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[Display omitted] Organic thermoelectrics (TEs) based on carbon nanotubes (CNTs) have attracted much attention with their inherent advantages, such as, earth-abundant elements, broad electronic tunability, and excellent mechanical compliance. However, the inferior TE performance and doping stability of n-type CNTs to those of p-type CNTs have been bottlenecks to establish CNT-based next-generation TEs. Herein, we report a hybrid n-doping method that improves the n-type TE performance and long-term air-stability of water-processable single-walled CNT (SWCNT) and carboxymethyl cellulose (CMC) composite. The hybrid n-doping process with polyethyleneimine (PEI) n-dopant contains primary addition and secondary immersion doping, which causes a simultaneous increase in electrical conductivity and Seebeck coefficient through efficient n-doping and surface energy filtering effect, respectively. Furthermore, the hybrid-doped films exhibit superior long-term stability by inhibiting the oxidation of SWCNT/CMC at nanoscale, which allows to ensure the initial power factor even after storing in ambient for a month. Finally, we successfully demonstrated hybrid-doped SWCNT/CMC-based TEGs with long-term stable output characteristics. This work can offer insights to develop efficient and air-stable n-type organic TE materials and devices. [ABSTRACT FROM AUTHOR]

Phase-change random access memory (PcRAM) faces significant challenges due to the inherent instability of amorphous Ge2Sb2Te5 (GST). While doping has emerged as an effective method for amorphous stabilization, understanding the precise mechanisms of structural modification and their impact on material stability remains a critical challenge. This study provides a comprehensive investigation of elastic strain and stress in crystalline lattices induced by various dopants (C, N, and Al) through systematic measurements of film thickness changes during crystallization. Through detailed analysis of cross-sectional electron microscopy data and theoretical calculations, we reveal distinct behavior patterns between interstitial and substitutional dopants. Interstitial dopants (C and N) generate substantial elastic strain energy (~9 J/g) due to their smaller atomic radii (0.07–0.08 nm) and ability to occupy spaces between lattice sites. In contrast, substitutional dopants (Al) produce lower strain energy (~5 J/g) due to their similar atomic radius (0.14 nm) to host atoms. We demonstrate that N doping achieves higher elastic strain energy compared to C doping, attributed to its preferential formation of Ge-N bonds and resulting lattice distortions. The correlation between dopant properties, structural features, and induced strain energy provides quantitative insights for optimizing dopant selection. These findings establish a fundamental framework for understanding dopant-induced thermodynamic stabilization in GST materials, offering practical guidelines for enhancing the reliability and performance of next-generation PcRAM devices. [ABSTRACT FROM AUTHOR]

Triarylamines are frequently employed as electron donor functional groups in a variety of organic electronic materials. We herein report the synthesis and in‐depth characterisation of aza‐analogues of fully bridged triarylamines, consisting of 5‐, 6‐ and 7‐membered rings. The impact of nitrogen doping and π‐extension on the structural, electronic and optical‐properties of these contorted heteroaromatic PAHs is thoroughly investigated and paves the way for an improved understanding of the structure‐property relationships. [ABSTRACT FROM AUTHOR]

Highly efficient photocatalysts have been developed for the degradation of contaminated water under visible light. In this study, N-doped TiO2 (N-TiO2) and metal-free graphitic carbon nitride (g-C3N4) composites with various Ti/C molar ratios were prepared with the simple mixing-calcining method. The samples were characterized by X-ray diffraction, scanning electron microscopy, ultraviolet–visible diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The photocatalytic activity of N-TiO2/g-C3N4 in the degradation of Rhodamine B (RhB) was investigated, and the electrochemical method was used to determine the origin of the enhanced photoactivity of N-TiO2/g-C3N4. The results showed that N-TiO2 nanoparticles were dispersed on the surface of g-C3N4 and formed a stable heterojunction structure with g-C3N4. The heterojunction between the two semiconductors could effectively prevent the recombination of photogenerated electrons and holes and improve the photocatalytic efficiency of the photocatalyst under visible light irradiation. The photocatalyst exhibited high stability, and the RhB degradation rate was still higher than 82.3% after five cycles.

In this research, the different characteristics of MoSe2 and N‐doped MoSe2 monolayers were studied using density functional theory calculations. The negative cohesive energy (−5.216 eV for MoSe2 and −5.333 eV for N‐MoSe2) verified their energetical stability. The variation of structural, electronic, and optical properties of MoSe2 and N‐MoSe2 via adsorption of PH3, C2N2, and HN3 gases are studied. The N‐doping results in a stronger adsorbent‐gas interaction, resulting in maximum adsorption energy of −0.036, −0.033, and −0.198 eV for the selected gases. The MoSe2 and N‐MoSe2 monolayers showed a direct band gap of 1.48 eV and 1.09 eV, respectively. However, upon interaction with the gases, a notable shift in the band gap of both adsorbents is observed. N‐MoSe2 showed semiconductor‐to‐conductor transition via C2N2 and HN3 adsorption. The sensitivity of MoSe2 for the selected gases has improved remarkably via N‐doping. Also, HN3 gas can be easily detected by the N‐MoSe2 monolayer due to the greater changes in work function (0.45 eV). The absorption coefficient of both adsorbents is over 105 cm−1 order in the UV region, which suffers a mild peak shifting due to gas adsorption. This study suggests that N‐MoSe2 can be a potential candidate for selected gas sensing. [ABSTRACT FROM AUTHOR]

Efficient conversion of abundant biomass into high-value chemicals is crucial for sustainable chemical production. Herein, we report the design and synthesis of a Pd nanoparticles (NPs)-embedded N-doped carbon nitride (Pd@NCN) nanocomposite for the photocatalytic transformation of biomass-derived compounds. N-doping of carbon nitride using DMF significantly enhanced visible light absorption, as evidenced by DRUV spectroscopy, making it a suitable photocatalyst for blue LED-driven reactions. Subsequent decoration with Pd NPs remarkably improved the catalyst's performance. UPS measurements revealed that Pd NPs, with their lower Fermi level and higher work function compared to the photoactive support, act as efficient electron acceptors, promoting charge separation and improving the catalytic activity. This was corroborated by PL, TCSPC, and EIS studies. Photogenerated electrons on the Pd NPs surface-activated hydrogen, enabling the hydrogenation of biomass derivatives at room temperature. Concurrently, photogenerated holes were consumed by IPA via O–H and C–H, leading to acetone formation. The optimized 1% Pd@N0.75CN catalyst exhibited exceptional activity in the hydrogenation of vanillin (VAN), achieving 79.6% conversion and 94.4% selectivity to vanillyl alcohol (VOL) within an hour. Moreover, reaction selectivity could be tuned by adjusting Pd NPs loading and reaction time, leading to complete VAN conversion and excellent selectivity (∼99%) to 2-methoxy-4-methylphenol (MMP) using 2% Pd@N0.75CN in 4.5 h. Comprehensive characterization and mechanistic studies provided insights into the structure–activity relationship, paving the way for the development of advanced NPs-based photocatalysts for challenging biomass valorization at ambient conditions. [ABSTRACT FROM AUTHOR]

Developing n‐doped conjugated polymers (CPs) with good air stability remains a significant obstacle to the advancement of organic thermoelectrics. In this study, three CPs (designated PmQ2F, PsQ4F, and PsQ6F) containing an oxindole‐terminated quinoidal unit are synthesized. To obtain an isomeric purity quinoidal unit and tune the LUMO (lowest unoccupied molecular orbital) energies of the CPs, fluoride (F) atoms on the monomers are strategically installed. Compared to a polymer with isomeric quinoidal units (PmQ2F), polymers with an isomerically pure quinoidal unit (PsQ4F and PsQ6F) exhibited higher electron mobilities owing to their more‐ordered molecular packing structures. After n‐doping, PsQ4F and PsQ6F show higher electrical conductivities than PmQ2F. Moreover, the former demonstrated excellent air stability for over 2 months, which can be attributed to the synergistic effects of the quinoidal structure and the reduced LUMO energy. The work offers a novel molecular design strategy that can be expected to advance the development of n‐type CPs for air‐stable organic thermoelectrics. [ABSTRACT FROM AUTHOR]

The development of n‐type organic thermoelectric materials, especially π‐conjugated small molecules, lags far behind their p‐type counterparts, due primarily to the scarcity of efficient electron‐transporting molecules and the typically low electron affinities of n‐type conjugated molecules that leads to inefficient n‐doping. Herein, the n‐doping of two functionalized (carbonyl vs dicyanovinylene) indenofluorene‐based conjugated small molecules, 2,8‐bis(5‐(2‐octyldodecyl)thien‐2‐yl)indeno[1,2‐b]fluorene‐6,12‐dione (TIFDKT) and 2,2′‐(2,8‐bis(3‐alkylthiophen‐2‐yl)indeno[1,2‐b]fluorene‐6,12‐diylidene)dimalononitrile (TIFDMT) are demonstrated, with n‐type dopant N‐DMBI. While TIFDKT shows decent miscibility with N‐DMBI, it can be hardly n‐doped owing to its insufficiently low LUMO. On the other hand, TIFDMT, despite a poorer miscibility with N‐DMBI, can be efficiently n‐doped, reaching a respectable electrical conductivity of 0.16 S cm−1. Electron paramagnetic resonance measurements confirm the efficient n‐doping of TIFDMT. Based on density functional theory (DFT) calculations, the LUMO frontier orbital energy of TIFDMT is much lower, and its wave function is more delocalized compared to TIFDKT. Additionally, the polarons are more delocalized in the n‐doped TIFDMT. Remarkably, as indicated by the grazing‐incidence wide‐angle X‐ray scattering (GIWAXS), the molecular order for TIFDMT thin‐film is enhanced by n‐doping, leading to more favorable packing with edge‐on orientation and shorter π‐π stacking distances (from 3.61 to 3.36 Å). This induces more efficient charge transport in the doped state. Upon optimization, a decent thermoelectric power factor of 0.25 µWm−1K−2 is achieved for n‐doped TIFDMT. This work reveals the effect of carbonyl vs dicyanovinylene on the n‐doping efficiency, microstructure evolution upon doping and thermoelectric performance, offering a stepping stone for the future design of efficient n‐type thermoelectric molecules. [ABSTRACT FROM AUTHOR]

Hydrogen has garnered considerable attention as a promising energy source for addressing contemporary environmental degradation and energy scarcity challenges. Electrocatalytic water splitting for hydrogen production has emerged as an environmentally friendly and versatile method, offering high purity. However, the development of cost-effective electrocatalytic catalysts using abundant and inexpensive materials is crucial. In this study, we successfully synthesized nitrogen-doped Co6Mo6C supported on nitrogen-doped graphene (N-Co6Mo6C/NC). The catalyst exhibited high performance and durability in alkaline electrolytes (1.0 M KOH) for hydrogen evolution, showcasing an overpotential of 185 mV at a current density of 100 mA cm−2 and a Tafel slope of 80 mV dec−1. These findings present a novel avenue for the fabrication of efficient bimetallic carbide catalysts. [ABSTRACT FROM AUTHOR]

Selective catalytic NH 3 -to-N 2 oxidation (NH 3 -SCO) is highly promising for abating NH 3 emissions slipped from stationary flue gas after-treatment devices. Its practical application, however, is limited by the non-availability of low-cost catalysts with high activity and N 2 selectivity. Here, using defect-rich nitrogen-doped carbon nanotubes (NCNT-AW) as the support, we developed a highly active and durable copper-based NH 3 -SCO catalyst with a high abundance of cuprous (Cu+) sites. The obtained Cu/NCNT-AW catalyst demonstrated outstanding activity with a T 50 (i.e. the temperature to reach 50% NH 3 conversion) of 174°C in the NH 3 -SCO reaction, which outperformed not only the Cu catalyst supported on N-free O-functionalized CNTs (OCNTs) or NCNT with less surface defects, but also those most active Cu catalysts in open literature. Reaction kinetics measurements and temperature-programmed surface reactions using NH 3 as a probe molecule revealed that the NH 3 -SCO reaction on Cu/NCNT-AW follows an internal selective catalytic reaction (i -SCR) route involving nitric oxide (NO) as a key intermediate. According to mechanistic investigations by X-ray photoelectron spectroscopy, Raman spectroscopy, and X-ray absorption spectroscopy, the superior NH 3 -SCO performance of Cu/NCNT-AW originated from a synergy of surface defects and N-dopants. Specifically, surface defects promoted the anchoring of CuO nanoparticles on N-containing sites and, thereby, enabled efficient electron transfer from N to CuO, increasing significantly the fraction of SCR-active Cu+ sites in the catalyst. This study puts forward a new idea for manipulating and utilizing the interplay of defects and N-dopants on carbon surfaces to fabricate Cu+-rich Cu catalysts for efficient abatement of slip NH 3 emissions via selective oxidation. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Molybdenum disulfide (MoS2) is a promising electronic material owing to its excellent electrochemical features, high carrier mobility at room temperature, and widely tunable electronic properties. Here, through precursor engineering and post‐treatments to tailor their phase and doping, electronic characteristics of MoS2 are significantly modified. It is found that 2H semiconductor phase with nitrogen doping (N‐doping) in flexible gas sensors constructed with Ag electrodes exhibits the highest sensitivity of ≈2500% toward 10 ppm of NO2. This sensitivity is ≈17‐ and 417‐folds higher than that of 2H MoS2 without N‐doping, and mixed phases with metallic 1T and semiconductor 2H phase, respectively. Comprehensive experimental investigations reveal mechanisms underlying this record sensitivity, that is, the use of N‐doped 2H MoS2 sensors not only significantly suppresses dark current but also effectively enhances electron transfer to NO2 molecules. Moreover, density function theory calculations underpin the experimental results, confirming that N2H4 molecules from the precursor solution not only promote phase transition but also enable N‐doping during post‐treatments, thus boosting sensing capability. This work, for the first time, reveals the synergistic effect of phase modulation and N‐doping of MoS2, which can be readily used in other flexible electronic applications, advancing MoS2‐based electronics to a new stage.

Electrochemical CO2 reduction can convert CO2 into high-value-added products for special forms of energy storage and efficient carbon utilization for renewable electricity. To investigate the influence of biochar-Cu-based catalysts properties on electrochemical CO2 reduction performance, Cu is loaded onto rice husk-based biochar by impregnation method combined with pyrolysis and calcination in this study. The three synthesized biochar-Cu-based catalysts are tested for activity and electrochemical CO2 reduction performance in Flow Cell. The results show that biochar's properties, such as its high specific surface area, rich pore structure, and adjustable pore structure, provide sufficient sites for CO2 reduction. Urea can relatively increase the copper loading by 44 %, but it will also increase the clustering of copper. In the reduction performance test, the current density of char-Cu-700 is 2.08 times higher than that of char-Cu and 1.45 times higher than char-Cu-N at a reduction potential of -0.45 (V vs. RHE). The current density enhancement of the catalyst loaded on biochar with Cu particle size of 10 nm is about 50 % higher than that of the catalyst with a particle size of 20 nm. It indicates that the smaller the particle size of Cu at the nanoscale, the lower the average coordination of surface atoms and the greater the catalyst's reactivity. This study provides novel ideas for synthesizing biochar-Cu-based catalysts, lays part of the theoretical foundation for using biochar-Cu-based catalysts for electrochemical CO2 reduction, and provides experimental support for optimizing the catalyst structure.

Lightweight and semi‐transparent organic solar cells (ST‐OSCs) offer bright promise for applications such as building integrated photovoltaics. Diluting donor content in bulk‐heterojunction active layers to allow greater visible light transmittance (AVT) effectively enhances device transparency, yet the ineluctable compromise of the donor‐phase continuity is challenging for efficient charge transport. Herein, a trace amount of n‐type N‐DMBI dopant is incorporated, which facilitates the donor:acceptor (D:A) de‐mixing by strengthening both acceptor polarity and D/A crystallization. With the diminution of component inter‐mixing, the limited number of donors increasingly self‐aggregate to establish the more continuous phases. For the benchmark PM6:Y6‐based ST‐OSCs, when the donor content is reduced from regular 45 to optimal 30 wt.%, the device AVT is remarkably raised by more than a quarter, accompanied by a marginal drop in power conversion efficiency from 13.89% to 13.03%. This study reveals that by decreasing the donor content to <30 wt%, acceptor excitons induced by Förster resonance energy transfer are prone to severe radiative recombination. This is nonetheless mitigated by dopant inclusion within the acceptor phase by providing extra energy offset and prolonging charge transfer state lifetime to assist exciton dissociation. [ABSTRACT FROM AUTHOR]

A new approach to control the n‐doping reaction of organic semiconductors is reported using surface‐functionalized gold nanoparticles (f‐AuNPs) with alkylthiols acting as the catalyst only upon mild thermal activation. To demonstrate the versatility of this methodology, the reaction of the n‐type dopant precursor N‐DMBI‐H with several molecular and polymeric semiconductors at different temperatures with/without f‐AuNPs, vis‐à‐vis the unfunctionalized catalyst AuNPs, was investigated by spectroscopic, morphological, charge transport, and kinetic measurements as well as, computationally, the thermodynamic of catalyst activation. The combined experimental and theoretical data demonstrate that while f‐AuNPs is inactive at room temperature both in solution and in the solid state, catalyst activation occurs rapidly at mild temperatures (~70 °C) and the doping reaction completes in few seconds affording large electrical conductivities (~10–140 S cm−1). The implementation of this methodology enables the use of semiconductor+dopant+catalyst solutions and will broaden the use of the corresponding n‐doped films in opto‐electronic devices such as thin‐film transistors, electrochemical transistors, solar cells, and thermoelectrics well as guide the design of new catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • A green PMS activation catalyst (N -CG) was fabricated via impregnation calcination. • N -CG exhibited excellent degradation efficiency toward benzo(a)pyrene polluted soil. • Melamine increased the ratio of graphitic N and Pyridine N during thermal annealing. • The mechanism of N -doping in coal gangue for PMS activation was well proposed. Efficient degradation of organic pollutants in complex media via advanced oxidation processes (AOPs) is still critical and challenging. Herein, nitrogen (N)-doped coal gangue (CG) catalysts (N -CG) with economic competitiveness and environmental friendliness were successfully synthesized to activate peroxymonosulfate (PMS), exhibiting ultrafast degradation performance toward benzo(a)pyrene (BaP) with 100.00 % and 93.21 % in contaminated solution and soil under optimized condition, respectively. In addition, 0.4 N -CG possessed excellent reusability toward BaP degradation with over 80.00 % after five cycles. However, BaP removal efficiency was significantly affected by some co-existing anions (HCO 3 − and SO 4 2−) and humic acid (HA) in solution and soil, as well as inhibited under alkaline conditions, especially pH ≥ 9. According to the characterizations, N -doping could promote the generation of pyridinic N and graphitic N in N -CG via high-temperature calcination, which was conducive to produce hydroxyl radical (•OH), sulfate radical (SO 4 •−), superoxide radical (•O 2 −) and single oxygen (1O 2). In 0.4 N -CG/PMS system, 1O 2 and •O 2 − were proved to be the predominant reactive oxygen species (ROSs) in BaP degradation, as well as •OH and SO 4 •− made certain contributions. To sum up, this work provided a promising strategy for synthesis of CG-based catalysts by chemical inertness conversion of carbon fracture via N -doping for PMS activation and opened a novel perspective for environmental remediation of hydrophobic and hydrophilic contaminants pollution. [ABSTRACT FROM AUTHOR]

The general strategy for n‐type organic thermoelectric is to blend n‐type conjugated polymer hosts with small molecule dopants. In this work, all‐polymer n‐type thermoelectric is reported by dissolving a novel n‐type conjugated polymer and a polymer dopant, poly(ethyleneimine) (PEI), in alcohol solution, followed by spin‐coating to give polymer host/polymer dopant blend film. To this end, an alcohol‐soluble n‐type conjugated polymer is developed by attaching polar and branched oligo (ethylene glycol) (OEG) side chains to a cyano‐substituted poly(thiophene‐alt‐co‐thiazole) main chain. The main chain results in the n‐type property and the OEG side chain leads to the solubility in hexafluorineisopropanol (HFIP). In the polymer host/polymer dopant blend film, the Coulombic interaction between the dopant counterions and the negatively charged polymer chains is reduced and the ordered stacking of the polymer host is preserved. As a result, the polymer host/polymer dopant blend exhibits the power factor of 36.9 µW m−1 K−1, which is one time higher than that of the control polymer host/small molecule dopant blend. Moreover, the polymer host/polymer dopant blend shows much better thermal stability than the control polymer host/small molecule dopant blend. This research demonstrates the high performance and excellent stability of all‐polymer n‐type thermoelectric. [ABSTRACT FROM AUTHOR]

Severe shuttle effect and sluggish reaction kinetics caused by lithium‐polysulfides have always been the dominant factor to reduce the actual energy density of lithium–sulfur batteries. It's very important to simultaneously balance the surface adsorption and redox conversion of the lithium‐polysulfides. Herein, a TiO2/TiN heterostructure and in situ N‐doping modified multifunctional carbon interlayer is designed and constructed using a melamine foam as the matrix material at a relatively low temperature and without NH3 atmosphere. Interestingly, TiO2 nano‐particles decorated on the N‐enriched melamine carbon foam can be partially in situ transformed into TiN during pyrolysis process. Based on the support of highly conductive and interconnected carbon skeletons, the N heteroatom and TiO2/TiN show good synergetic adsorption and conversion of the soluble lithium‐polysulfides, whilst boosting the electrochemical performance of lithium–sulfur batteries. Consequently, when used the multifunctional carbon interlayer, the Super P/sulfur cathode based lithium–sulfur battery delivers a high initial discharge capacity of 814 mAh g−1 at a high current rate of 2.0 C and maintain the 548 mAh g−1 after 500 cycles. Even with the high sulfur loading of 7.5 mg cm−2 and low E/S ratio of 4.7 µL mg−1, an acceptable areal capacity of 8.2 mAh cm−2 can be obtained. [ABSTRACT FROM AUTHOR]

Amorphous C has the advantages of low-cost and adjustable interlayer spacing, which exhibits great potential in K+ storage. However, the sluggish diffusion kinetics of K+ in the C lattice and mediocre capacity limit the use of C materials as anodes in potassium-ion batteries (PIBs). Herein, we develop an N-doped hierarchical porous C derived from lignite by a simple carbonization activation process. The resulting N-doped hierarchical porous C delivers reversible capacities of 314 mAh g−1 after 100 cycles at 0.1 A g−1 and 124.3 mAh g−1 after 1500 cycles at 1.0 A g−1, when utilized as anode materials for PIBs. The outstanding reversible capacity and excellent cyclic performance can attribute to the porous structure and N doping, which improves electronic conductivity and facilitates K+ insertion. This research aids in the development of high-performance anode materials for PIBs and provides some insights into the manufacturing of heteroatom-doped C materials. [ABSTRACT FROM AUTHOR]

Abstract Fullerene derivatives are highly attractive materials in solar cells, organic thermoelectrics, and other devices. However, the intrinsic low electron mobility and electrical conductivity restrict their potential device performance, such as perovskite solar cells (PSCs). Herein, we successfully enhanced the electric properties and morphology of phenyl‐C61‐butyric acid methyl ester (PCBM) by n‐doping it with a benzimidazoline derivative, 9‐(1,3‐dimethyl‐2,3‐dihydro‐1H‐benzoimidazol‐2‐yl)‐julolidine (JLBI‐H) via a solution process. We found the n‐doping can not only improve the conductivity and optimize the band alignment but also enable the PCBM to have a constantly strong charge extraction ability in a wide temperature from 173 to 373 K, which guarantees a stable photovoltaic performance of the corresponding PSCs under a wide range of operating temperatures. With the JLBI‐H‐doped PCBM, we improved the efficiency from 17.9% to 19.8%, along with enhanced stability of the nonencapsulated devices following the aging protocol of ISOS‐D‐1.

It is still a great challenge to reasonably design green, low cost, high activity and good stability catalysts for overall water splitting (OWS). Here, we introduce a novel catalyst with ferric niobate (FeNbO4) in‐situ growing in honey‐derived porous carbon of high specific surface area, and its catalytic activity is further enhanced by micro‐regulation (oxygen vacancy and N‐doping). From the experimental results and density functional theory (DFT) calculations, the oxygen vacancy in catalyst FeNbO4‐x@NC regulates the local charge density of active site, thus increasing conductivity and optimizing hydrogen/oxygen species adsorption energy. FeNbO4 in‐situ grows within N‐doping honey‐derived porous carbon, which can enhance active specific surface area exposure, strengthen gaseous substances escape rate, and accelerate electrons/ions transfer and electrolytes diffusion. Moreover, in‐situ Raman also confirms O‐species generation in oxygen evolution reaction (OER). As a result, the catalyst FeNbO4‐x@NC shows good electrochemical performance in OER, HER and OWS. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The investigation of n‐type doping holds a significant interest for the application of thermoelectrics. Herein, the doping of an indandione‐terminated compound Q‐4F with a singlet open‐shell ground state was studied using two n‐dopants N‐DMBI and LCV. Both of these two dopants can effectively dope Q‐4F due to the large offset between the singly occupied molecular orbital (SOMO) of dopants and the lowest unoccupied molecular orbital (LUMO) of Q‐4F. N‐DMBI has a higher doping ability than LCV as demonstrated by the UV‐vis‐NIR and EPR measurements. However, in comparison to N‐DMBI doped Q‐4F, LCV doped system exhibits much higher electrical conductivity and power factor due to its unperturbed molecular packing and favorable morphology after doping. The optimal conductivity of LCV doped Q‐4F is 7.16 × 10–2 ± 0.16 S·cm–1 and the highest power factor reaches 12.3 ± 0.85 μW·m–1·K–2. These results demonstrate that the modulation of n‐dopants is a powerful strategy to balance the doping efficiency and microstructure toward a maximum thermoelectric performance. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The investigation of n‐type doping holds a significant interest for the application of thermoelectrics. Herein, the doping of an indandione‐terminated compound Q‐4F with a singlet open‐shell ground state was studied using two n‐dopants N‐DMBI and LCV. Both of these two dopants can effectively dope Q‐4F due to the large offset between the singly occupied molecular orbital (SOMO) of dopants and the lowest unoccupied molecular orbital (LUMO) of Q‐4F. N‐DMBI has a higher doping ability than LCV as demonstrated by the UV‐vis‐NIR and EPR measurements. However, in comparison to N‐DMBI doped Q‐4F, LCV doped system exhibits much higher electrical conductivity and power factor due to its unperturbed molecular packing and favorable morphology after doping. The optimal conductivity of LCV doped Q‐4F is 7.16 × 10–2 ± 0.16 S·cm–1 and the highest power factor reaches 12.3 ± 0.85 μW·m–1·K–2. These results demonstrate that the modulation of n‐dopants is a powerful strategy to balance the doping efficiency and microstructure toward a maximum thermoelectric performance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhejiang University: Science A is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main hindrances in commercializing hydrogen fuel cells are the high catalyst cost, sluggish oxygen reduction reaction (ORR) kinetics, and low durability over long cycling. Herein, a low‐Pt‐based efficient cathode catalyst decorated on nitrogen‐doped carbon nanotube (CNT) support is developed. The effect of N doping and chemical etching of CNTs on the performance of proton exchange membrane fuel cells (PEMFC) are demonstrated in this work. Half‐cell studies showed that Pt decorated N‐doped etched carbon nanotubes (Pt/NECNT) exhibit higher electrochemical surface area, onset potential, specific activity, and mass activity than Pt/CNT, Pt/ECNT, Pt/NCNT, and commercial Pt/C samples. In contrast to the commercial Pt/C catalyst, minimal loss in limiting current density and half‐wave potential is observed for Pt/NECNT catalyst even after the 10000th ADT cycle. From single‐cell study, the peak power density of 950 mW cm−2 and operational power density of 840 mW cm−2 (at 0.6 V) are obtained using Pt/NECNT cathode catalyst at 80 °C with low Pt loading. The remarkable enhancement in the electrocatalytic activity, kinetic property, and high durability of Pt/NECNT are ascribed to the N doping and surface modification of CNT support. [ABSTRACT FROM AUTHOR]

Highly conducting nanomaterials have garnered significant attention owing to their potential application in Li‐ion batteries for stable electrodes. However, concerns persist regarding their dispersion and effective hybridization with active materials. This study reports a novel approach to enhance Si‐based anode materials using less defective graphene oxide (C‐GO) and highly oxidized single‐walled carbon nanotubes (C‐SWCNTs) fabricated using chlorate‐based oxidation. The method involves encapsulating Si alloy (SiA) particles with C‐GO and C‐SWCNTs, eliminating the need for additional additives. Composite structures with lithiophilic N‐doped SWCNTs and highly crystalline reduced C‐GO coatings on SiA surfaces are created through spray drying and subsequent chemical reduction. This unique combination yields high capacities, stable retention behaviors, and remarkable initial capacities (1224 mAh g−1) with excellent retention rates (82.3% at 100 cycles, 0.1 C). A LIB full‐cell with a SiA/nanocarbon anode exhibited a high energy density of 350 Wh kg−1, while maintaining 65% capacity retention after 200 cycles. The findings demonstrate the potential of this hybrid approach, which eliminates the need for other conducting additives while maintaining a minimal binder content (5 wt.%). This study presents a promising approach for enhancing Si‐based anode materials in lithium‐ion batteries, addressing the dispersion and hybridization challenges in nanomaterial‐enabled electrode design. [ABSTRACT FROM AUTHOR]

Synthesizing lightweight, thin–profile, and high–performance microwave absorbers has emerged as an urgent research topic. A promising strategy for carbon–based materials to achieve these attributes is to rationally construct heterostructures. Herein, 0.89–1.54 at.% nitrogen(N)–doped carbon onion nanotube chains (NCONCs) were produced by blending CONCs harvested from candle combustion with HH 4 Cl and subjecting them to heating at 300–400 °C for 3 h. The hinge–like NCONCs revealed numerous electron transport paths, facilitating the formation of multi–tiered conduction networks. The N–doping introduced C–N groups and interfaces into the CONCs, which yielded extensive dipole and interfacial polarization. Simultaneously, the 1.14 at.% N–doping endowed NCONC–400 with suitable conductivity, thereby ensuring excellent impedance matching. The resulting synergistic effect of impedance matching and electromagnetic wave attenuation was clearly observed. Specifically, NCONC–400 exhibited exceptional performance with a maximum effective absorption bandwidth of 4.71 GHz and a peak reflection loss of –35.47 dB at 1.4 mm. The radar cross–section reduction demonstrated by NCONC–400 composites reached 21.43 dB cm2. These impressive results prove the distinctive advantages of CONCs in tailoring performance and optimizing impedance matching, which are appealing for lightweight and efficient microwave absorbers. [ABSTRACT FROM AUTHOR]