach to the usage of obsolete invasive biomass and shows great potential in energy generation. [ABSTRACT FROM AUTHOR]

To meet the demands for high-performance and cost-effective electromagnetic wave absorbers in practical applications, CoNi alloy/N-doped hollow carbon foam (CoNi/NCF) was synthesized using melamine foam as a precursor through a hydrothermal reaction. By introduction of appropriate CoNi alloys to form uniform magnetic metal nanoparticles on the surface of NCF, the electromagnetic wave absorption performance of NCF can be adjusted. These metal nanoparticles formed rich heterogeneous interfaces with the NCF, enhancing the interface polarization loss of the composite material to electromagnetic waves. The CoNi alloy increased the conductivity of composite materials, which was conducive to the formation of a three-dimensional conductive network and promoted the conduction loss of electromagnetic waves. As a magnetic metal, the CoNi alloy also brought magnetic losses to composite materials, increasing the ways to consume electromagnetic waves. Additionally, the doping of N atoms increased the dipole polarization loss of the NCF. The minimum reflection loss (RLmin) of CoNi/NCF reached −47.35 dB, and the maximum effective absorption bandwidth (EAB) reached 5.6 GHz (2.4 mm). CoNi/NCF effectively reduced the radar cross-section (RCS) signal on the surface of the electric conductor layer. This study provides a feasible strategy for developing magnetic composite carbon materials with an efficient electromagnetic wave absorption performance. [ABSTRACT FROM AUTHOR]

In this study, a lignin-based aerogel (LA) was prepared through acid precipitation of BPBL, followed by sol–gel method and freeze-drying. Additionally, a one-step activation-carbonization method was used to acquire nitrogen-doped lignin-based activated carbon aerogel (NLACA). The adsorption and catalytic degradation performance for malachite green (MG) were examined. The specific surface area of NLACA after N-doping was 2644.5 m2/g. The adsorption capacity for MG was increased to 3433 mg/g with the presence of nitrogenous functional groups on surface of NLACA compared without N-doping. Meanwhile, non-radical singlet oxygen is the primary active substance and degradation efficiency arrives at 91.8% after the catalytic degradation within 20 min and it has good stability and reuse. Three possible degradation pathways during degradation were analyzed by LC–MS technique. The adsorption isotherm and kinetic data demonstrated conformity with both the Langmuir model and the pseudo-second-order kinetic model. The primary mechanisms of the adsorption for MG dyes on NLACA include hydrogen bonding, π-π interactions, attraction of electrostatic and pore filling. Hence, NLACA derived from BPBL acts as a cost-effective and high-performance adsorbent and catalyst for removal of MG in dye wastewater. This concept introduces an innovative approach of "treatment of waste with waste" for developing a low-consumption, high-efficiency dye wastewater treatment and provides significant reference to treatment dye wastewater. [ABSTRACT FROM AUTHOR]

Abstract Oxycodone, often used as an analgesic, is a potent opioid. While its effectiveness has been proven in the control of moderate to acute pain, excessive use of oxycodone imposes heart failure, heart palpitations, reduction of red blood cells, bone pain, and even death. Therefore, monitoring the oxycodone concentration in blood is vital for emergency care. For this purpose, a novel electrochemical sensor was designed based on a glassy carbon electrode modified with mesoporous g-C3N4 (M-C3N4), carbon nano-onions doped with nitrogen (N-CNO), and gold nanoparticles. At first, the SEM and XRD techniques were employed to characterize prepared M-C3N4 and N-CNO samples. The electro-oxidation behavior of the oxycodone was evaluated by cyclic and differential pulse voltammetric methods. Based on the influence of the potential scanning rate and solution pH on the voltammetric response of oxycodone oxidation, a redox mechanism was proposed. A 16 nM detection limit was acquired for the oxycodone analysis with a linear response in the 0.05–150 µM range. This sensor showed a remarkable ability for oxycodone detection in plasma samples. The long-term stability, superior selectivity, and reproducibility of this sensor prove its ability to measure oxycodone accurately and precisely in authentic spices.

Oxycodone, often used as an analgesic, is a potent opioid. While its effectiveness has been proven in the control of moderate to acute pain, excessive use of oxycodone imposes heart failure, heart palpitations, reduction of red blood cells, bone pain, and even death. Therefore, monitoring the oxycodone concentration in blood is vital for emergency care. For this purpose, a novel electrochemical sensor was designed based on a glassy carbon electrode modified with mesoporous g-C3N4 (M-C3N4), carbon nano-onions doped with nitrogen (N-CNO), and gold nanoparticles. At first, the SEM and XRD techniques were employed to characterize prepared M-C3N4 and N-CNO samples. The electro-oxidation behavior of the oxycodone was evaluated by cyclic and differential pulse voltammetric methods. Based on the influence of the potential scanning rate and solution pH on the voltammetric response of oxycodone oxidation, a redox mechanism was proposed. A 16 nM detection limit was acquired for the oxycodone analysis with a linear response in the 0.05–150 µM range. This sensor showed a remarkable ability for oxycodone detection in plasma samples. The long-term stability, superior selectivity, and reproducibility of this sensor prove its ability to measure oxycodone accurately and precisely in authentic spices. [ABSTRACT FROM AUTHOR]

Activated carbon materials derived from biomass for supercapacitors have received great attention due to their natural abundance and low cost. The agricultural waste walnut green peel can be a promising activated carbon electrode material and resource utilization of it would effectively alleviate the environmental pollution problem. Here we reported the N-doped activated carbon materials (N/ACs) from walnut green peel using melamine as the nitrogen source. N/ACs showed obvious pore structure, high specific surface area, low resistance, and fast charge transfer rate. Thereinto, the optimized N/AC-2 showed the most excellent and better capacitive performance, with the specific capacitance of 304.5 F g−1 at 0.5 A g−1. N/AC-2 exhibited high energy density (40.05 W h kg−1) and power density (22.5 kW kg−1) as the supercapacitor electrode. In addition, the capacitance retention rate of N/AC-2 remained 95.2% after 3000 cycles at 10 A g−1. Our work demonstrated that the prepared N/ACs would be more promising electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

In this paper, Fe3O4@SiO2@TiO2 and N-doped Fe3O4@SiO2@N-TiO2 photocatalysts with magnetic core-shell structures were prepared using a multi-step synthesis method. The materials were analyzed using various techniques, such as X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), selected-area electron diffraction patterns (SAED), and X-ray photoelectron spectroscopy (XPS). The results indicated that the prepared samples had an anatase structure, and N was successfully doped. Fe3O4@SiO2@TiO2 and Fe3O4@SiO2@N-TiO2 with different amounts of nitrogen doping were used for the study of photocatalytic degradation of methyl orange (MO) in pure MO solution, and in MO and Na2SO4 (MO-Na2SO4) mixed solution, respectively. The average photocatalytic degradation rate of MO in pure MO solution with three different batches each of Fe3O4@SiO2@TiO2 and Fe3O4@SiO2@N-TiO2 (3 mL of NH4OH used for doping) under high-pressure mercury lamp irradiation reached 85.25% ± 2.23% and 95.53% ± 0.53%, respectively. The average photocatalytic degradation rate of MO in the MO-Na2SO4 mixed solution with three different batches each of Fe3O4@SiO2@TiO2 and Fe3O4@SiO2@N-TiO2 (3 mL of NH4OH used for doping) under the same irradiation condition reached 90.46% ± 3.33% and 97.79% ± 2.09%, respectively. The results showed that Na2SO4 can promote photocatalytic degradation of MO. The experiment of recycling photocatalysts showed that there was still a good degradation effect after five cycles. Finally, the first-order kinetic model and the photocatalytic degradation mechanism were investigated. [ABSTRACT FROM AUTHOR]

Achieving precise control over the site-selective production of deuterium-labeled alkenes under mild conditions is highly appealing. However, it is crucial to determine how to use a green chemical process and an economical deuterium source to achieve this goal. In this paper, Pd nanoparticles supported on N-doped porous carbon (Pd0.05-NC) on the cathode for the electrocatalytic semideuteration reaction of alkynes with D2O. The reaction exhibits a high selectivity of 96% and a Faradaic efficiency (FE) of 74.9% under low voltage conditions. Mechanistic studies highlight the importance of adsorption of alkynes and the activation of D2O on the Pd0.05-NC cathode surface to achieve highly selective and efficient synthesis. The capture of key deuterium and carbon radicals confirms the existence of the reactive D species addition pathway and cross-coupling of free radicals. The gram-scale synthesis of deuterated alkenes in a continuous-flow electrolyzer and the wide range of substrates highlight their promising applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new strategy for using waste cork. • PC4-800 exhibits excellent pore structure and abundant N-containing groups. • PC4-800 has ultra-high toluene capture of 867.03 mg/g. • Pores with sizes of 1.71–2.28 nm are most effective for adsorption. • N-6 had the strongest affinity for toluene through Gaussian imitating. Converting waste resources into porous carbon for pollutants capture is an effective strategy to achieve the environmental goal of "treating waste with waste". Cork is an ideal precursor of porous carbons due to its ordered honeycomb-like cell structure and layered composition distribution. Herein, N-doped porous carbons (PCs) were prepared via two steps of urea-assisted hydrothermal carbonization and chemical activation to mitigate volatile organic compounds (VOCs) pollution. Results indicated that the obtained PC4-800 exhibited remarkable features for adsorption including high total pore volume (0.97 cm3/g) and specific surface area (1864.89 m2/g), as well as abundant N-containing functional groups. The excellent pore structure was primarily owing to the corrosion of the carbon matrix by the gas produced from the reaction of K 2 CO 3 and N-containing functional groups. The adsorption results showed that the PC4-800 have an outstanding toluene adsorption capacity (867.03 mg/g) that outperforming majority of adsorbents previously reported. There are substantial pores in N-doped PCs with a pore width of 1.71–2.28 nm, which is 3 to 4 times the molecular dynamic diameter of toluene, and plays a crucial role in the absorption process. Moreover, the promotional influence of N-functional groups on the toluene adsorption process was verified through DFT calculation by Gaussian imitating, where N-6 generated π-electron enrichment sites on the surface of N-doped PCs, facilitating π-π dispersion with the benzene ring in toluene. This study provides a new strategy to convert waste cork into high-performance adsorbents for VOCs removal. [ABSTRACT FROM AUTHOR]

Derivatives of 2,4-dimethyldihydrocyclopentadiene were prepared, characterized by NMR spectroscopy, which was applied to 1-decene oligomerization. A two-step activation method in which both triisobutylaluminium (TIBA) and methyl aluminoxane (MAO) were co-used in sequence particularly been developed for N-doped ligand catalyst. N-doped catalyst had a very high polymerization conversion at 60–110 °C by varying the reaction temperature at 20 eq. of TIBA and 100 eq. of MAO, reaching 89.95% at 80 °C. In addition, oligomers with different viscosity grades could be obtained by adjusting the temperature. At optimized reaction conditions 75 °C, 10 eq. of TIBA and 50 eq. of MAO activation, the single pass conversion of 91.33% was achieved. The obtained oligomers had a high viscosity index above 170 at KV100 = 6. In addition, the two-step activation method was used to compare with the conventional one-step activation method on catalysts with three different ligands of zirconium chloride. A high catalytic productivity was achieved by the two-step activation process. Depending on the nature of the ligands used, β-hydride elimination, 2,1 insertion and 1,2 rearrangement were detected as main chain release mechanisms. Meanwhile, the pathways of oligomer formation were also summarized. In brief, N-doped complex is promising catalysts for the production of high quality lubricant base oils due to their high catalytic activity and high thermal stability. [ABSTRACT FROM AUTHOR]

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Context: To explore the impact of OGs (OGs) on formaldehyde (HCHO) adsorption by modified activated carbon, this paper studied the influence of OGs on HCHO adsorption characteristics, varying the groups including ester, carboxyl, and hydroxyl. Employing density functional theory (DFT), the effects of various OGs on the structure of N-doped activated carbon through GGA-PBE exchange-correlation functionals by Materials Studio combined with Gaussian software. The types of weak interactions during the adsorption process were calculated by RDG, elucidating the mechanism through which the three OGs affect HCHO adsorption on N-doped activated carbon. The dynamic adsorption process of HCHO was simulated by molecular dynamics (MD). The influence and proportion of OGs on HCHO adsorption were subsequently analyzed using van der Waals and electrostatic interactions, determining differences in formaldehyde adsorption effects across OG types. The carboxyl group exhibits the most robust synergistic adsorption effect on the modified activated carbon. There is a notable alteration in the position and distribution of electrostatic potential extremes observed following carboxyl modification. The calculation results show that the adsorption energy of hydroxyl groups on modified activated carbon is the highest, at −5.07 kcal/mol, with a transfer charge of 0.014 e. Following the introduction of carboxyl groups, the proportion of electrostatic interactions escalated from the initial 24% to 38%. This study will provide new ideas for guiding the design of activated carbon for efficient adsorption of formaldehyde. Methods: The modified activated carbon fragments of three OGs were constructed by Materials Studio and Gaussian software, and the surface electrostatic potential polarity and area distribution, charge change, adsorption energy, and transferred charge of each molecular fragment were calculated. Moreover, cell models of OGs with the same dimensions were constructed to simulate the adsorption amount, heat of adsorption, interaction energy, radial distribution function, and hydrogen-bonding interactions for methane at room temperature and pressure. The results were consistent with the DFT simulations. [ABSTRACT FROM AUTHOR]

Developing low density and efficient dielectric loss materials has become a research hotspot, which can greatly meet the demands of modern radars and settle the problem of electromagnetic wave pollution. Herein, a series of N-doped ordered mesoporous carbon (OMC) materials with different nitrogen content were prepared via a modified self-assembly method and defect engineering in subsequent calcination treatment. It was discovered that the content and type of nitrogen doping can be effectively modulated by the amount of precursor dicyandiamide, resulting in the changes in porous structure, carbon defects, electromagnetic properties, microwave absorption (MA) performance and radar cross section (RCS) reduction values. Remarkably, as-fabricated OMC/N2.5 displays ideal MA performance, whose minimum reflection loss (RL(min)) value reaches −35.3 dB at 7.76 GHz (3.0 mm) and its effective absorption bandwidth reaches 3.52 GHz (10.64–14.16 GHz, 2.0 mm). Furthermore, the optimal RCS reduction values can be obtained as 12.01 dB·m2 when the detection theta is 30°, which validly reduces the chances of being detected by radar. Thus, this work opens up a novel way for the development of lightweight and high-efficiency MA materials.

Being an alien species, Spartina alterniflora has occupied the living space of native animals and plants, causing irreversible damage to the environment. Converting Spartina alterniflora into carbon or its derivatives offers a valuable solution to manage both invasive biomass and an energy shortage. Herein, through a simple activation process, we successfully prepared Spartina alterniflora-derived carbon (SAC) and its N-doped derivative SANC, and used them as metal-free catalysts for an oxygen reduction reaction (ORR). SAC exhibits good electrochemical performance and holds significant potential in catalysis. After N-doping by melamine as a nitrogen source, electronegativity is redistributed in SANC, leading to enhanced performance (a half-wave potential of 0.716 V vs. RHE, and a four-electron transfer pathway with a H2O2 yield of only 2.05%). This work presents a straightforward and cost-effective approach to the usage of obsolete invasive biomass and shows great potential in energy generation.

Herein, highly recoverable, and stable, nitrogen-doped Ti 3 C 2 T x -based sensors are developed for ammonia detection at room-temperature. Ti 3 C 2 T x MXene as a room-temperature gas sensor has two main drawbacks: weak recovery and resistance drift. In this work; Ti 3 C 2 T x nano-sheets were derived from the pre-synthesized Ti 3 AlC 2 by selective aluminum etching using HF acid. The sensors fabricated using pristine Ti 3 C 2 T x had high response toward polar gases, particularly ammonia. The sensors' response to 100 ppm ammonia was 10%. However, they experienced incomplete recovery and baseline resistance drift. To overcome these problems, we introduced a novel method, in which, before fabricating the gas sensors, the surface of synthesized Ti 3 C 2 T x MXene was modified by a nitrogen treatment strategy. In this method, the MXene layers were doped with nitrogen using NH 3 gas at 500 °C for 2 h. In nitrogen-doped Ti 3 C 2 T x -based sensors, both recovery and drift problems disappeared. The response of the nitrogen-doped Ti 3 C 2 T x is 3.7% toward 100 ppm ammonia, which is a notable response for a stable, recoverable, room-temperature gas sensor. [ABSTRACT FROM AUTHOR]

In this paper, Fe3O4@SiO2@TiO2 and N-doped Fe3O4@SiO2@N-TiO2 photocatalysts with magnetic core-shell structures were prepared using a multi-step synthesis method. The materials were analyzed using various techniques, such as X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), selected-area electron diffraction patterns (SAED), and X-ray photoelectron spectroscopy (XPS). The results indicated that the prepared samples had an anatase structure, and N was successfully doped. Fe3O4@SiO2@TiO2 and Fe3O4@SiO2@N-TiO2 with different amounts of nitrogen doping were used for the study of photocatalytic degradation of methyl orange (MO) in pure MO solution, and in MO and Na2SO4 (MO-Na2SO4) mixed solution, respectively. The average photocatalytic degradation rate of MO in pure MO solution with three different batches each of Fe3O4@SiO2@TiO2 and Fe3O4@SiO2@N-TiO2 (3 mL of NH4OH used for doping) under high-pressure mercury lamp irradiation reached 85.25% ± 2.23% and 95.53% ± 0.53%, respectively. The average photocatalytic degradation rate of MO in the MO-Na2SO4 mixed solution with three different batches each of Fe3O4@SiO2@TiO2 and Fe3O4@SiO2@N-TiO2 (3 mL of NH4OH used for doping) under the same irradiation condition reached 90.46% ± 3.33% and 97.79% ± 2.09%, respectively. The results showed that Na2SO4 can promote photocatalytic degradation of MO. The experiment of recycling photocatalysts showed that there was still a good degradation effect after five cycles. Finally, the first-order kinetic model and the photocatalytic degradation mechanism were investigated.

[Display omitted] Aqueous rechargeable zinc-ion batteries (ARZIBs) are promising candidates for fast-charging energy-storage systems. The issues of stronger interactions between Zn2+ and the cathode for ultrafast ARZIBs can be partially addressed by enhancing mass transfer and ion diffusion of the cathode. Herein, via thermal oxidation for the first time, N -doped VO 2 porous nanoflowers with short ion diffusion paths and improved electrical conductivity were synthesized as ARZIBs cathode materials. The introduction of nitrogen derived from the vanadium-based-zeolite imidazolyl framework (V-ZIF) contributes to enhanced electrical conductivity and faster ion diffusion, while the thermal oxidation of the VS 2 precursor assists the final product in exhibiting a more stable three-dimensional nanoflower structure. In particular, the N -doped VO 2 cathode shows excellent cycle stability and superior rate capability with the delivered capacities of 165.02 mAh g−1 and 85 mAh g−1, at 10 A g−1 and 30 A g−1, and the capacity retention of 91.4% after 2200 cycles and 99% after 9000 cycles, respectively. Remarkably, the battery takes less than 10 s to be fully charged at 30 A g−1. Hence, this work provides a new avenue for designing unique nanostructured vanadium oxides and developing electrode materials suitable for ultrafast charging. [ABSTRACT FROM AUTHOR]

Abstract The optical and chiroptical properties of an aza‐HBC‐oct‐[5]helicene have been studied and also modulated by means of protonation or oxidation. In both cases, the generated species shows a new absorption band in the NIR region that is not present in the neutral species. This result enables this N‐doped nanographene to act both as optical and, remarkably, as chiroptical switch since both the CD and CPL can be modulated by external stimuli such as redox or pH changes.

BACKGROUND: Biochar has received much attention for disposal of aqueous organic contaminants because of its great potential in adsorption and catalysis. N‐doped rice husk biochar (N‐BC) was synthesized in this work and used to activate potassium peroxymonosulfate (PMS) to remove different types of dyes. The influence of preparation conditions of N‐BC and reactive conditions on removal rate was discussed in detail. Free radical quenching experiment and electron spin resonance were used to analyze the active species and mechanism in the reaction. RESULTS: N‐BC with abundant graphitic‐N, which is the main form of N to activate PMS, can be obtained by N‐doping with carbamide at 900 °C. The removal rate for new coccine can reach nearly 100% in 30 min. Furthermore, the removal rate can still be maintained at 77.21% after reusing four times only washing with water, and it can be further promoted to 98.78% after annealing treatment at 900 °C. N‐BC has excellent applicability to different types of dyes. CONCLUSION: Consequently, the mechanism is the combination of radical (O2•−) and nonradical (1O2) oxidation. First, the preparation method in this work is relatively simple. Second, the material can adapt to a very wide pH range. Third, the material shows high efficiency at room temperature (the removal rate can reach nearly 100% in 30 min). Fourth, the material shows high efficiency with only a small amount. This study provides a new path of rapid dye water purification using biochar, with simple synthesis, wide pH range adaptability, and high efficiency with only a small amount. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Herein, a novel method, heat mechanochemical synthesis (HMCS), is reported for facile and scalable preparation of electrocatalysts with metallic sites anchored on carbon materials. The method simultaneously provides mechanical energy and heat to drive reaction, by which target metal atoms are efficiently trapped in N‐doped and defect‐rich carbon that prepared in advance (NC). The advantages of this method are: (1) high contents of metals at the outermost surface; (2) unique metal sites formed under collisions with mechanical energy; and (3) not annealed at high temperatures, which would retain some unique active sites on the materials. A series of unitary transition metal (Cr, Mn, Fe, Co, Ni, Cu, or Zn) superficially anchored carbons are obtained via the HMCS. More than this, it is quite convenient to prepare multiple metals, such as combinations among these metals, highly dispersed and anchored on the carbon materials in one time. As a representative, the as‐prepared Fe‐NC (denoted as FeNCHM in context) is investigated in detail as catalyst for ORR and Zn‐air battery applications. The authors envision that the method of HMCS provides a good support of surface engineering for preparation of metals sites containing carbon at large scale. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the photoinduced properties of nitrogen-doped titanium dioxide (N-TiO2) against the Salmonella ser. Typhimurium bacterial biofilm, under visible-light irradiation. The capability of N-TiO2 nanoparticles working as multipurpose materials with antimicrobial applications, as well as environmental ones, was therefore investigated. The sol–gel method was used to synthesize N-TiO2 particles, which were then characterized by Fourier-transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), Brunauer–Emmett–Teller (BET) analysis of surface area, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), and transmission electron microscopy (TEM). The results showed that the particles formed were nano-sized and had the expected Ti-O bonds and the presence of elemental N. The as-produced N-TiO2 nanoparticles (NPs) were tested for their antimicrobial activity. The antibacterial photocatalytic testing was performed under visible-light irradiation, on Salmonella Typhimurium biofilm. To form the biofilm, stainless steel (ss) coupons were incubated with three different strains of Salmonella Typhimurium bacteria for 48 h at 15 °C in tryptone soy broth (TSB). After the biofilm's formation, the coupons were placed on a horizontal, rectangular, batch, equipped with a vis-LED irradiation source reactor in the presence of N-TiO2 NPs. After 1, 2, and 3 h of irradiation, sampling of the bacterial population was assessed. The results showed an evident inhibition of proliferation under light irradiation when the N-TiO2 was present, compared to the non-irradiated NPs. It is noteworthy that, during the first 2 h, the TiO2 NPs specimens tended to attract more bacteria on their surface then the control specimens, due to their higher available surface area, which worked as a shelter. There were ~6% viable (remaining) Salmonella cells after the first hour of visible-light irradiation with N-TiO2 NPs. [ABSTRACT FROM AUTHOR]

Non-precious-metal-based oxygen reduction reaction (ORR) catalysts hold great prospects for rechargeable metal–air batteries and reversible electrolyzer/fuel cell systems. Among the various earth-abundant and noble-metal-free catalysts, Mn- and Ni-based single-atom catalysts (SACs) are attracting attention for ORRs. Herein, we designed a facile and efficient strategy to obtain Mn/Ni dual-metal single-atom catalysts, in which atomic Mn and Ni sites were dispersed on nitrogen-doped porous carbon. The optimized Mn/Ni catalysts showed excellent ORR electrocatalytic performance with a half-wave potential of 0.803 V, comparable to that of commercial Pt/C catalysts. Meanwhile, the electron transfer number was determined to be 3.9, indicating a good four-electron reaction process. The excellent electrocatalytic performance was attributed to the N-doped porous carbon structure with a large specific surface area, which afforded abundant active sites to anchor the single Mn and Ni atoms. [ABSTRACT FROM AUTHOR]

The primary objective of this research is to propose and compile a specific protocol for photocatalytic measurements of modified TiO2 particles under visible-light irradiation. Nitrogen-modified titanium dioxide (N-TiO2) powder was synthesized by the sol–gel method and characterized by X-ray Diffraction Analysis (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Raman Spectroscopy (micro-Raman), and Ultraviolet–visible Spectroscopy (UV-Vis). Photocatalytic tests were performed on a specially designed photocatalytic batch reactor to test the ability of the powder to degrade hazardous toxic compounds. Via the Taguchi method, nine experiments (L9) were compiled to examine the factors that affect the photocatalytic activity of the nano-sized powder. The N-TiO2 particles were characterized by the dominance of the crystalline anatase phase, exhibiting crystals in the nano-scale. The Taguchi method was designed to control four selected parameters (pollutant selection among azo dyes, amount of catalyst to pollutant, distance of the photocatalytic cell from the radiation source, and time protocol) with three levels/options each. Conclusions were drawn regarding the way each parameter affects the final degradation of the pollutant. The parameter that proved to affect the degradation of the pollutant to a greater extent was the choice of pollutant, followed by the amount of catalyst. The other two factors almost slightly affect the process, with a similar percentage. Taking into account the abovementioned results, a photocatalytic protocol for testing TiO2 nano-powder activity under visible light irradiation is proposed by using a batch, horizontal, rectangular, vis-LED equipped reactor with reflective walls. [ABSTRACT FROM AUTHOR]

It is necessary that develop broad spectrum responsive and noble-metal-free photo-catalysts to produce hydrogen. Herein, a novel nitrogen doped amorphous CoP with carbon coating (N–CoP@C) photo-catalyst was prepared by phosphating the Co-alanine complex precursor for wide spectrum photocatalytic H 2 production. Nitrogen doping can adjust the electronic structure, promote photogenerated carrier separation, and enhance electronic density. The improvement of photocatalytic hydrogen evolution activity is due to the porous structure and surface carbon layer of amorphous N–CoP@C. The porous and thin slice structure can increase the specific surface area, thus providing more active sites and separating surface charges. The carbon layer can be used as an electron acceptor to suppress charge recombination and improve photocatalytic performance. The amorphous N–CoP@C-4 exhibits the highest hydrogen evolution rate of 60.91 μmol h−1 under visible light irradiation with EY as a photosensitizer and TEOA as an electron donor, which is about 46.7 and 2.8 times higher than Co-alanine and CoP, respectively. In particular, a high photocatalytic reaction stability was achieved over N–CoP@C-4 catalyst. This work provides an effective strategy for construction N–CoP@C to improve the photocatalytic activity. A novel amorphous N–CoP@C photocatalyst was prepared by phosphating the Co-alanine complex precursor for wide spectrum photocatalytic H 2 production under light irradiation. The coating of carbon layer on the surface increased the electron density on the catalyst surface and accelerated the charge transfer efficiency. The photocatalytic hydrogen evolution performance of N–CoP@C catalyst was improved by the synergistic effect of N doping and coating of surface carbon layer. [Display omitted] • Amorphous N–CoP@C photocatalyst was prepared by phosphating Co-alanine complex. • Adjusting electronic structure by doping N to accelerate charge separation efficiency. • Carbon coating increased the surface charge transfer rate of N–CoP@C. • Amorphous structure provides more active sites for hydrogen production. • EY-sensitized N–CoP@C-4 exhibits an outstanding photocatalytic H 2 evolution rate. [ABSTRACT FROM AUTHOR]

[Display omitted] Accelerating the sluggish anode reaction in a Zn–air battery can improve its energy efficiency, but the large-scale development of this battery is hindered by the lack of bifunctional catalysts. Herein, we designed a one-step carbonization strategy for synthesizing monodispersed Co nanoparticles supported on N -doped carbon nanotube (Co/CNT), which shows excellent bifunctional electrocatalytic performance with long-term durability for oxygen reduction reaction/oxygen evolution reaction. The formation of carbon substrates from the carbonization of nitrogenous organic molecules are benefit to capture more Co nanoparticles though strong metal–substrate interaction, then construct high-density effective active sites of the Lewis base for accelerating the electrocatalytic reaction process. To verify its superior performance, a rechargeable Zn–air battery with a Co/CNT air electrode was subsequently constructed. The battery exhibits an open-circuit voltage of 1.41 V and a specific discharge capacity of 835.2 mAh/g Zn , which can be continuously charged and discharged with good cycle stability. Our study provides a new strategy for developing various practical carbon-based non-noble metallic bifunctional electrocatalysts with promising performance in electrocatalysis and batteries to achieve the target of carbon neutrality. [ABSTRACT FROM AUTHOR]

Laser direct writing of polyimide (PI) film to induce porous graphene as a flexible electrode facilitates the development of efficient, low-cost, and large-scale preparation of flexible planar micro-supercapacitors (MSCs). Nevertheless, current flexible MSCs based on laser-induced graphene (LIG) face bottlenecks such as poor LIG electrode wettability, inhomogeneous doping of heterogeneous components, and limited electrochemical performance. In view of this, a simple and effective process for in situ fabrication of flexible FeOx nanoparticles embedded N-doped LIG (FeOx@NLIG) electrode is developed by laser direct writing in this study. The as-assembled in-plane FeOx@NLIG MSCs exhibit an excellent areal specific capacitance of 13.82 mF cm−2, a remarkable energy density of 1.228 mW h cm−2 at a high power density of 0.024 mW cm−2, good flexibility, and conspicuous cycling stability. Besides, these high-performance in-plane FeOx@NLIG MSCs as a vital micro-energy storage component can be easily miniaturized, modularized, and integrated to suit customized needs of wearable electronics due to great advantages in terms of identicality and stability of the as-fabricated FeOx@NLIG. [ABSTRACT FROM AUTHOR]

For achieving the goal of peaking carbon dioxide emissions and achieving carbon neutrality, developing hydrogen energy, the green and clean energy, shows a promising perspective for solving the energy and ecological issues. Herein, firstly, we used the hydrothermal method to synthesize the ZnS(en)0.5 as the precursor. Then, ZnS/ZnO composite was obtained by the in situ transformation of ZnS(en)0.5 with heat treatment under air atmosphere. The composition, optical property, morphology, and structural properties of the composite were characterized by X-ray photoemission spectroscopy (XPS), Ultraviolet-visible absorption spectra (Uv-vis Abs), Scanning electron microscopy (SEM) and Transmission electron microscopy image (TEM). Moreover, the content of ZnO in ZnS/ZnO was controlled via adjustment of the calcination times. The visible-light response of ZnS/ZnO originated from the in situ doping of N during the transformation of ZnS(en)0.5 to ZnS/ZnO under heat treatment, which was verified well by XPS. Photocatalytic hydrogen evolution experiments demonstrated that the sample of ZnS/ZnO-0.5 h with 6.9 wt% of ZnO had the best H2 evolution activity (1790 μmol/h/g) under visible light irradiation (λ > 400 nm), about 7.0 and 12.3 times that of the pure ZnS and ZnO, respectively. The enhanced activities of the ZnS/ZnO composites were ascribed to the intimated hetero-interface between components and efficient transfer of photo-generated electrons from ZnS to ZnO. [ABSTRACT FROM AUTHOR]

The dopants of sulfur, nitrogen, or both, serving as the active sites, into the graphitic framework of graphene is an efficient strategy to improve the electrochemical performance of electrochemical membrane filtration. However, the covalent bonds between the doped atoms and the substrate that form different functional groups have a significant role in the specific activity for pollutant degradation. Herein, we found that the singly doped heteroatom graphene (NG and SG) achieved superior removal efficiency of pollutants as compared with that of the double doped heteroatom graphene (SNG). Mechanism studies showed that the doped N of NG presented as graphitic N and substantially increased electron transfer, whereas the doped S of SG posed as -C-SOx-C- provided more adsorption sites to improve electrochemical performance. However, in the case of SNG, the co-doped S and N cannot form the efficient graphitic N and -C-SOx-C- for electrochemical degradation, resulting in a low degradation efficiency. Through the fundamental insights into the bonding of the doped heteroatom on graphene, this work furnishes further directives for the design of desirable heteroatom graphene for membrane filtration. [ABSTRACT FROM AUTHOR]

The chemical composition and surface groups of the carbon support affect the adsorption capacity of toluene. To investigate the effect of catalyst substrate on the catalytic performance, two different plant biomasses, banana peel and sugarcane peel, were used as carbon precursors to prepare porous carbon catalyst supports (Cba, Csu, respectively) by a chemical activation method. After decorating PtCo3 nanoparticles onto both carbon supports (Cba, Csu), the PtCo3-su catalyst demonstrated better catalytic performance for toluene oxidation (T100 = 237 °C) at a high space velocity of 12,000 h−1. The Csu support possessed a stronger adsorption capacity of toluene (542 mg g−1), resulting from the synergistic effect of micropore volume and nitrogen-containing functional groups, which led to the PtCo3-su catalyst exhibiting a better catalytic performance. Moreover, the PtCo3-su catalyst also showed excellent stability, good water resistance properties, and high recyclability, which can be used as a promising candidate for practical toluene catalytic combustion. [ABSTRACT FROM AUTHOR]

N-doped hierarchical porous carbon sheet was prepared through calcination of a sodium alginate film precursors containing Zn-2-methylimidazole coordination complex. The film precursors could be obtained at room temperature. The introduction of coordination complex cannot cause the change of sheet morphology, but it can promote the generation of large pore structure. Due to the hierarchical porous structure and N doping, the carbon materials present excellent electrochemical behaviors when used as supercapacitor electrode materials. It exhibited a high specific capacitance of 210.4 F g−1 at 2 A g−1 in a two-electrode system with a capacitance retention of 83.4% over 10,000 cycles. [Display omitted] • N-doped hierarchical porous carbon sheets were synthesized from biomass. • The film precursors could be obtained at room temperature. • The obtained carbon material exhibited excellent supercapacitor performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nitrogen-doped does not broaden the optimal pore size for CH 2 O adsorption. • Mechanism of adsorption by nitrogen-doped with different pore sizes are clarified. • The limiting pore size of activated carbon adsorption CH 2 O is 14 Å. • Nitrogen-doped have ability to increase the limiting pore size to 16 Å. The pore size range of activated carbon has an important effect on formaldehyde adsorption, while nitrogen-doped can promote formaldehyde adsorption, but the mechanism of nitrogen-doped on formaldehyde adsorption at different pore size range has not been elaborated clearly. Therefore, this paper investigates the effect of range on formaldehyde adsorption at different pore size scales. Through simulation, it is concluded that nitrogen-doped does not broaden the optimal pore size for formaldehyde adsorption and the optimal pore size is still 6 Å, but nitrogen-doped can improve the non-bonding interactions between formaldehyde molecules and activated carbon by changing the electrostatic distribution on the surface of activated carbon, which enhances the adsorption of formaldehyde molecules. In addition, the non-bonding interaction between formaldehyde molecules and activated carbon decreases with increasing pore size, whereas nitrogen-doped enhances the non-bonding interaction between formaldehyde molecules and activated carbon, and therefore nitrogen-doped improves the limiting pore size of activated carbon for formaldehyde adsorption. [ABSTRACT FROM AUTHOR]

The physical properties and chemical compositions of porous carbons are crucial factors in determining their effectiveness in adsorbing CO 2. Cellulose-based porous carbon has emerged as an outstanding candidate adsorbent for CO 2 capture. The research involved the creation of hierarchically nitrogen-doped porous carbon (HNC) using a 3D cellulose alcogel (CA) as substrate, which was prepared through a thermal introduced phase separation (TIPS) method combined with hydrolysis treatment. The plentiful functional groups of CA offered abundant growth sites for the introduction of ZIF-8 crystals. CA/ZIF-8 composite alcogel (CZA) with greater surface area and superior thermal stability compared to CA was successfully fabricated and used as precursor for the production of HNC. The important effects of microporosity and surface chemistry of HNC samples on CO 2 capture were discussed in-depth. HNC-350–850 displayed a hierarchically porous structure with a large number of micropores and abundant N/O/Zn-doped functional groups, exhibiting high CO 2 uptakes at 1 bar (3.56 mmol/g at 25 °C), good IAST CO 2 /N 2 (15/85, V/V) selectivity of 16.31 at 25 °C, and outstanding regenerability with ∼100 % CO 2 adsorption capacity retained after ten cycles. In the two-component CO 2 /N 2 (15/85, V/V) competitive adsorption process, the maximum breakthrough periods for CO 2 (433.1 s) is significantly longer than that of N 2 (3.8 s). The CO 2 breakthrough adsorption capacity reached 1.79 mmol/g at 25 °C and 1 bar with the separation coefficient of 45.8 for CO 2 over N 2. These results confirmed that HNC, in addition to having excellent CO 2 /N 2 selectivity, demonstrated good feasibility for practical use. The green and practicable synthetic route described in this study is not only expected to offer novel adsorbents for high performance CO 2 capture, but also provide a new theoretical foundation for the development of cellulose-based porous materials. [Display omitted] • Cellulose/ZIF-8 composite alcogel showed high surface area and good thermal stability. • Hierarchically N-doped porous carbon displayed remarkable CO 2 adsorption performance. • Microporosity and N-containing functional group had positive effects on CO 2 capture. • A green and feasible route was provided for designing novel cellulose-based adsorbents. [ABSTRACT FROM AUTHOR]

Designing nonprecious metal-based heteroatom-doped electrocatalysts with low overpotential for efficient hydrogen production via oxygen evolution reactions presents significant challenges. We fabricated and carbonized an N-doped bimetallic phosphide (CeFeP) in this study. Scanning electron microscopy and transmission electron microscopy analyses revealed the formation of a uniform spherical nanoparticle morphology, while structural changes were evidenced in the carbonization step at temperatures of 300 and 700 ℃ by XRD analysis. The synthesized materials were then coated onto carbon paper electrodes in a basic medium, and their performance in the oxygen evolution reaction was evaluated. The results show that the N-doped bimetallic phosphide material carbonized at 700 ℃ has enhanced catalytic activity, as indicated by its low overpotential of 155 mV and Tafel slope of 57 mV/dec, respectively, for a standard current density of 10 mA/cm2. The catalytic performance of the N-doped CeFeP sample was significantly higher than that of undoped CeFeP and the single metal phosphide, thereby indicating it has significant potential for practical applications. [Display omitted] • SEM and TEM reveal uniform spherical morphology, indicating efficient design. • XRD shows spinel structure, critical for electrocatalysis. • N@CeFeP-1 shows low overpotential and Tafel slope of 155 mV and 57 mV/dec. • N@CeFeP-1 has batter activity compare to un-doped CeFeP and single metal phosphide catalysts. • N@CeFeP-1 is a promising catalyst for hydrogen production. [ABSTRACT FROM AUTHOR]

The fabrication of Pt-free electrocatalysts with outstanding activity is crucial for reducing the overpotential of the hydrogen evolution reaction (HER) and advancing the next generation of energy technologies. This study introduced a scalable one-pot pyrolysis approach for fabricating N-doped Ru/Mo 2 C (MCNR x) for HER. The MCNR 1 catalyst offered several advantages for electrocatalytic applications and beyond. The N-doped Ru/Mo 2 C prevented the agglomeration of Mo 2 C nanomaterials and improved their electronic conductivity. Moreover, the Ru metal was uniformly distributed, providing a large number of active catalytic sites, and the enhanced crystallinity and conductive surfaces generated from the trimesic acid create mass electron migration and facilitate the presence of active centers. The MCNR 1 electrocatalyst, designed with the abovementioned advantages, had exceptional performance for HER across a broad pH range. For instance, it achieved a current density of 10 mA cm−2 with an overpotential of 35 mV in 1.0 M KOH, 44 mV in 0.5 M H 2 SO 4 , and 196 mV in 1.0 M phosphate-buffered saline (PBS). Furthermore, the electrocatalyst had exceptional long-term stability across all pH levels compared to Pt/C. The synthetic approach devised in this study can be employed for various cost-effective replacements for Pt-based electrocatalysts for HER. [Display omitted] • This research explores N-doped Ru/Mo 2 C for outstanding HER. • The HER applications of this research are addressed across a broad pH range. • The exceptional stability across all pH levels has been extensively studied. • This study can be employed for cost-effective HER catalysts. [ABSTRACT FROM AUTHOR]

In this work, the eco-friendly N-doped carbon dots KF-CDs and A-CDs were derived from kiwifruit by a simple one-step hydrothermal strategy at 180 °C for 6 h. KF-CDs have a high fluorescence quantum yield (27.85%), it is obviously rapid quenched by Fe3+, and have a good linear relationship from 1 to 8.26 µM (the detection limit was 0.077 µM). Basic red 9 is extensively used in biological, environmental and industry. Although it makes a great contribution to the economy, its toxicity should be taken seriously, especially with harmful metal ions. Within 2 h, A-CDs could degrade basic red 9 with degradation efficiency 89.6%, even though there was a stable compound formed with Fe3+ that the degradation efficiency was up to 88.3%. The results complement the research blank of carbon dots in catalytic degradation of basic red 9. [ABSTRACT FROM AUTHOR]

• Triple engineering strategy to boost the kinetics of Zn2+ in vanadium oxide. • N-doped V 2 O 5-x ·nH 2 O cathode is prepared by a simple and effective method.. • The N-doped V 2 O 5-x ·nH 2 O cathode delivers high capacity and cycle performance. • Assembled cylindrical ZIB demonstrate excellent cycling performance and safety. Vanadium oxide is one of promising cathode materials for aqueous zinc-ion batteries (ZIBs), but the low electrical conductivity and slow ion diffusion kinetics of vanadium oxide lead to low practical capacity and poor cycling life, which limits further commercialization development. Herein, this study proposes a triple engineering strategy of N-doping, oxygen vacancies and crystal water to achieve the high-performance of V 2 O 5 by a simple stirring method. N doping can improve the electrical conductivity of the materials, oxygen vacancies can modulate the electronic structure, and the crystal water can effectively shield the electrostatic effect. First-principles calculations confirmed that the incorporation of the triple engineering strategies can effectively reduce of the energy band gap and Zn2+ diffusion barrier of V 2 O 5 , and promote the intercalation dynamics of Zn2+. As a result, the prepared N-doped V 2 O 5-x ·nH 2 O achieves an outstanding specific capacity of 607.74 mAh/g at 0.1 A/g, and cycling stability. Moreover, based on the above advantages, the practical 21700-type cylindrical battery assembled with this N-doped V 2 O 5-x ·nH 2 O cathode and Zn foil anode, presenting a maximum capacity of 393.5 mAh at 0.4 A. This high performance of vanadium oxide cathode shows a good practical prospect in aqueous cylindrical ZIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] Nitrogen-doped titania (TiO 2 -N) was synthesized and tested, both in unmodified form and with grafted Cu and Pt particles, in the reaction of photocatalytic oxidation of benzene under visible light irradiation at temperatures of 40, 100 and 140 °C. The results obtained indicate additional thermal activation of the reaction over Pt-containing samples with the maximum difference between the total and thermal activities at 100–120 °C. As modifiers, both platinum and copper separately improve the photoactivity of TiO 2 -N, but when used together, their effects do not add up, and the photocatalyst behaves like a Pt-modified sample. [ABSTRACT FROM AUTHOR]

Functionalization of carbon supports with heteroatom dopants is now widely regarded as a promising route for stabilizing and strengthening the interactions between the support and metal catalysts. Tuning the type and density of heteroatom dopants allows for the tailoring of nanoscale catalyst–support interactions; however, an understanding of these phenomena has not yet been fully realized because of the complexity of the system. In this work, computational modeling, materials synthesis, and advanced nanomaterial characterization are used to systematically investigate the intriguing effect of the two most common nitrogen functionalities in the carbon-based supports on the interactions with selected transition metals toward realizing catalytic applications. Specifically, this study utilized density functional theory to evaluate adsorption energies and modes of adsorption for 12 metals located in groups 8–11 and periods 4–6 with pyridinic and graphitic N defects. Based on these results, further electronic structure investigation of the period 4 metals was conducted to elucidate periodic group trends. Experimental work included synthesis and nanomaterial characterization of a subset of materials featuring three metals each supported on two types of N-doped carbon supports and undoped graphene. Characterization of nanomaterials with scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy confirmed that N functionalities enhanced the interactions with the selected transition metals when compared to the undoped support and demonstrated that the nature of the defect influences these interactions. Both computations and experiments agreed that Fe and Co are biased toward the graphitic sites over pyridinic sites, while Ni has an affinity to both defects without a statistically significant preference. This work established a correlation between computational and experimental work and a framework that can be expanded to other metals and alternative dopants beyond nitrogen in tailoring nanoscale catalyst–support interactions for a breadth of catalytic applications. [ABSTRACT FROM AUTHOR]

Coal is a typical fossil fuel and it is also a natural carbon material, therefore, converting it to functional carbon materials is an effective way to enhance the economic advantages of coal. Here, ultrathin N-doped carbon nanosheets were prepared from low-cost coal via a handy and green molten-salt method, which shown excellent performance for lithium-ion batteries (LIBs). The formation mechanism of ultrathin nanosheets was studied in detail. The eutectic molten salts possess low melting points and become a strong polar solvent at the calcined temperature, making the acidified coal miscible with them in very homogeneously state. Therefore, they can play a gigantic role in in situ pore-forming during the carbonization and induce the formation of ultrathin nanosheets due to the salt ions. Simultaneously, the ultrathin N-doped carbon nanosheets with rich defects and controllable surface area was smoothly prepared without any more complex process while revealing brilliant electrochemical performance due to rich ion diffusion pathways. It delivers reversible capacity of 727.0 mAh gâˆ'1 at 0.2 A gâˆ'1 after 150 cycles. Thus, the molten-salt method broadens the avenue to construct porous carbon materials with tailor-made morphologies. Equally important, this approach provides a step toward the sustainable materials design and chemical science in the future. [ABSTRACT FROM AUTHOR]

N-enriched porous carbons have played an important part in CO2 adsorption application thanks to their abundant porosity, high stability and tailorable surface properties while still suffering from a non-efficient and high-cost synthesis method. Herein, a series of N-doped porous carbons were prepared by a facile one-pot KOH activating strategy from commercial urea formaldehyde resin (UF). The textural properties and nitrogen content of the N-doped carbons were carefully controlled by the activating temperature and KOH/UF mass ratios. As-prepared N-doped carbons show 3D block-shaped morphology, the BET surface area of up to 980 m2/g together with a pore volume of 0.52 cm3/g and N content of 23.51 wt%. The optimal adsorbent (UFK-600-0.2) presents a high CO2 uptake capacity of 4.03 mmol/g at 0 °C and 1 bar. Moreover, as-prepared N-doped carbon adsorbents show moderate isosteric heat of adsorption (43–53 kJ/mol), acceptable ideal adsorption solution theory (IAST) selectivity of 35 and outstanding recycling performance. It has been pointed out that while the CO2 uptake was mostly dependent on the textural feature, the N content of carbon also plays a critical role to define the CO2 adsorption performance. The present study delivers favorable N-doped carbon for CO2 uptake and provides a promising strategy for the design and synthesis of the carbon adsorbents. [ABSTRACT FROM AUTHOR]

Electrochemical determination of tert-butylhydroquinone (TBHQ) is vital to food safety due to negative health effects; however, bare electrode of traditional electrochemical sensors generally has a narrow linear range and low sensitivity, limiting their practical application. Accordingly, the nano-architecture fabricated with N-doped TiO2–carbon nano-composites (TiO2/NC) is prepared by the thermolysis of NH2 functionalized MIL-125(Ti) metal–organic frameworks (NH2-MIL-125(Ti)). TiO2/NC composites are firstly developed as the electrochemical material for electrochemical determination of TBHQ. The TiO2/NC composites with a highly porous structure, excellent conductivity and electron transportation, and large surface area show remarkable electrochemical oxidation ability for TBHQ. Under optimal conditions, TiO2/NC composite-modified electrode presents a broader linear response to TBHQ concentration of 0.05–100 μM with the detection limit as low as 4 nM (S/N = 3). Finally, the sensor platform is implemented directly to determine TBHQ in edible oil for evaluation of its practical application. TiO2/NC composites sensor fabricated perform larger linear range with high sensitivity and anti-interference properties, which can be used as a potential for electrochemical determination of TBHQ. [ABSTRACT FROM AUTHOR]

Developing artificial nanoparticles with peroxidase‐like activity have attracted great interests because their catalytic activity is not easy to lose under harsh conditions compared with natural enzymes. In this work, the N‐doped carbon dots (CDs) were prepared; it was found that the N‐doped CDs showed high peroxidase‐like catalytic activity towards the reaction system of hydrogen peroxide:3,3′,5,5′‐tetramethylbenzidine (TMB). The catalytic mechanism of the N‐doped CDs was explored using electron spin resonance spectra, cyclic voltammetry methods and simulation of density functional theory calculations. This work can offer a new feasible method for synthesizing N‐doped carbon quantum dots used as artificial peroxidases in biological and environment applications. [ABSTRACT FROM AUTHOR]