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Zhang Y, Tang Y, Liang R, Zhong L, Xu J, Lu H, Xu X, Han T, Bao Y, Ma Y, Gan S, Niu L. Carbon-Based Transducers for Solid-Contact Calcium Ion-Selective Electrodes: Mesopore and Nitroge n-Doping Effects. MEMBRANES 2022; 12:903. [PMID: 36135922 PMCID: PMC9505166 DOI: 10.3390/membranes12090903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/07/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
Solid-contact ion-selective electrodes (SC-ISEs) exhibit great potential in the detection of routine and portable ions which rely on solid-contact (SC) materials for the transduction of ions to electron signals. Carbon-based materials are state-of-the-art SC transducers due to their high electrical double-layer (EDL) capacitance and hydrophobicity. However, researchers have long searched for ways to enhance the interfacial capacitance in order to improve the potential stability. Herein, three representative carbon-based SC materials including nitrogen-doped mesoporous carbon (NMC), reduced graphene oxide (RGO), and carbon nanotubes (CNT) were compared. The results disclose that the NMC has the highest EDL capacitance owing to its mesopore structure and N-doping while maintaining high hydrophobicity so that no obvious water-layer effect was observed. The Ca2+-SC-ISEs based on the SC of NMC exhibited high potential stability compared with RGO and CNT. This work offers a guideline for the development of carbon-material-based SC-ISEs through mesoporous and N-doping engineering to improve the interfacial capacitance. The developed NMC-based solid-contact Ca2+-SC-ISE exhibited a Nernstian slope of 26.3 ± 3.1 mV dec-1 ranging from 10 μM to 0.1 M with a detection limit of 3.2 μM. Finally, a practical application using NMC-based SC-ISEs was demonstrated through Ca2+ ion analysis in mineral water and soil leaching solutions.
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Abd El-Lateef HM, Khalaf MM, Dao VD, Mohamed IMA. Electrochemical Impedance Investigation of Dye-Sensitized Solar Cells Based on Electrospun TiO 2 Nanofibers Photoanodes. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6175. [PMID: 36079556 PMCID: PMC9457904 DOI: 10.3390/ma15176175] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/26/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
This work investigates an electrochemical impedance analysis based on synthesized TiO2 nanofibers (NFs) photoanodes, which were fabricated via electrospinning and calcination. The investigated photoanode substrate NFs were studied in terms of physicochemical tools to investigate their morphological character, crystallinity, and chemical contents via scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analyses. As a result, the studied photoanode substrate NFs were applied to fabricate dye-sensitized solar cells (DSCs), and the electrochemical impedance analysis (EIS) was studied in terms of equivalent circuit fitting and impacts of N-doping, the latter of which was approved via XPS analysis. N-doping has a considerable role in the enhancement of charge transfers, which could be due to the strong interactions between active-site N atoms and the used photosensitizer.
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Wang T, Fu Q, Wang S, Xing D, Bai Y, Wang S. Enhanced water-resistance of Mn-based catalysts for ambient temperature ozone elimination: Roles of N and Pd modification. CHEMOSPHERE 2022; 303:135014. [PMID: 35598789 DOI: 10.1016/j.chemosphere.2022.135014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 05/12/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
Cryptomelane-type MnO2 catalysts own excellent ozone (O3) decomposition performance. However, it is urgent to improve their long-term stability at ambient temperature, especially under the presence of water. In the present study, a modification strategy was proposed by N-doping and the successive Pd introduction. The N-doping of MnO2 by NH4Cl (NH4-MnO2) can increase its activity for O3 decomposition. And almost 100% O3 decomposition was achieved within 24 h under water-free atmosphere at ambient temperature (25 °C). Successive Pd addition further promoted the water-resistance of NH4-MnO2 catalyst under high humidity (RH > 90%). In combination with detailed characterizations, it indicated that the enhancements on stability and water-resistance were attributed to synergistic effect among acid sites, oxygen defects and Pd clusters. Finally, the decomposition mechanism of gaseous O3 was proposed based on three decisive active sites above.
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Yang C, Wang Z, Li Z, Pan Y, Jiang L, Li C, Wang C, Sun Q. Nitrogen Disturbance Awakening the Intrinsic Activity of Nickel Phosphide for Boosted Hydrogen Evolution Reaction. CHEMSUSCHEM 2022; 15:e202200072. [PMID: 35588238 DOI: 10.1002/cssc.202200072] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 05/09/2022] [Indexed: 06/15/2023]
Abstract
Nickel phosphide (Ni2 P) has emerged as a promising candidate to substitute Pt-based catalysts for hydrogen evolution reaction (HER) due to the hydrogenase-like catalytic mechanism and concomitantly low cost. However, its catalytic activity is still not comparable to that of noble-metal-based catalysts, and innovative strategies are still urgently needed to further improve its performance. Herein, a self-supported N-doped Ni2 P on Ni foam (N-Ni2 P/NF) was rationally designed and fabricated through a facile NH4 H2 PO2 -assisted gas-solid reaction process. As an HER catalyst in alkaline medium, the obtained N-Ni2 P/NF revealed excellent electrocatalytic performance with a distinctly low overpotential of 50 mV at 10 mA cm-2 , a small Tafel slope of 45 mV dec-1 , and long-term stability for 25 h. In addition, the spectroscopic characterizations and density functional theory calculations confirmed that the incorporation of N regulated the original electronic structure of Ni2 P, enhanced its intrinsic catalytic property, optimized the Gibbs free energy of reaction intermediates, and ultimately promoted the HER process. This work provides an atomic-level insight into the electronic structure modulation of metal phosphides and opens an avenue for developing advanced transition metal phosphides-based catalysts.
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Dorontic S, Bonasera A, Scopelliti M, Markovic O, Bajuk Bogdanović D, Ciasca G, Romanò S, Dimkić I, Budimir M, Marinković D, Jovanovic S. Gamma-Ray-Induced Structural Transformation of GQDs towards the Improvement of Their Optical Properties, Monitoring of Selected Toxic Compounds, and Photo-Induced Effects on Bacterial Strains. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:nano12152714. [PMID: 35957147 PMCID: PMC9370814 DOI: 10.3390/nano12152714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 06/03/2023]
Abstract
Structural modification of different carbon-based nanomaterials is often necessary to improve their morphology and optical properties, particularly the incorporation of N-atoms in graphene quantum dots (GQDs). Here, a clean, simple, one-step, and eco-friendly method for N-doping of GQDs using gamma irradiation is reported. GQDs were irradiated in the presence of the different ethylenediamine (EDA) amounts (1 g, 5 g, and 10 g) and the highest % of N was detected in the presence of 10 g. N-doped GQDs emitted strong, blue photoluminescence (PL). Photoluminescence quantum yield was increased from 1.45, as obtained for non-irradiated dots, to 7.24% for those irradiated in the presence of 1 g of EDA. Modified GQDs were investigated as a PL probe for the detection of insecticide Carbofuran (2,2-Dimethyl-2,3-dihydro-1-benzofuran-7-yl methylcarbamate) and herbicide Amitrole (3-amino-1,2,4-triazole). The limit of detection was 5.4 μmol L-1 for Carbofuran. For the first time, Amitrole was detected by GQDs in a turn-off/turn-on mechanism using Pd(II) ions as a quenching agent. First, Pd(II) ions were quenched (turn-off) PL of GQDs, while after Amitrole addition, PL was recovered linearly with Amitrole concentration (turn-on). LOD was 2.03 μmol L-1. These results suggest that modified GQDs can be used as an efficient new material for Carbofuran and Amitrole detection. Furthermore, the phototoxicity of dots was investigated on both Gram-positive and Gram-negative bacterial strains. When bacterial cells were exposed to different GQD concentrations and illuminated with light of 470 nm wavelength, the toxic effects were not observed.
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Geng L, Jia Y, Zhang H, Cui C, Luo Z. Plasma-Assisted Dinitrogen Activation on Small Cobalt Clusters: Co 4 N 9 + with Enhanced Stability. Chemphyschem 2022; 23:e202200288. [PMID: 35689533 DOI: 10.1002/cphc.202200288] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/23/2022] [Indexed: 11/12/2022]
Abstract
We have performed a study on the accommodation of nitrogen doping toward superatomic states of transition metal clusters. By reacting cobalt clusters with N2 in the presence of plasma radiation, a large number of odd-nitrogen clusters were observed, typically Co3 N2m-1 + (m=1-5) and Co4 N2m-1 + (m=1-6) series, showing N≡N bond cleavage in the mild plasma atmosphere. Interestingly, the Co3 N7 + , Co4 N9 + , and Co5 N9 + clusters exhibit prominent mass abundances. First-principles calculation results elucidate the stability of the diverse cobalt nitride clusters and find unique stability of Co4 N9 + with a swallow-kite structure of which four coordinated N2 molecules causes a significantly enlarged HOMO-LUMO gap, while the single N atom doping gives rise to superatomic states of 1S2 1P3 ||1D0 . We reveal an efficient dinitrogen activation strategy by reacting multiple N2 molecules with cobalt clusters under a plasma atmosphere.
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Cui G, Zeng Y, Wu J, Guo Y, Gu X, Lou XW(D. Synthesis of Nitrogen-Doped KMn 8 O 16 with Oxygen Vacancy for Stable Zinc-Ion Batteries. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2106067. [PMID: 35142449 PMCID: PMC8981436 DOI: 10.1002/advs.202106067] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Indexed: 05/20/2023]
Abstract
The development of MnO2 as a cathode for aqueous zinc-ion batteries (AZIBs) is severely limited by the low intrinsic electrical conductivity and unstable crystal structure. Herein, a multifunctional modification strategy is proposed to construct N-doped KMn8 O16 with abundant oxygen vacancy and large specific surface area (named as N-KMO) through a facile one-step hydrothermal approach. The synergetic effects of N-doping, oxygen vacancy, and porous structure in N-KMO can effectively suppress the dissolution of manganese ions, and promote ion diffusion and electron conduction. As a result, the N-KMO cathode exhibits dramatically improved stability and reaction kinetics, superior to the pristine MnO2 and MnO2 with only oxygen vacancy. Remarkably, the N-KMO cathode delivers a high reversible capacity of 262 mAh g-1 after 2500 cycles at 1 A g-1 with a capacity retention of 91%. Simultaneously, the highest specific capacity can reach 298 mAh g-1 at 0.1 A g-1 . Theoretical calculations reveal that the oxygen vacancy and N-doping can improve the electrical conductivity of MnO2 and thus account for the outstanding rate performance. Moreover, ex situ characterizations indicate that the energy storage mechanism of the N-KMO cathode is mainly a H+ and Zn2+ co-insertion/extraction process.
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Improved Performance of NbO x Resistive Switching Memory by In-Situ N Doping. NANOMATERIALS 2022; 12:nano12061029. [PMID: 35335842 PMCID: PMC8949618 DOI: 10.3390/nano12061029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/09/2022] [Accepted: 03/16/2022] [Indexed: 11/22/2022]
Abstract
Valence change memory (VCM) attracts numerous attention in memory applications, due to its high stability and low energy consumption. However, owing to the low on/off ratio of VCM, increasing the difficulty of information identification hinders the development of memory applications. We prepared N-doped NbOx:N films (thickness = approximately 15 nm) by pulsed laser deposition at 200 °C. N-doping significantly improved the on/off ratio, retention time, and stability of the Pt/NbOx:N/Pt devices, thus improving the stability of data storage. The Pt/NbOx:N/Pt devices also achieved lower and centralized switching voltage distribution. The improved performance was mainly attributed to the formation of oxygen vacancy (VO) + 2N clusters, which greatly reduced the ionic conductivity and total energy of the system, thus increasing the on/off ratio and stability. Moreover, because of the presence of Vo + 2N clusters, the conductive filaments grew in more localized directions, which led to a concentrated distribution of SET and RESET voltages. Thus, in situ N-doping is a novel and effective approach to optimize device performances for better information storage and logic circuit applications.
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Dehkordi AB, Badiei A. Insight into the activity of TiO 2@nitrogen-doped hollow carbon spheres supported on g-C 3N 4 for robust photocatalytic performance. CHEMOSPHERE 2022; 288:132392. [PMID: 34624354 DOI: 10.1016/j.chemosphere.2021.132392] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 09/12/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
Designing an advance nanostructure semiconductor is an efficient strategy to promote the charge separation and thus improve the photocatalytic activity. Herein, a relatively high recombination rate of electron-hole pairs and low specific surface area of g-C3N4 (GCN) were subjected to the surface deposition of the core shell nanoparticles composed of nitrogen doped hollow carbon spheres (N-HCSs) as the supporting scaffold and TiO2 nanoparticles as the photoactive layer. The ternary composites with different TiO2@N-HCS content were prepared through a simplified nanocasting method followed by the two consecutive hydrothermal process. The effects of nitrogen doping in carbon framework, and nanoparticles amount were evaluated on the photocatalytic ability through the photodegradation of tetracycline (TC) molecules under the visible light irradiation. At the optimum content of core shell nanoparticles (7 wt%), the solar-driven TC photocatalytic degradation for ternary composite was approximately 85%, which was much better (about three times) than that of the pure GCN. More interestingly, the experimental results revealed that doping of nitrogen atoms has a positive role on the charge separation and the resulting photocatalytic efficiency. The employed hollow carbon spheres here play three important roles: (1) providing a substrate to uniformly dispersion of TiO2 nanoparticles without any aggregation; (2) reducing the combination of charge carriers and improving the separation of photoinduced carriers; (3) formation of larger surface area and more active sites on the photocatalyst surface. Furthermore, the underlying photocatalytic degradation mechanism was introduced by the controlled experiments using photoluminescent and radical scavenger tests.
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Huang Z, Li Z, Zhu M, Wang G, Yu F, Wu M, Xu G, Dou SX, Liu HK, Wu C. Highly Stable Lithium/Sodium Metal Batteries with High Utilization Enabled by a Holey Two-Dimensional N-Doped TiNb 2O 7 Host. NANO LETTERS 2021; 21:10453-10461. [PMID: 34846156 DOI: 10.1021/acs.nanolett.1c03844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Lithium/sodium metal batteries have attracted enormous attention as promising candidates for high-energy storage devices. However, their practical applications are impeded by the growth of dendrites upon Li/Na plating. Here, we report that holey 2D N-doped TiNb2O7 (N-TNO) nanosheets with high electroactive surface area and large amounts of lithiophilic/sodiophilic sites can effectively regulate Li/Na deposition as an interfacial layer, leading to an excellent cycling stability. The N-TNO interfacial layer enables the Li||Li symmetric cell to sustain stable electrodeposition over 1000 h as well as the Na||Na cell to stably cycle for 2400 h at 1 mA cm-2 and 3 mA h cm-2 with a depth of discharge as high as 50%. The full cells of the Li/Na anodes based on the N-TNO layer paired with the LiFePO4 and NaTi2(PO4)3 cathodes, respectively, show a very stable cycling over 1000 cycles at a negative-to-positive electrode capacity (N/P) ratio up to 3.
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Li C, Gu M, Gao M, Liu K, Zhao X, Cao N, Feng J, Ren Y, Wei T, Zhang M. N-doping TiO 2 hollow microspheres with abundant oxygen vacancies for highly photocatalytic nitrogen fixation. J Colloid Interface Sci 2021; 609:341-352. [PMID: 34896834 DOI: 10.1016/j.jcis.2021.11.180] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/24/2021] [Accepted: 11/28/2021] [Indexed: 12/16/2022]
Abstract
Photocatalytic fixation of nitrogen to ammonia (NH3) is a green but low-efficiency technology due to the high recombination of photo-generated carriers and poor light absorption of photocatalysts. Generally, the adsorption capacity for N2 and the band position of TiO2 are responsible for bandgap, light-adsorption, and the separation of photocarriers. Therefore, they play crucial roles to improve catalytic activity. Herein, N-doping TiO2 hollow microspheres (NTO-0.5) with oxygen vacancies were synthesized via a hydrothermal method using phenolic resin microsphere as a template. The obtained NTO-0.5 achieves an impressive ammonia yield of 80.09 μmol gcat-1h-1. Oxygen vacancies of NTO-0.5 were confirmed by ESR, Raman, XPS, Zeta potential, and H2O2 treatment for reducing oxygen vacancies. The ammonia yield of NTO-0.5 decreases to 34.78 μmol gcat-1h-1 after reducing oxygen vacancies by H2O2 treatment, which demonstrates the importance of oxygen vacancies. The oxygen vacancies narrow the bandgap from 3.18 eV to 2.83 eV and impede the recombination of photo-generated carriers. The hollow microspheres structure is conducive to light absorption and utilization. Therefore, the synergistic effect between the oxygen vacancies and the hollow microspheres structure boosts the efficiency of photocatalytic nitrogen fixation. After four cycles, the ammonia production yield still maintains at 76.52 μmol gcat-1h-1, meaning high stability. This work provides a new insight into the construction of catalysts with oxygen vacancies to enhance photocatalytic nitrogen fixation performance.
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Wang G, Xu X, Kou X, Liu X, Dong X, Ma H, Wang D. N-Doping of Graphene Aerogel as a Multifunctional Air Cathode for Microbial Fuel Cells. ACS APPLIED MATERIALS & INTERFACES 2021; 13:51312-51320. [PMID: 34672529 DOI: 10.1021/acsami.1c12605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
One of the main challenges faced by microbial fuel cells (MFCs) generating voltage is how to facilitate the oxygen reduction reaction (ORR) process using a specifically designed air cathode, especially by optimizing a three-phase catalytic interface and enhanced O2 diffusion on it. Herein, a three-dimensional porous N-doped graphene aerogel (NGA) is polymerized onto a steel mesh (SM) to construct a simple structure of an air cathode (NGA-x/SM) via hydrothermal synthesis and subsequent freeze-drying treatment; more specifically, NGA was simultaneously used as an efficient ORR catalyst layer and breathable gas diffusion layer to improve the performance of MFCs. In this system, the NGA-5/SM (with a precursor concentration of x = 5.0 mg mL-1) makes itself a perfect candidate to be used as an air cathode. Characterization parameters reveal that sub-micrometer micropores, defective multilayer structures, and the highest proportion of pyridinic-N (48.1%) exist in NGA-5/SM. Furthermore, electrochemical measurements demonstrate that it has an oxygen reduction peak potential of 0.63 V, a Tafel slope of 187 mV dec-1, and closest 4e- transfer pathway (n = 3.2-3.5). These data prove that a three-phase boundary can naturally form in NGA-5/SM, where the ORR occurs. More importantly, this work provides a proof of concept that a Pt-free air cathode could be prepared with high-efficiency NGA by a two-step preparation method to achieve a MFC maximum power density of 1593 mW m-2.
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Wang D, Zhou A, Yao Z, Xia X, Zhang Y. Confined Polysulfides in N-Doped 3D-CNTs Network for High Performance Lithium-Sulfur Batteries. MATERIALS 2021; 14:ma14206131. [PMID: 34683724 PMCID: PMC8537132 DOI: 10.3390/ma14206131] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/08/2021] [Accepted: 10/11/2021] [Indexed: 11/16/2022]
Abstract
Improving the utilization efficiency of active materials and suppressing the dissolution of lithium polysulfides into the electrolyte are very critical for development of high-performance lithium-sulfur batteries. Herein, a novel strategy is proposed to construct a three-dimensional (3D) N-doped carbon nanotubes (CNTs) networks to support lithium polysulfides (3D-NCNT-Li2S6) as a binder-free cathode for high-performance lithium-sulfur batteries. The 3D N-doped CNTs networks not only provide a conductive porous 3D architecture for facilitating fast ion and electron transport but also create void spaces and porous channels for accommodating active sulfur. In addition, lithium polysulfides can be effectively confined among the networks through the chemical bond between Li and N. Owing to the synergetic effect of the physical and chemical confinement for the polysulfides dissolution, the 3D-NCNT-Li2S6 cathodes exhibit enhanced charge capacity and cyclic stability with lower polarization and faster redox reaction kinetics. With an initial discharge capacity of 924.8 mAh g-1 at 1 C, the discharge capacity can still maintain 525.1 mAh g-1 after 200 cycles, which is better than that of its counterparts.
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Xu Y, Li G, Jing Y, Zhang H, Wang X, Lu Y, Wu J, Lan Z. n-type absorber by Cd 2+ doping achieves high-performance carbon-based CsPbIBr 2 perovskite solar cells. J Colloid Interface Sci 2021; 608:40-47. [PMID: 34624764 DOI: 10.1016/j.jcis.2021.09.117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/11/2021] [Accepted: 09/20/2021] [Indexed: 10/20/2022]
Abstract
High efficiency and stability have long been the key issues faced by perovskite solar cells (PSCs). It is found that the CsPbIBr2 all-inorganic perovskite has a suitable band gap and satisfactory stability, so it has attracted much attention. However, the many defects in the CsPbIBr2 film are one of the main problems hindering the improvement of power conversion efficiency (PCE) of the CsPbIBr2 PSCs. The substitution of trace impurities is undoubtedly a simple, cost-effective and efficient strategy. In this work, an appropriate amount of Cd2+ (1.0% mol of Pb2+) is added into the CsPbIBr2 precursor solution to fabricate high quality CsPbIBr2 film with improved crystallinity, reduced trap density, suppressed photo-generated carrier recombination, displayed n-type doping and optimized energy level alignment. The corresponding carbon-based all-inorganic Cd2+-doped CsPbIBr2 PSCs achieve a maximum PCE of 10.63% with a high open circuit voltage (VOC) of 1.324 V, which are much higher than those of the control one with a PCE of 8.48% and an VOC of 1.235 V. The unencapsulated device can still retain more than 92% of the initial PCE when stored at ambient atmosphere (25 °C, relative humidity about 30%) for 40 days.
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Nitrogen-Doped Carbon Aerogels Derived from Starch Biomass with Improved Electrochemical Properties for Li-Ion Batteries. Int J Mol Sci 2021; 22:ijms22189918. [PMID: 34576084 PMCID: PMC8468214 DOI: 10.3390/ijms22189918] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/10/2021] [Accepted: 09/12/2021] [Indexed: 11/16/2022] Open
Abstract
Among all advanced anode materials, graphite is regarded as leading and still-unrivaled. However, in the modern world, graphite-based anodes cannot fully satisfy the customers because of its insufficient value of specific capacity. Other limitations are being nonrenewable, restricted natural graphite resources, or harsh conditions required for artificial graphite production. All things considered, many efforts have been made in the investigation of novel carbonaceous materials with desired properties produced from natural, renewable resources via facile, low-cost, and environmentally friendly methods. In this work, we obtained N-doped, starch-based carbon aerogels using melamine and N2 pyrolysis as the source of nitrogen. The materials were characterized by X-ray powder diffraction, elemental analysis, X-ray photoelectron spectroscopy, galvanostatic charge-discharge tests, cyclic voltammetry, and electrochemical impedance spectroscopy. Depending on the doping method and the nitrogen amount, synthesized samples achieved different electrochemical behavior. N-doped, bioderived carbons exhibit far better electrochemical properties in comparison with pristine ones. Materials with the optimal amount of nitrogen (such as MCAGPS-N8.0%-carbon aerogel made from potato starch modified with melamine and CAGPS-N1.2%-carbon aerogel made from potato starch modified by N2 pyrolysis) are also competitive to graphite, especially for high-performance battery applications. N-doping can enhance the efficiency of Li-ion cells mostly by inducing more defects in the carbon matrix, improving the binding ability of Li+ and charge-transfer process.
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Preparation of Multifunctional N-Doped Carbon Quantum Dots from Citrus clementina Peel: Investigating Targeted Pharmacological Activities and the Potential Application for Fe 3+ Sensing. Pharmaceuticals (Basel) 2021; 14:ph14090857. [PMID: 34577557 PMCID: PMC8465261 DOI: 10.3390/ph14090857] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 08/21/2021] [Accepted: 08/24/2021] [Indexed: 01/03/2023] Open
Abstract
Carbon quantum dots (CQDs) have recently emerged as innovative theranostic nanomaterials, enabling fast and effective diagnosis and treatment. In this study, a facile hydrothermal approach for N-doped biomass-derived CQDs preparation from Citrus clementina peel and amino acids glycine (Gly) and arginine (Arg) has been presented. The gradual increase in the N-dopant (amino acids) nitrogen content increased the quantum yield of synthesized CQDs. The prepared CQDs exhibited good biocompatibility, stability in aqueous, and high ionic strength media, similar optical properties, while differences were observed regarding the structural and chemical diversity, and biological and antioxidant activity. The antiproliferative effect of CQD@Gly against pancreatic cancer cell lines (CFPAC-1) was observed. At the same time, CQD@Arg has demonstrated the highest quantum yield and antioxidant activity by DPPH scavenging radical method of 81.39 ± 0.39% and has been further used for the ion sensing and cellular imaging of cancer cells. The obtained results have demonstrated selective response toward Fe3+ detection, with linear response ranging from 7.0 µmol dm−3 to 50.0 µmol dm−3 with R2 = 0.9931 and limit of detection (LOD) of 4.57 ± 0.27 µmol dm−3. This research could be a good example of sustainable biomass waste utilization with potential for biomedical analysis and ion sensing applications.
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Liao L, Zhang A, Zheng K, Liu R, Cheng Y, Wang L, Li A, Liu J. Fabrication of Cobaltous Sulfide Nanoparticle-Modified 3D MXene/Carbon Foam Hybrid Aerogels for All-Solid-State Supercapacitors. ACS APPLIED MATERIALS & INTERFACES 2021; 13:28222-28230. [PMID: 34105949 DOI: 10.1021/acsami.1c05904] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
MXene is a neoteric type of bidimensional (2D) transition metal carbide/nitride with broad application prospects, in particular with electrochemical energy storage. The electrochemical performance of MXene is unsatisfactory because it is easy to stack resulting in the difficulty of electrolyte penetration and ion transport. In this study, the cobaltous sulfide-modified 3D MXene/N-doped carbon foam (CoS@MXene/CF) hybrid aerogel is projected and manufactured via simple in situ growth and thermal annealing strategies. The capacitance of the as-fabricated 300-CMC-31:1 electrode material reaches 250 F g-1 (1 A g-1), which is obviously higher than those of MXene, CoS@CF, 400-CMC-31:1, 300-CMC-10:1, 300-CMC-50:1, CF, and MXene/CF electrode materials. Moreover, it can hold 97.5% of the original capacitance after 10,000 cycles and the internal resistance (Rs) is only 0.50 Ω. A green bulb can be lit by two all-solid asymmetric supercapacitors installed in series. The prepared CoS@MXene/CF hybrid aerogel exhibits promising potential for practical application in energy storage areas.
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Guo H, Li W, Chen K, Yue M, Huang Y, Liu Y, Shao H, Chen C, Wang C, Wang Y. Strategic Structure Tuning of Yolk-Shell Microcages for Efficient Nitrogen Fixation. CHEMSUSCHEM 2021; 14:2521-2528. [PMID: 33830646 DOI: 10.1002/cssc.202100502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/03/2021] [Indexed: 06/12/2023]
Abstract
The electrocatalytic nitrogen reduction reaction (ENRR) under ambient conditions is considered as a promising process to produce ammonia. Towards highly efficient catalysts, here an optimized one-step pyrolysis strategy was tailored to design yolk-shell microcages (YS Co@C/BLCNTs), consisting of Co nanocrystals encapsulated in N-doped carbon framework and bridged by bamboo-like carbon nanotubes (BLCNTs). The cavity created between yolk and shell not only served as a "micro-bag" to store the reactant N2 and enhance its dissolution, but also induced a "cage effect" to confine the diffusion of reaction intermediate, hence making the reaction proceed in the direction of producing NH3 . This catalyst displayed excellent catalytic activities for ENRR: a high NH3 yield of 12.87 μg mgcat -1 h-1 at a high faradaic efficiency of 20.7 % at -0.45 V (vs. reversible hydrogen electrode, RHE). After 5 cycles of consecutive ENRR process, the NH3 yield rate was 11.29 μg mgcat -1 h-1 , indicating the excellent electrocatalytic stability. These results provide a structural engineering for ENRR catalyst with doped N, cooperating with non-precious metal to activate the inert triple bond of N2 and achieve NH3 fixation.
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Hu B, Li X, Busser W, Schmidt S, Xia W, Li G, Li X, Peng B. The Role of Nitroge n-doping in the Catalytic Transfer Hydrogenation of Phenol to Cyclohexanone with Formic Acid over Pd supported on Carbon Nanotubes. Chemistry 2021; 27:10948-10956. [PMID: 33998733 PMCID: PMC8361974 DOI: 10.1002/chem.202100981] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Indexed: 12/14/2022]
Abstract
Highly selective one‐step hydrogenation of phenol to cyclohexanone, an important intermediate in the production of nylon 6 and nylon 66, is desirable but remains a challenge. Pd nanoparticles supported on nitrogen‐ and oxygen‐functionalized carbon nanotubes (NCNTs, OCNTs) were prepared, characterized, and applied in the hydrogenation of phenol to cyclohexanone to study the effect of N‐doping. Almost full conversion of phenol with high selectivity to cyclohexanone was achieved over Pd/NCNT under mild reaction conditions using either H2 or formic acid (FA) as a hydrogen source. The effects of reaction temperature and FA/phenol ratio and the reusability were investigated. Separate FA decomposition experiments without and with the addition of phenol were performed to investigate the reaction mechanism, especially the deactivation behavior. Deactivation was observed for both catalysts during the FA decomposition, while only Pd/OCNT rather than Pd/NCNT was deactivated in the transfer hydrogenation with FA and the FA decomposition in the presence of phenol, indicating the unique role of N‐doping. Therefore, we assume that deactivation is caused by the strongly bound formates on the active Pd sites, suppressing further FA decomposition and/or transfer hydrogenation on Pd. The nonplanar adsorption of phenol on NCNTs via weak O−H⋅⋅⋅N interactions enables the occurrence of the subsequent hydrogenation by adsorbed formate on Pd.
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Zhang F, Ji S, Wang H, Liang H, Wang X, Wang R. Implanting Cobalt Atom Clusters within Nitrogen-Doped Carbon Network as Highly Stable Cathode for Lithium-Sulfur Batteries. SMALL METHODS 2021; 5:e2100066. [PMID: 34927900 DOI: 10.1002/smtd.202100066] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/15/2021] [Indexed: 06/14/2023]
Abstract
Realization of highly efficient sulfur electrochemistry, as well as the high capacity of lithium-sulfur (Li-S) batteries, can be achieved by the scientific construction of electrode host materials. In this study, using molten NaCl, a 3D porous nitrogen-doped carbon with uniformly embedded Co atom clusters (Co/PNC) is developed by pyrolyzing the precursors with NaCl at high temperatures. In the composite structure, a network carbon skeleton containing hierarchical pores acts as an advanced matrix for sulfur electrodes, and the doping of N and Co is subject to inhibit the shuttle of long-chain lithium polysulfides through chemical adsorption. The Co/PNC, with the optimized amount of Co, delivers an initial specific capacity of 1105.4 mAh g-1 at 0.2 C with a capacity drop of only 0.064% after the cell is charged and discharged for 300 cycles at 1 C, revealing its potential in promoting the large-scale application of Li-S batteries.
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Huang KX, Hua J, Chang GG, Li Z, Tian G, Chen MJ, Li JX, Ke SC, Yang XY, Chen B. Confined Thermolysis for Oriented N-Doped Carbon Supported Pd toward Stable Catalytic and Energy Storage Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2002811. [PMID: 32734686 DOI: 10.1002/smll.202002811] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 05/24/2020] [Indexed: 06/11/2023]
Abstract
Carbon-based nanomaterials have been widely utilized in catalysis and energy-related fields due to their fascinating properties. However, the controllable synthesis of porous carbon with refined morphology is still a formidable challenge due to inevitable aggregation/fusion of resulted carbon particles during the high-temperature synthetic process. Herein, a hierarchically oriented carbon-structured (fiber-like) composite is fabricated by simultaneously taking advantage of a confined pyrolysis strategy and disparate bond environments within metal-organic frameworks (MOFs). In the resultant composite, the oriented carbon provides a fast mass (molecule/ion/electron) transfer efficiency; the doping-N atoms can anchor or act as active sites; the mesoporous SiO2 (mSiO2 ) shell not only effectively prevents the derived carbon or active metal nanoparticles (NPs) from aggregation or leaching, but also acts as a "polysulfide reservoir" in the Li-S batteries to suppress the "shuttle" effect. Benefiting from these advantages, the synthesized composite Pd@NDHPC@mSiO2 (NDHPC means N-doped hierarchically porous carbon) exhibits extremely high catalytic activity and stability toward the one-pot Knoevenagel condensation-hydrogenation reaction. Furthermore, the oriented NDHPC@mSiO2 manifests a boosted capacity and cycling stability in Li-S batteries compared to the counterpart that directly pyrolyzes without silica protection. This report provides an effective strategy of fabricating hierarchically oriented carbon composites for catalysis and energy storage applications.
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Xing P, Zhou F, Zhan S. Catalytic conversion of seawater to fuels: Eliminating N vacancies in g-C 3N 4 to promote photocatalytic hydrogen production. ENVIRONMENTAL RESEARCH 2021; 197:111167. [PMID: 33861976 DOI: 10.1016/j.envres.2021.111167] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/17/2021] [Accepted: 04/08/2021] [Indexed: 06/12/2023]
Abstract
The use of solar energy to decompose seawater and produce hydrogen is of great significance in solving the energy crisis. Numerous studies have shown that vacancies can significantly improve photocatalytic activity due to their electron-rich nature. However, our recent research has shown that materials with vacancies are not suitable for photocatalytic reactions in seawater. In this study, g-C3N4 with rich N vacancies was selected as the research object, and urea was used as the precursor; in this system, the N vacancies in g-C3N4 could be effectively reduced by the addition of ZIF-8 (ZCNQx). The activity of ZCNQ40 was 5.6 times higher than that of g-C3N4 in fresh seawater, but only 3.1 times higher in freshwater. Based on the analysis of the experimental results, we believe that g-C3N4 has a limiting relationship between H+ adsorption catalysis and H2 product desorption. In addition, seawater contains many heteroatoms that will also compete with proton (H+) reduction. The results of our study show that catalysts with vacancies are not necessarily suitable for catalytic reactions in seawater media. This research will stimulate new ideas for research into the conversion of solar energy to chemical energy in seawater media.
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Xu S, Tan L, Liu F, Cui Y, Wang C, Zhang R. Investigation of optical properties for N- and F-doped triangular shaped carbon molecules. J Mol Model 2021; 27:154. [PMID: 33954863 DOI: 10.1007/s00894-021-04758-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 04/18/2021] [Indexed: 10/21/2022]
Abstract
Optical properties of N- and F-doping triangular-shaped carbon molecules have been investigated in theory and experiment. The theoretical results showed that carbon molecules with impurity F and Cl have the same characters with pure carbon. Doping N into pure carbon molecule would change the optical rotation at 589 nm. For doping N replacing hydrogen atom structures (N-doping 1 and N-doping 2 molecules), the absorption spectra of them are similar to pure carbon molecule. However, for molecules with impurity N atom in benzene ring (N-doping 3 and N-doping 4 molecules), the peaks of wavelength of absorption spectra shift to long wavelength compared to that of pure carbon molecule. Moreover, the delocalization of molecular orbital (MO) is different from pure carbon molecule, which is caused by the impurity N changing the electrons distribution of benzene ring. We have calculated 3 without H and 4 without H molecules which are removing hydrogen atom in nitrogen atom from N-doping 3 and 4. 3 without H and 4 without H molecules have similar optical properties with pure carbon molecule. The results testified that the impurity N and F would not change the optical properties of carbon molecule if impurity did not change the delocalization of all benzene rings. Optical properties of nitrogen- and fluorine-doping carbon molecules investigating in theory and experiment.
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Remote Doping Effects of Indium-Gallium-Zinc Oxide Thin-Film Transistors by Silane-Based Self-Assembled Monolayers. MICROMACHINES 2021; 12:mi12050481. [PMID: 33922430 PMCID: PMC8145249 DOI: 10.3390/mi12050481] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/13/2021] [Accepted: 04/22/2021] [Indexed: 11/16/2022]
Abstract
Oxide thin-film transistors (TFTs), including indium–gallium–zinc oxide (IGZO) TFTs, have been widely investigated because of their excellent properties, such as compatibility with flexible substrates, high carrier mobility, and easy-to-fabricate TFT processes. However, to increase the use of oxide semiconductors in electronic products, an effective doping method that can control the electrical characteristics of oxide TFTs is required. Here, we comprehensively investigate the effect of silane-based self-assembled monolayer (SAM) doping on IGZO TFTs. Instead of a complex doping process, the electrical performance can be enhanced by anchoring silane-based SAMs on the IGZO surface. Furthermore, differences in the doping effect based on the structure of SAMs were analyzed; the analysis offers a systematic guideline for effective electrical characteristic control in IGZO TFTs.
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Huang J, Dou L, Li J, Zhong J, Li M, Wang T. Excellent visible light responsive photocatalytic behavior of N-doped TiO 2 toward decontamination of organic pollutants. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123857. [PMID: 33264933 DOI: 10.1016/j.jhazmat.2020.123857] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 08/15/2020] [Accepted: 08/17/2020] [Indexed: 06/12/2023]
Abstract
In this work, N-doped TiO2 (N-TiO2) with ample and tunable OVs was successfully synthesized, deriving from facile hydrothermal method and baked in the NH3 atmosphere. N-doping boosts the amount of surface hydroxyl and superoxide (O2-) of TiO2, demonstrated by XPS and nitroblue tetrazolium (NBT)-O2- quantitative reaction. Rich and tunable OVs were confirmed by low temperature electron spin resonance (ESR) results, demonstrating that doping of N into TiO2 can definitely construct higher OVs than the reference TiO2. Surface photovoltage spectrum (SPS) test, fluorescence experiments and electrochemical measurements all display that N-TiO2 photocatalysts with OVs have a higher severance efficiency of photogenerated e-/h+ pairs than the pristine TiO2. Photocatalytic evaluation results exhibit that N-TiO2 photocatalysts demonstrate better performance than the reference TiO2 toward decontamination of rhodamine B and tetracycline. TiO2 treated in ammonia atmosphere for 1 h shows the highest photocatalytic property. The visible light responsive catalytic behavior of TiO2 treated in ammonia atmosphere for 1 h is much higher than that of commercial TiO2 (P25) and the pristine TiO2, separately. The ameliorated visible light behavior of N-TiO2 photocatalysts is attributable to rich oxygen vacancies produced through introducing N into TiO2 and the boosted severance of photoactivated e-/h+.
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