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Borophenes have sparked considerable interest owing to their fascinating physical characteristics and diverse polymorphism. However, borophene nanoribbons (BNRs) with widths less than 2 nm have not been achieved. Herein, we report the experimental realization of supernarrow BNRs. Combining scanning tunneling microscopy imaging with density functional theory modeling and ab initio molecular dynamics simulations, we demonstrate that, under the applied growth conditions, boron atoms can penetrate the outermost layer of Au(111) and form BNRs composed of a pair of zigzag (2,2) boron rows. The BNRs have a width self‐contained to ∼1 nm and dipoles at the edges to keep them separated. They are embedded in the outermost Au layer and shielded on top by the evacuated Au atoms, free of the need for post‐passivation. Scanning tunneling spectroscopy reveals distinct edge states, primarily attributed to the localized spin at the BNRs' zigzag edges. This work adds a new member to the boron material family and introduces a new physical feature to borophenes. [ABSTRACT FROM AUTHOR]

The photovoltaic devices offer promising eco‐friendly solution for self‐powered flexible electronics. However, their fabrication on flexible substrate is not easy due to mismatches between the requirements of conventional microfabrication and the thermal, and mechanical features of the substrates. Herein, direct roll printed nanoscale photoactive electronic layers are presented, which are further processed to develop ≈315 µm2 sized miniaturized photovoltaic microcells. Using a set of 32 microcells, connected in parallel configuration, indoor light harvesting is shown at a maximum power density of ≈10 µW cm−2 under white LED illumination. Further, the dual functionality of developed microcells i.e., energy harvesting as well as wideband photodetection is demonstrated. As self‐powered photo sensors the developed photovoltaic microcells exhibit distinctive photo responses under white LED‐UV (365 nm)‐ NIR (850 nm) light illumination, with exceptionally high‐speed response (rise time τRise = 205 µs and fall time τFall = 2000 µs), and a peak responsivity of 2.48 A W−1 to UV light at zero bias voltage. The presented results show the potential usage of printed multifunctional photovoltaic microcells in a wide variety of applications such as self‐powered wearable and flexible electronic systems for health monitoring and indoor robotics. [ABSTRACT FROM AUTHOR]

The photochemical cyclodehydrochlorination (CDHC) reaction has recently been used to prepare a wide variety of polycyclic aromatic hydrocarbons and graphene nanoribbons (GNRs). However, the parameters affecting the efficiency of this reaction have been scarcely studied. In this work, we investigated how the reaction conditions influence the outcome of the reaction. The effect of functional groups on the different phenyl rings of the o‐terphenyl scaffold was also studied. The reaction kinetics follow the same trend as Hammett's constant when electron‐donating and electron‐withdrawing groups are present on the ring bearing the chlorine. The CDHC reaction can be successfully performed using less energetic 365 nm light in the presence of a triplet sensitizer. Computational results provide insight on the reaction mechanism, notably by identifying its three intermediate structures as well as its limiting step. [ABSTRACT FROM AUTHOR]

In this study, we introduce a comprehensive investigation into the buckling behavior of carbon nanotubes (CNTs) using a combined approach of quantum mechanics and molecular mechanics methods. A novel aspect of our research lies in the exploration of the quantum effects of fine scaling on the buckling behavior of finite‐length nanotubes across various dimensions and chiralities. Specifically, we analyze the critical buckling strain variations in CNTs with distinct lengths, diameters, and chiralities, revealing pronounced differences influenced by atomic arrangement and the type of structure used in nanotube construction. Our findings elucidate that at smaller dimensions, nn2$$ \left(\ n,\frac{n}{2}\right) $$ nanotubes exhibit a higher critical buckling strain than other chiralities, while zigzag atomic arrangements demonstrate greater resistance to torsional loading at larger diameters. Additionally, we compare the buckling behavior of nanotubes obtained by wrapping armchair and zigzag nanosheets, highlighting differential resistance trends. This research not only underscores the critical role of quantum effects in determining nanotube buckling but also provides valuable insights into the nuanced influences of atomic arrangement and nanosheet type on the mechanical properties of CNTs. Thus, our work contributes a novel perspective to the field, bridging the gap between quantum mechanics and the mechanical behavior of nanostructures, which has significant implications for the design and application of nanoscale materials [ABSTRACT FROM AUTHOR]

Metalloborophene, characterized by the presence of metal‐centered boron wheels denoted as M©Bn, has garnered considerable attention in recent years due to its versatile properties and potential applications in fields such as electronics, spintronics, and catalysis. However, the experimental verification of metalloborophene is challenging, mainly due to the unconventional 2D boron networks. In this study, scanning tunneling microscopy, X‐ray photoelectron spectroscopy, low energy electron diffraction, and first‐principles calculations are employed to unveil Cu©B8 metalloborophene nanoribbons formed via spontaneous alloying after the deposition of boron on a heated Cu(110) substrate under ultrahigh vacuum condition. The thermodynamically preferred precursor, the anchoring of boron network to metal atoms, and anisotropic lattice mismatch are identified as pivotal factors in the formation of these metalloborophene nanoribbons. This discovery expands the repertoire of 2D materials and offers a potential pathway for the synthesis of other metalloborophenes. [ABSTRACT FROM AUTHOR]

This study delves into the thermoelectric properties of armchair black phosphorene nanoribbons while considering the presence of line edge roughness. Employing the tight‐binding method in conjunction with non‐equilibrium Green's function techniques and Landauer formulas, the impact of various parameters on thermoelectric performance is explored. These findings reveal that the electrical conductivity and, consequently, the power factor exhibits an increasing trend with expanding ribbon length and width. This behavior can be attributed to heightened collision rates, particularly in narrow ribbons, induced by line edge roughness as length increases. Remarkably, the Seebeck coefficient at the Fermi energy corresponding to the maximum power factor remains nearly constant across different widths, lengths, temperatures, and transport regimes. Furthermore, the thermoelectric figure of merit (ZT) demonstrates a positive correlation with both ribbon length and width. In narrow widths and lengths ≈1000 nm, the power factor and figure of merit exhibit an upward trend with ribbon width. However, with further increases in ribbon width, the influence of line edge roughness on thermal conductivity diminishes. Consequently, the figure of merit decreases due to the rise in thermal conductivity. Notably, the thermoelectric figure of merit is higher for short and narrow ribbons and long and wider ribbons. [ABSTRACT FROM AUTHOR]

Recent studies dedicated to layered van der Waals crystals have attracted significant attention to magnetic atomically thin crystals offering unprecedented opportunities for applications in innovative magnetoelectric, magneto‐optic, and spintronic devices. The active search for original platforms for the low‐dimensional magnetism study has emphasized the entirely new magnetic properties of two dimensional (2D) semiconductor CrSBr. Herein, for the first time, the electrochemical exfoliation of bulk CrSBr in a non‐aqueous environment is demonstrated. Notably, crystal cleavage governed by the structural anisotropy occurred along two directions forming atomically thin and few‐layered nanoribbons. The exfoliated material possesses an orthorhombic crystalline structure and strong optical anisotropy, showing the polarization dependencies of Raman signals. The antiferromagnetism exhibited by multilayered CrSBr gives precedence to ferromagnetic ordering in the revealed CrSBr nanostructures. Furthermore, the potential application of CrSBr nanoribbons is pioneered for electrochemical photodetector fabrication and demonstrates its responsivity up to 30 µA cm−2 in the visible spectrum. Moreover, the CrSBr‐based anode for lithium‐ion batteries exhibited high performance and self‐improving abilities. This anticipates that the results will pave the way toward the future study of CrSBr and practical applications in magneto‐ and optoelectronics. [ABSTRACT FROM AUTHOR]

Area‐selective deposition (ASD) is a forefront nanopatterning technique gaining substantial attention in the semiconductor industry. While current research primarily addresses single‐material ASD, exploring multi‐material ASD is essential for mitigating complexity in advanced nanopatterning. This study describes molybdenum hexafluoride (MoF6)‐mediated fluorination/passivation of the hydroxylated SiO2 (SiO2‒OH) at 250 °C as a new method to pacify nucleation during subsequent ZnO and TiO2 atomic layer deposition (ALD). In contrast, Al2O3 ALD is not passivated on the fluorinated SiO2 (SiO2‒F). The study further shows that Mo ALD using MoF6 and silane (1 wt% SiH4 in Ar) selectively proceeds on hydrogen‐terminated Si (Si‒H), whereas SiO2‒OH becomes fluorine‐passivated without observable Mo deposition. This enables subsequent ZnO and TiO2 ASD on Mo versus SiO2‒F, as confirmed by X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and scanning transmission electron microscopy (STEM). Proposed growth and inhibition mechanisms highlight the importance of the metal oxide precursor in achieving selectivity. Taken together, self‐aligned Mo/ZnO and Mo/TiO2 nanoribbons are demonstrated on coplanar nanoscale Si‒H/SiO2‒OH patterns by sequentially integrating two individual ASD processes: 1) Mo ASD on Si‒H versus SiO2‒OH; and 2) ZnO or TiO2 ASD on Mo versus SiO2‒F. This work highlights the potential for this approach in new ASD systems. [ABSTRACT FROM AUTHOR]

Flexible wearable electronics enable an in situ and real‐time measurement of human physiology and micro‐environment. Although large‐scale production of flexible wearable electronics is demonstrated using direct printing techniques, the "wet" nature of these techniques requires multiple procedures and chemicals to prepare printable inks, increasing the complexity and cost. Here, a dry‐wet hybrid direct printing is developed for the mass production of flexible wearable photodetectors, in which a "dry" direct laser writing and a "wet" screen printing are employed to fabricate laser‐induced graphene as electrode layer and zinc oxide as photosensitive layer, respectively. The liquid‐free fabrication of LIG significantly reduces the complexity and cost of the production. An automatic conveyor belt is designed to realize continuous‐flow manufacturing. The photodetectors demonstrate good ultraviolet (UV) photodetection performances, such as a photo‐to‐dark current ratio (Iphoto/Idark) of 5.67 × 105, approaching the record of similar devices. The manufacturing system presents a high reproducibility, considering that Iphoto/Idark only fluctuates within 7.10%. The flexible photodetectors are worn as wristbands after being integrated with a data acquisition and transmission circuit. UV intensity is real‐time monitored on a self‐developed mobile application. The continuous‐flow manufacturing based on the developed dry‐wet hybrid direct printing sheds light on the mass production of flexible wearable electronics. [ABSTRACT FROM AUTHOR]

Although the transport of topological edge states may be insensitive to impurities, impurities may induce the interedge scattering and backscattering in topological nanoribbons due to the finite size effect. It may be interesting to compare the transport of topological edge states with that of trivial edge states in nanoribbons. Here, the quantum transport of edge states in the Sn-doped SbH nanoribbons using the density functional theory combined with nonequilibrium Green's function method is studied. Both topological and trivial edge states can be found in the zigzag SbH nanoribbons. The impurity generates a higher barrier near the doping position and leads to the scattering of the states. From calculations, the transmission of topological edge states can be smaller than that of trivial edge states due to the antiresonance behavior. Compared with topological edge states, the transport of trivial edge states is more sensitive to the impurity position. Besides, the edge impurity is more likely to induce scattering for both topological and trivial edge states than the central impurity in narrow SbH nanoribbons, since the transport channels are limited to the edges. This study may be helpful for understanding the transport of edge states in nanoribbons. [ABSTRACT FROM AUTHOR]

Polar 2D macromolecular structures have attracted significant attention because of their ferroelectricity and ferro‐magnetism. However, it is challenging to synthesize them experimentally because dipoles or spins of these macromolecules tend to cancel each other. So far, there has been no successful strategy for assembling macromolecules in a unidirectional manner, achieving stereoregular polymerization on metal surfaces, and creating polar 2D polymer crystals. Recent progress in molecular assembly, on‐surface polymer synthesis, and direct control of molecules using electric field applications provides an opportunity to develop such strategies. In this regard, we first review past studies on chiral and achiral molecular assembly, on‐surface polymer synthesis, and orientation control of polar molecules. Then, we discuss our newly developed approach called “vectorial on‐surface synthesis”, which is based on “dynamic chirality” of compass precursors, stereoselective polymerization, and favorable interchain interactions originating from CH‐π interactions. Finally, we conclude with a prospective outlook. [ABSTRACT FROM AUTHOR]

The repair of bone defects in diabetes remains a major challenge in the field of biomedicine because of the disturbance of bone immune homeostasis and the susceptibility of exposed wounds to bacterial infection. Clinically, immunoregulation by removing excessive reactive oxygen species (ROS) effectively promotes diabetic bone defect repair. However, aggressive ROS clearance can disrupt ROS homeostasis, making ROS‐mediated polarization of M2 macrophages in the process of tissue healing of diabetes be difficult. Herein, an ultrathin defective tungsten oxide (WOx) nanoribbon with high oxygen vacancies to simultaneously achieve moderate scavenging of ROS and high broad‐spectrum photothermal antibacterial activity to promote diabetic bone defect repair is reported. It is demonstrated that the moderate ROS clearance ability of WOx nanoribbons can remodel metabolic patterns for achieving 86.3% M2 macrophage induction in a high glucose microenvironment. This high induction efficiency combined with excellent photothermal antibacterial ability of WOx nanoribbons markedly alleviated the inflammatory reaction and efficiently facilitated the repair of bone defects infected with methicillin‐resistant Staphylococcus aureus (S. aureus) in C57BLKS/J (BKS)‐diabetic (BKS‐db) mice. [ABSTRACT FROM AUTHOR]

By leveraging the principles of electromagnetic theory and materials science, the characteristics of dielectric polymer composites can be optimized, eliminating repetitive trial‐and‐error in their application as electromagnetic absorbers (EMAs). Herein, a systematic framework for optimizing the thickness and composition of double‐layer EMAs is proposed, using a combination of transmission line, Debye relaxation, and Maxwell–Garnett theories. Following theoretical optimization, a double‐layered electrospun EMA is fabricated, which comprises a ≈1.17 mm thick matrix of styrene–butadiene–styrene (SBS) decorated with MXene on its fibrous structure. The second SBS layer, with a thickness of ≈0.52 mm, incorporates a hybrid of MXene and graphene nanoribbons (GNR) as conductive additives. The EMA exhibits durable electrical performance after 2000 tensile cycles, owing to the surface chemistry engineering and the novel in situ assembly technique. It is capable of shielding 99.9% of the incident wave and >80% absorptivity (A) over almost the entire Ku‐band. The EMA also exhibits desirable mechanical characteristics, such as >300% stretchability and full twist and wrinkle recoveries, making it an excellent choice for protective attire applications. Additionally, the introduced approach provides solutions for the advancement of tailorable polymer composite EMAs, with respect to specific criteria of the target wave frequency, effective absorption bandwidth, and absorption levels. [ABSTRACT FROM AUTHOR]

Understanding the mechanism underlying the formation of quantum‐sized semiconductor nanocrystals is crucial for controlling their synthesis for a wide array of applications. However, most studies of 2D CdSe nanocrystals have relied predominantly on ex situ analyses, obscuring key intermediate stages and raising fundamental questions regarding their lateral shapes. Herein, the formation pathways of two distinct quantum‐sized 2D wurtzite‐CdSe nanocrystals — nanoribbons and nanosheets — by employing a comprehensive approach, combining in situ small‐angle X‐ray scattering techniques with various ex situ characterization methods is studied. Although both nanostructures share the same thickness of ≈1.4 nm, they display contrasting lateral dimensions. The findings reveal the pivotal role of Se precursor reactivity in determining two distinct synthesis pathways. Specifically, highly reactive precursors promote the formation of the nanocluster‐lamellar assemblies, leading to the synthesis of 2D nanoribbons with elongated shapes. In contrast, mild precursors produce nanosheets from a tiny seed of 2D nuclei, and the lateral growth is regulated by chloride ions, rather than relying on nanocluster‐lamellar assemblies or Cd(halide)2–alkylamine templates, resulting in 2D nanocrystals with relatively shorter lengths. These findings significantly advance the understanding of the growth mechanism governing quantum‐sized 2D semiconductor nanocrystals and offer valuable guidelines for their rational synthesis. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries have attracted wide attention as high‐energy‐density energy storage devices, but their practical applications are hindered by the severe shuttle effect and sluggish kinetics of lithium polysulfides (LiPSs). To address these challenges, polar mediators are employed to chemisorb and catalyze LiPSs, but most of them suffer from low electronic conductivity and poor catalytic activity. Here, a novel strategy is reported to enhance both properties by dispersing Fe(III) atoms in VO2 nanoribbons(Fe‐VO2), creating electronic metal‐support interactions (EMSI) that modulate the electronic structure and charge transfer of VO2. Theoretical calculations reveal that EMSI lowers the energy barrier for the decomposition of Li2S from 1.60 to 1.32 eV and increases the electronic conductivity of VO2. Fe doping reduces the Li‐ions diffusion barrier from 1.42 eV in VO2 to 0.99 eV in Fe‐VO2. The Fe‐VO2 catalyst shows strong adsorption and fast converstion of LiPSs, resulting in high energy density and long cycling life of Li‐S batteries. The cathode with Fe‐VO2 maintains a higher capacity retention of 67% after 500 cycles at 1 C, compared with 52.4% and 53.6% for the carbon black based cathode and VO2 based cathode, respectively. This work demonstrates the potential of EMSI for designing efficient catalysts for Li–S batteries and provides new insights into the electronic structure engineering of polar mediators. [ABSTRACT FROM AUTHOR]

Porous two‐dimensional (2D) nanographene structures are materials with vast potentials in several areas of research with varied applications. The porous structures of these 2D‐materials offer multiple applications in the field of nanochemistry including sequestration of toxic metal ions as they possess large surface areas, enhanced electrical and electronic properties, and high mechanical flexibility. Their porous structures facilitate the creation of highly efficient electrodes, which could significantly improve the performance of batteries and other energy storage technologies. Topological descriptors are powerful tools for characterizing their structures and predicting the properties of molecules and thus have a number of applications. We compute the analytical expressions for degree‐based and Szeged‐type topological descriptors and their information‐theoretic entropies. In addition, we perform a comparative analysis of the scaled bond‐wise entropies between nanoporous graphenes and rectangular kekulene structures with comparable sizes. Furthermore, we predict the 13C and proton NMR spectral patterns of these materials using graph‐theoretical techniques. [ABSTRACT FROM AUTHOR]

Modern electronic devices are moving toward miniaturization and integration. Therefore, achieving electrical control of magnetization effectively in 1D materials represents a promising field for the practical applications in memory elements. Herein, it is discovered, from first‐principles calculations, that an electric‐field‐tunable bipolar linear magnetoelectric effect can be realized in 1D antiferromagnets based on double‐Gd‐adsorbed graphene nanoribbon with four zigzag carbon chains (2Gd‐4ZGNR). It is found that, compared with the bare 4ZGNR, the adsorption of two Gd atoms on the 4ZGNR reduces the bandgap. As a result, 2Gd‐4ZGNR transits from antiferromagnetic semiconductor to ferrimagnetic metal at a relatively low critical external transverse (perpendicular) electric field, where the net magnetic moment can be induced. The antiferromagnetism and inversion‐symmetrical crystal structure further allow to realize a bipolar linear magnetoelectric effect, where the 2Gd‐4ZGNR forms two groups of independent linear magnetic response states, acting as a magnetoelectric memory element. [ABSTRACT FROM AUTHOR]

Despite the impressive advances in the synthesis of atomically precise graphene nanostructures witnessed during the last decade, advancing in compositional complexity faces major challenges. The concept of introducing the desired functional groups or dopants in the molecular precursor often fails due to their lack of stability during the reaction path. Here, a study on the stability of different pyridine and pyrimidine moieties during the on‐surface synthesis of graphene nanoribbons on Au(111) is presented. Combining bond‐resolved scanning tunneling microscopy with X‐ray photoelectron spectroscopy, the thermal evolution of the nitrogen dopants throughout the whole reaction sequence is tracked. A comparative experimental and ab initio electronic characterization confirms the presence of dopants in the final structures, revealing also that the pyridinic nitrogen leads to a significant band downshift. The results demonstrate that, by using synthetic strategies to lower the reaction temperatures, one can preserve specific N‐heterocycles throughout all the reaction steps of the synthesis of graphene nanoribbons and beyond the interibbon coupling reaction that leads to nanoporous graphene. [ABSTRACT FROM AUTHOR]

Carbohydrates are intriguing biomolecules possessing diverse biological activities, including immune stimulating capability. However, their biomedical applications have been limited by their complex and heterogeneous structures. In this study, we have utilized a self‐assembling glycopeptide conjugate (GPC) system to produce uniform nanoribbons appending homogeneous oligosaccharides with multivalency. This system successfully translates the nontrivial structural differences of oligomannoses into varied binding affinities to C‐type lectin receptors (CLRs). We have shown that GPCs could promote the CLR‐mediated endocytosis of ovalbumin (OVA) antigen, and two mannotriose‐modified peptides F3m2 and F3m5 exhibit potent activity in inducing antigen‐presenting cell maturation, as indicated by increased CD86 and MHCII expression. In vivo studies demonstrated that GPCs, combined with OVA antigen, significantly enhanced OVA‐specific antibody production. Specifically, F3m2 and F3m5 exhibited the highest immunostimulatory effects, eliciting both Th1‐ and Th2‐biased immune responses and promoting differentiation of CD4+ and CD8+ T cells. These findings highlight the potential of GPCs as vaccine adjuvants, and showcase their versatility in exploiting the biological functions of carbohydrates. [ABSTRACT FROM AUTHOR]

Graphene plasmonic modulators can manipulate the mid‐infrared light in transmission mode, which is currently challenging for traditional liquid crystal and digital micromirror devices, opening up a new avenue for infrared scene projection, infrared optical communication, and hyper spectra imaging. Nevertheless, their efficiencies are not high enough due to the single‐layer atomic thickness and low free carrier density of graphene. Here, it is demonstrated that the modulation efficiency can be significantly improved by enhancing the asymmetric light‐plasmon coupling. A general theoretical model is established to describe the modulation behaviors of the modulator, revealing the critical role of the asymmetric coupling rate. By using dielectric environment engineering and graphene structure design experimentally to enhance the asymmetric coupling rate from 0.45×1012 to 7.05×1012 s−1, the modulation efficiency has been improved from 4% to 41% at 1530 cm−1, while maintaining the bandwidth as large as 230 cm−1. The modulator outperforms previous transmission‐type graphene plasmonic modulators in both efficiency and bandwidth, presenting great potential in next‐generation infrared integrated photonics platforms. [ABSTRACT FROM AUTHOR]

Carbohydrates are intriguing biomolecules possessing diverse biological activities, including immune stimulating capability. However, their biomedical applications have been limited by their complex and heterogeneous structures. In this study, we have utilized a self‐assembling glycopeptide conjugate (GPC) system to produce uniform nanoribbons appending homogeneous oligosaccharides with multivalency. This system successfully translates the nontrivial structural differences of oligomannoses into varied binding affinities to C‐type lectin receptors (CLRs). We have shown that GPCs could promote the CLR‐mediated endocytosis of ovalbumin (OVA) antigen, and two mannotriose‐modified peptides F3m2 and F3m5 exhibit potent activity in inducing antigen‐presenting cell maturation, as indicated by increased CD86 and MHCII expression. In vivo studies demonstrated that GPCs, combined with OVA antigen, significantly enhanced OVA‐specific antibody production. Specifically, F3m2 and F3m5 exhibited the highest immunostimulatory effects, eliciting both Th1‐ and Th2‐biased immune responses and promoting differentiation of CD4+ and CD8+ T cells. These findings highlight the potential of GPCs as vaccine adjuvants, and showcase their versatility in exploiting the biological functions of carbohydrates. [ABSTRACT FROM AUTHOR]

Calcium cobaltite Ca3Co4−xO9+δ (CCO) is a promising p‐type thermoelectric (TE) material for high‐temperature applications in air. The grains of the material exhibit strong anisotropic properties, making texturing and nanostructuring mostly favored to improve thermoelectric performance. On the one hand multitude of interfaces are needed within the bulk material to create reflecting surfaces that can lower the thermal conductivity. On the other hand, low residual porosity is needed to improve the contact between grains and raise the electrical conductivity. In this study, CCO fibers with 100% flat cross sections in a stacked, compact form are electrospun. Then the grains within the nanoribbons in the plane of the fibers are grown. Finally, the nanoribbons are electrospun into a textured ceramic that features simultaneously a high electrical conductivity of 177 S cm−1 and an immensely enhanced Seebeck coefficient of 200 µV K−1 at 1073 K are assembled. The power factor of 4.68 µW cm−1 K−2 at 1073 K in air surpasses all previous CCO TE performances of nanofiber ceramics by a factor of two. Given the relatively high power factor combined with low thermal conductivity, a relatively large figure‐of‐merit of 0.3 at 873 K in the air for the textured nanoribbon ceramic is obtained. [ABSTRACT FROM AUTHOR]

Recently, there is much interest in narrow graphene‐like nanoribbons in view of their exceptional electronic and magnetic properties. Of special interest are ultranarrow zigzag edge nanoribbons because they can have magnetic moments at the edges. Of course, it is also well known that if there are antidots (nanopores) in a system, its physical properties are strongly affected, too. In this letter, the comparative studies of graphene and phosphorene nanoribbons are presented, with emphasis on edge as well as antidot effects. It is shown that phosphorene has quite large magnetic moments on both external and internal zigzag edges and it is a half‐metal for certain electron concentrations. So phosphorene is a very attractive material for spintronic applications. [ABSTRACT FROM AUTHOR]

Structurally defined graphene nanoribbons (GNRs) have emerged as promising candidates for nanoelectronic devices. Low band gap (<1 eV) GNRs are particularly important when considering the Schottky barrier in device performance. Here, we demonstrate the first solution synthesis of 8‐AGNRs through a carefully designed arylated polynaphthalene precursor. The efficiency of the oxidative cyclodehydrogenation of the tailor‐made polymer precursor into 8‐AGNRs was validated by FT‐IR, Raman, and UV/Vis‐near‐infrared (NIR) absorption spectroscopy, and further supported by the synthesis of naphtho[1,2,3,4‐ghi]perylene derivatives (1 and 2) as subunits of 8‐AGNR, with a width of 0.86 nm as suggested by the X‐ray single crystal analysis. Low‐temperature scanning tunneling microscopy (STM) and solid‐state NMR analyses provided further structural support for 8‐AGNR. The resulting 8‐AGNR exhibited a remarkable NIR absorption extending up to ∼2400 nm, corresponding to an optical band gap as low as ∼0.52 eV. Moreover, optical‐pump TeraHertz‐probe spectroscopy revealed charge‐carrier mobility in the dc limit of ∼270 cm2 V−1 s−1 for the 8‐AGNR. [ABSTRACT FROM AUTHOR]

Structurally defined graphene nanoribbons (GNRs) have emerged as promising candidates for nanoelectronic devices. Low band gap (<1 eV) GNRs are particularly important when considering the Schottky barrier in device performance. Here, we demonstrate the first solution synthesis of 8‐AGNRs through a carefully designed arylated polynaphthalene precursor. The efficiency of the oxidative cyclodehydrogenation of the tailor‐made polymer precursor into 8‐AGNRs was validated by FT‐IR, Raman, and UV/Vis‐near‐infrared (NIR) absorption spectroscopy, and further supported by the synthesis of naphtho[1,2,3,4‐ghi]perylene derivatives (1 and 2) as subunits of 8‐AGNR, with a width of 0.86 nm as suggested by the X‐ray single crystal analysis. Low‐temperature scanning tunneling microscopy (STM) and solid‐state NMR analyses provided further structural support for 8‐AGNR. The resulting 8‐AGNR exhibited a remarkable NIR absorption extending up to ∼2400 nm, corresponding to an optical band gap as low as ∼0.52 eV. Moreover, optical‐pump TeraHertz‐probe spectroscopy revealed charge‐carrier mobility in the dc limit of ∼270 cm2 V−1 s−1 for the 8‐AGNR. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) with a one‐dimensional (1D), ribbon‐like structure have the potential to serve as both model compounds for corresponding graphene nanoribbons (GNRs) and as materials for optoelectronics applications. However, synthesizing molecules of this type with extended π‐conjugation presents a significant challenge. In this study, we present a straightforward synthetic method for a series of bis‐peri‐dinaphtho‐rylene molecules, wherein the peri‐positions of perylene, quaterrylene, and hexarylene are fused with naphtho‐units. These molecules were efficiently synthesized primarily through intramolecular or intermolecular radical coupling of in situ generated organic radical species. Their structures were confirmed using X‐ray crystallographic analysis, which also revealed a slightly bent geometry due to the incorporation of a cyclopentadiene ring at the bay regions of the rylene backbones. Bond lengh analysis and theoretical calculations indicate that their electronic structures resemble pyrenacenes more than quinoidal rylenes. That is, the aromatic sextets are predominantly localized along the long axis of the skeletones. As the chain length increases, these molecules exhibit enhanced electronic absorption with a bathochromic shift, and multiple amphoteric redox waves. This study introduces a novel synthetic approach for generating 1D extended PAHs and GNRs, along with their structure‐dependent electronic properties. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) with a one‐dimensional (1D), ribbon‐like structure have the potential to serve as both model compounds for corresponding graphene nanoribbons (GNRs) and as materials for optoelectronics applications. However, synthesizing molecules of this type with extended π‐conjugation presents a significant challenge. In this study, we present a straightforward synthetic method for a series of bis‐peri‐dinaphtho‐rylene molecules, wherein the peri‐positions of perylene, quaterrylene, and hexarylene are fused with naphtho‐units. These molecules were efficiently synthesized primarily through intramolecular or intermolecular radical coupling of in situ generated organic radical species. Their structures were confirmed using X‐ray crystallographic analysis, which also revealed a slightly bent geometry due to the incorporation of a cyclopentadiene ring at the bay regions of the rylene backbones. Bond lengh analysis and theoretical calculations indicate that their electronic structures resemble pyrenacenes more than quinoidal rylenes. That is, the aromatic sextets are predominantly localized along the long axis of the skeletones. As the chain length increases, these molecules exhibit enhanced electronic absorption with a bathochromic shift, and multiple amphoteric redox waves. This study introduces a novel synthetic approach for generating 1D extended PAHs and GNRs, along with their structure‐dependent electronic properties. [ABSTRACT FROM AUTHOR]

The aim is to tune the stability, as well as electronic and magnetic characteristics of zigzag α‐borophene nanoribbons (ZαBNRs) based on density functional theory. For this reason, the bare ZαBNR and its passivated edges by a single nitrogen atom (N‐ZαBNR) and also Mn‐ and Cr‐doped N‐ZαBNR is investigated. The results indicate that the nanoribbon becomes more stable by passivating the edges of the structure. Furthermore, the calculated electronic structures show that the Cr atom can remove the band gap of N‐ZαBNRs and turn it into metal. Besides, it can create magnetic properties in this structure. The Cr‐ and Mn‐doped N‐ZαBNR turn it into magnetic metal and diluted magnetic semiconductors, respectively. The results reveal a high Curie temperature of more than 700K for Cr‐ and Mn‐doped N‐ZαBNRs, indicating maybe good room‐temperature ferromagnetic material for spintronic applications in the future. [ABSTRACT FROM AUTHOR]

The physical and chemical properties of nanoribbon edges are important for characterizing nanoribbons and applying them in electronic devices, sensors, and catalysts. The mechanical response of molybdenum disulfide nanoribbons, which is an important issue for their application in thin resonators, is expected to be affected by the edge structure, albeit this result is not yet being reported. In this work, the width‐dependent Young's modulus is precisely measured in single‐layer molybdenum disulfide nanoribbons with armchair edges using the developed nanomechanical measurement based on a transmission electron microscope. The Young's modulus remains constant at ≈166 GPa above 3 nm width, but is inversely proportional to the width below 3 nm, suggesting a higher bond stiffness for the armchair edges. Supporting the experimental results, the density functional theory calculations show that buckling causes electron transfer from the Mo atoms at the edges to the S atoms on both sides to increase the Coulomb attraction. [ABSTRACT FROM AUTHOR]

Graphene nanoribbons (GNRs) are considered promising candidates for next‐generation nanoelectronics. In particular, GNR heterojunctions have received considerable attention due to their exotic topological electronic phases at the heterointerface. However, strategies for their precision synthesis remain at a nascent stage. Here, we report a novel chain‐growth polymerization strategy that allows for constructing GNR heterojunction with N=9 armchair and chevron GNRs segments (9‐AGNR/cGNR). The synthesis involves a controlled Suzuki–Miyaura catalyst‐transfer polymerization (SCTP) between 2‐(6′‐bromo‐4,4′′‐ditetradecyl‐[1,1′:2′,1′′‐terphenyl]‐3′‐yl) boronic ester (M1) and 2‐(7‐bromo‐9,12‐diphenyl‐10,11‐bis(4‐tetradecylphenyl)‐triphenylene‐2‐yl) boronic ester (M2), followed by the Scholl reaction of the obtained block copolymer (poly‐M1/M2) with controlled Mn (18 kDa) and narrow Đ (1.45). NMR and SEC analysis of poly‐M1/M2 confirm the successful block copolymerization. The solution‐mediated cyclodehydrogenation of poly‐M1/M2 toward 9‐AGNR/cGNR is unambiguously validated by FT‐IR, Raman, and UV/Vis spectroscopies. Moreover, we also demonstrate the on‐surface formation of pristine 9‐AGNR/cGNR from the unsubstituted copolymer precursor, which is unambiguously characterized by scanning tunneling microscopy (STM). [ABSTRACT FROM AUTHOR]

To date, precisely tailoring local active sites of well‐defined earth‐abundant metal‐free carbon‐based electrocatalysts for attractive electrocatalytic oxygen reduction reaction (ORR), remains challenging. Herein, the authors successfully introduce a strain effect on active C–C bonds adjacent to edged graphitic nitrogen (N), which raises appropriate spin‐polarization and charge density of carbon active sites and kinetically favor the facilitation of O2 adsorption and the activation of O‐containing intermediates. Thus, the constructed metal‐free carbon nanoribbons (CNRs‐C) with high‐curved edges exhibit outstanding ORR activity with half‐wave potentials of 0.78 and 0.9 V in 0.5 m H2SO4 and 0.1 m KOH, respectively, overwhelming the planar one (0.52 and 0.81 V) and the N‐doped carbon sheet (0.41 and 0.71 V). Especially in acidic media, the kinetic current density (Jk) is 18 times higher than that of the planar one and the N‐doped carbon sheet. Notably, these findings show the spin polarization of the asymmetric structure by introducing a strain effect on the C–C bonds for boosting ORR. [ABSTRACT FROM AUTHOR]

The problem of bag boundary conditions within a field‐theoretic approach is revisited to study confinement of massless Dirac quasispinors in monolayer graphene. While no‐flux bag boundaries have previously been used to model lattice termination sites in graphene nanoribbons, a generalized setting is considered in which the confining boundaries are envisaged as arbitrary straight lines drawn across a graphene sheet and the quasispinor currents are allowed to partially permeate (leak) through such boundaries. Specifically focus is on rectangular nanolanes defined as areas confined between a pair of parallel lines at arbitrary separation on an unbounded lattice. It is shown that such nanolanes exhibit a considerable range of bandgap tunability depending on their widths and armchair, zigzag, or intermediate orientation. The case of nanoribbons can be derived as a special limit from the nanolane model. In this case, certain inconsistencies are clarified in previous implementations of no‐flux bag boundaries and show that the continuum approach reproduces the tight‐binding bandgaps accurately (within just a few percent in relative deviation) even as the nanoribbon width is decreased to just a couple of lattice spacings. This accentuates the proper use of boundary conditions when field‐theoretic approaches are applied to graphene systems. [ABSTRACT FROM AUTHOR]

The incorporation of nanopores into graphene nanostructures has been demonstrated as an efficient tool in tuning their band gaps and electronic structures. However, precisely embedding the uniform nanopores into graphene nanoribbons (GNRs) at the atomic level remains underdeveloped especially for in‐solution synthesis due to the lack of efficient synthetic strategies. Herein we report the first case of solution‐synthesized porous GNR (pGNR) with a fully conjugated backbone via the efficient Scholl reaction of tailor‐made polyphenylene precursor (P1) bearing pre‐installed hexagonal nanopores. The resultant pGNR features periodic subnanometer pores with a uniform diameter of 0.6 nm and an adjacent‐pores‐distance of 1.7 nm. To solidify our design strategy, two porous model compounds (1 a, 1 b) containing the same pore size as the shortcuts of pGNR, are successfully synthesized. The chemical structure and photophysical properties of pGNR are investigated by various spectroscopic analyses. Notably, the embedded periodic nanopores largely reduce the π‐conjugation degree and alleviate the inter‐ribbon π–π interactions, compared to the nonporous GNRs with similar widths, affording pGNR with a notably enlarged band gap and enhanced liquid‐phase processability. [ABSTRACT FROM AUTHOR]

Discrete polymers offer an excellent platform for comprehending the interplay between precise chain structures, distinctive self‐assembly behavior, and functional applications, whereas the development of discrete polymers with self‐immolative properties remains scarce. Here, we modularly synthesize a library of discrete self‐immolative oligourethanes containing N‐naphthylcarbamate or N‐(3‐fluorophenyl)carbamate repeating units via iterative stepwise growth. These oligourethanes undergo not only cascade 1,6‐elimination depolymerizations via photo‐mediated removal of o‐nitrobenzyl carbamate triggers but also selective cleavage of benzyl‐O linkages under MS/MS conditions even without UV light irradiation. In aqueous media, these discrete oligourethanes self‐assemble into different morphologies such as flat nanosheets, nanofibers, and nanoribbons, depending on the chain lengths and backbone compositions, and further morphological transitions are observed upon thermal annealing. [ABSTRACT FROM AUTHOR]

Two novel N‐doped nonalternant nanoribbons (NNNR‐1 and NNNR‐2) featuring multiple fused N‐heterocycles and bulky solubilizing groups were prepared via bottom‐up solution synthesis. NNNR‐2 achieves a total molecular length of 33.8 Å, which represents the longest soluble N‐doped nonalternant nanoribbon reported to date. The pentagon subunits and doping of N atoms in NNNR‐1 and NNNR‐2 have successfully regulated their electronic properties, achieving high electron affinity and good chemical stability enabled by the nonalternant conjugation and electronic effects. When applied a laser pulse of 532 nm, the 13‐rings nanoribbon NNNR‐2 shows outstanding nonlinear optical (NLO) responses, with the nonlinear extinction coefficient of 374 cm GW−1, much higher than those of NNNR‐1 (96 cm GW−1) and the well‐known NLO material C60 (153 cm GW−1). Our findings indicate that the N‐doping of nonalternant nanoribbons is an effective strategy to access another type of excellent material system for high‐performance NLO applications, which can be extended to construct numerous heteroatom‐doped nonalternant nanoribbons with fine‐tunable electronic properties. [ABSTRACT FROM AUTHOR]

Two novel N‐doped nonalternant nanoribbons (NNNR‐1 and NNNR‐2) featuring multiple fused N‐heterocycles and bulky solubilizing groups were prepared via bottom‐up solution synthesis. NNNR‐2 achieves a total molecular length of 33.8 Å, which represents the longest soluble N‐doped nonalternant nanoribbon reported to date. The pentagon subunits and doping of N atoms in NNNR‐1 and NNNR‐2 have successfully regulated their electronic properties, achieving high electron affinity and good chemical stability enabled by the nonalternant conjugation and electronic effects. When applied a laser pulse of 532 nm, the 13‐rings nanoribbon NNNR‐2 shows outstanding nonlinear optical (NLO) responses, with the nonlinear extinction coefficient of 374 cm GW−1, much higher than those of NNNR‐1 (96 cm GW−1) and the well‐known NLO material C60 (153 cm GW−1). Our findings indicate that the N‐doping of nonalternant nanoribbons is an effective strategy to access another type of excellent material system for high‐performance NLO applications, which can be extended to construct numerous heteroatom‐doped nonalternant nanoribbons with fine‐tunable electronic properties. [ABSTRACT FROM AUTHOR]

Discrete polymers offer an excellent platform for comprehending the interplay between precise chain structures, distinctive self‐assembly behavior, and functional applications, whereas the development of discrete polymers with self‐immolative properties remains scarce. Here, we modularly synthesize a library of discrete self‐immolative oligourethanes containing N‐naphthylcarbamate or N‐(3‐fluorophenyl)carbamate repeating units via iterative stepwise growth. These oligourethanes undergo not only cascade 1,6‐elimination depolymerizations via photo‐mediated removal of o‐nitrobenzyl carbamate triggers but also selective cleavage of benzyl‐O linkages under MS/MS conditions even without UV light irradiation. In aqueous media, these discrete oligourethanes self‐assemble into different morphologies such as flat nanosheets, nanofibers, and nanoribbons, depending on the chain lengths and backbone compositions, and further morphological transitions are observed upon thermal annealing. [ABSTRACT FROM AUTHOR]

Silicene is a structure made of silicon atoms with a honeycomb hexagonal configuration. Silicene is not a flat structure like graphene, it has buckling. Silicene nanoribbons (SiNRs) are low‐dimensional structures built from silicene with chemically modified edges. The electronic properties of SiNRs also depend on the modification elements at the two edges. The antimony element will be doped in the SiNRs, and the electric field acting on the system is a constant electric field 0.3 V Å‐1. The configurations are stable after optimization by density function theory (DFT), and the energies of formation of the systems will also be calculated. The energy bands, states of the configurations will be plotted, analyzed, and compared. The structures after doping are all semi‐metallic, the band gap has disappeared. The partial states are also investigated, which depends on the density of particles per unit cell. [ABSTRACT FROM AUTHOR]

π‐Conjugated nanoribbons attract interest because of their unusual electronic structures and charge‐transport behavior. Here, we report the synthesis of a series of fully edge‐fused porphyrin‐anthracene oligomeric ribbons (dimer and trimer), together with a computational study of the corresponding infinite polymer. The porphyrin dimer and trimer were synthesized in high yield, via oxidative cyclodehydrogenation of singly linked precursors, using 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) and trifluoromethanesulfonic acid (TfOH). The crystal structure of the dimer shows that the central π‐system is flat, with a slight S‐shaped wave distortion at each porphyrin terminal. The extended π‐conjugation causes a dramatic red‐shift in the absorption spectra: the absorption maxima of the fused dimer and trimer appear at 1188 nm and 1642 nm, respectively (for the nickel complexes dissolved in toluene). The coordinated metal in the dimer was changed from Ni to Mg, using p‐tolylmagnesium bromide, providing access to free‐base and Zn complexes. These results open a versatile avenue to longer π‐conjugated nanoribbons with integrated metalloporphyrin units. [ABSTRACT FROM AUTHOR]

Layered quasi‐1D nanomaterials exhibit strong linear dichroism and effective light‐matter interactions, promising for novel information devices driven by light‐polarization. In particular, their optical anisotropy and ultrafast photoresponse allow for polarization‐controlled nanophotonic switches and modulators. However, the technology still requires substantial further studies due to an insufficient understanding of modulation mechanisms and limited investigations of a few materials. Here, transient absorption (TA) microscopy is employed to investigate the ultrafast polarization‐based optical switching in TiS3 nanoribbons, a rising quasi‐1D material of the transition metal trichalcogenide family. Highly anisotropic sub‐picosecond near‐infrared modulation is observed, which is most pronounced when the polarization of the probe pulse is aligned with the nanoribbon axis but disappears as the polarization is rotated to the perpendicular orientation. The authors attribute this significant dependence on the probe polarization to the hot carrier‐induced broadening of an anisotropic interband resonance, as supported by analyses of transient TA line shapes and first principles calculated optical transitions. Furthermore, a strong pump polarization‐dependent modulation is obtained by tuning the pumping energy, enabling highly anisotropic all‐optical switching controlled solely by polarization. These results offer comprehensive information on both probe‐ and pump‐polarization‐based modulations and a deeper physical understanding of polarization‐dependent photoresponse through ultrafast hot carrier dynamics. [ABSTRACT FROM AUTHOR]

π‐Conjugated nanoribbons attract interest because of their unusual electronic structures and charge‐transport behavior. Here, we report the synthesis of a series of fully edge‐fused porphyrin‐anthracene oligomeric ribbons (dimer and trimer), together with a computational study of the corresponding infinite polymer. The porphyrin dimer and trimer were synthesized in high yield, via oxidative cyclodehydrogenation of singly linked precursors, using 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) and trifluoromethanesulfonic acid (TfOH). The crystal structure of the dimer shows that the central π‐system is flat, with a slight S‐shaped wave distortion at each porphyrin terminal. The extended π‐conjugation causes a dramatic red‐shift in the absorption spectra: the absorption maxima of the fused dimer and trimer appear at 1188 nm and 1642 nm, respectively (for the nickel complexes dissolved in toluene). The coordinated metal in the dimer was changed from Ni to Mg, using p‐tolylmagnesium bromide, providing access to free‐base and Zn complexes. These results open a versatile avenue to longer π‐conjugated nanoribbons with integrated metalloporphyrin units. [ABSTRACT FROM AUTHOR]

Graphene nanoribbons are thin sheets of graphene showing exclusive characteristics such as better drug‐loading capacity, adsorption on mammalian cells, greater surface area, and light‐absorbing ability. The current research work is to develop metformin‐adsorbed carboxyl‐functionalized oxidized graphene nanoribbons and utilize drug repurposing for the treatment of oral cancer by activating photo‐thermal radiation therapy. The nanoribbons are formulated by Hummer's method and evaluated for several characterization parameters like ATR‐ Fourier Transform Infrared (FTIR), Differential scanning calorimetry (DSC), topology, in vitro efficacy, ex vivo and in vitro cell line studies. The ATR‐FTIR spectrum of formulated nanoribbons shows distinctive peak at 3370 cm−1 (NH group) of metformin. The DSC specifies the incidence of steep endothermic crests at 235 °C (CNH3). The in vitro and ex vivo drug release studies show enhanced drug release in acidic pH (6.4) than physiological pH (7.4) with photothermal radiation. The in vitro cell line studies are processed via two‐way ANOVA that exhibits 67.74 ± 0.03% of % inhibition in presence of photothermal radiation. The study demonstrates higher inhibition of cancerous cells at lower concentration of drug and photothermal therapy in comparison to plain drug. The characteristic feature of graphene is used to develop targeted drug delivery system against the oral cancerous cells. [ABSTRACT FROM AUTHOR]

Graphene nanoribbons (GNRs) and nanographenes synthesized by on‐surface reactions using tailor‐made molecular precursors offer an ideal playground for a study of magnetism towards nano‐spintronics. Although the zigzag edge of GNRs has been known to host magnetism, the underlying metal substrates usually veil the edge‐induced Kondo effect. Here, we report the on‐surface synthesis of unprecedented, π‐extended 7‐armchair GNRs using 7‐bromo‐12‐(10‐bromoanthracen‐9‐yl)tetraphene as the precursor. Characterization by scanning tunneling microscopy/spectroscopy revealed unique rearrangement reactions leading to pentagon‐ or pentagon/heptagon‐incorporated, nonplanar zigzag termini, which demonstrated Kondo resonances even on bare Au(111). Density functional theory calculations indicate that the nonplanar structure significantly reduces the interaction between the zigzag terminus and the Au(111) surface, leading to a recovery of the spin localization of the zigzag edge. Such a distortion of planar GNR structures offers a degree of freedom to control the magnetism on metal substrates. [ABSTRACT FROM AUTHOR]

Graphene nanoribbons (GNRs) and nanographenes synthesized by on‐surface reactions using tailor‐made molecular precursors offer an ideal playground for a study of magnetism towards nano‐spintronics. Although the zigzag edge of GNRs has been known to host magnetism, the underlying metal substrates usually veil the edge‐induced Kondo effect. Here, we report the on‐surface synthesis of unprecedented, π‐extended 7‐armchair GNRs using 7‐bromo‐12‐(10‐bromoanthracen‐9‐yl)tetraphene as the precursor. Characterization by scanning tunneling microscopy/spectroscopy revealed unique rearrangement reactions leading to pentagon‐ or pentagon/heptagon‐incorporated, nonplanar zigzag termini, which demonstrated Kondo resonances even on bare Au(111). Density functional theory calculations indicate that the nonplanar structure significantly reduces the interaction between the zigzag terminus and the Au(111) surface, leading to a recovery of the spin localization of the zigzag edge. Such a distortion of planar GNR structures offers a degree of freedom to control the magnetism on metal substrates. [ABSTRACT FROM AUTHOR]

Graphene nanoribbons (GNRs) are emerging materials inheriting excellent properties from graphene while potentially exhibiting semiconducting behavior. All these features sparked numerous efforts to insert GNRs in nanoelectronics. As a result, synthesis routes with atomic resolution are now a reality. Recently, the rise of heterojunction (HJ) engineering pushed even further the prospects, allowing the blending of different GNRs as building blocks. However, much of the potential behind it remains untouched for some junctions. In this work, the consequences of forming a cove‐type GNR (CGNR) HJ by assembling specimens with borders of different zig‐zag/armchair ratios are explored. The nanoribbons are simulated using the extended two‐dimensional Su–Schrieffer–Heeger model with electron–phonon coupling. The findings show that manipulating the junction creates multiple routes for smooth monotonic gap tuning. Moreover, the changes in the hopping mechanism, mobility, and effective mass are reported leading to variations up to 10 000 cm2 V−1 s−1 and 0.425 me. This work reveals a pathway to expand the modularity of CGNRs through smooth control of the charge carrier's properties. Future applications can explore this feature to design devices with highly specific charge transport characteristics. The study also serves as theoretical background, potentially inspiring new tuning strategies in other GNRs. [ABSTRACT FROM AUTHOR]

Electrochemical two‐electron oxygen reduction reaction (2 e− ORR) to produce hydrogen peroxide (H2O2) is a promising alternative to the energetically intensive anthraquinone process. However, there remain challenges in designing 2 e− ORR catalysts that meet the application criteria. Here, we successfully adopt a microwave‐assisted mechanochemical‐thermal approach to synthesize hexagonal phase SnO2 (h‐SnO2) nanoribbons with largely exposed edge structures. In 0.1 M Na2SO4 electrolyte, the h‐SnO2 catalysts achieve the excellent H2O2 selectivity of 99.99 %. Moreover, when employed as the catalyst in flow cell devices, they exhibit a high yield of 3885.26 mmol g−1 h−1. The enhanced catalytic performance is attributed to the special crystal structure and morphology, resulting in abundantly exposed edge active sites to convert O2 to H2O2, which is confirmed by density functional theory calculations. [ABSTRACT FROM AUTHOR]

Electrochemical two‐electron oxygen reduction reaction (2 e− ORR) to produce hydrogen peroxide (H2O2) is a promising alternative to the energetically intensive anthraquinone process. However, there remain challenges in designing 2 e− ORR catalysts that meet the application criteria. Here, we successfully adopt a microwave‐assisted mechanochemical‐thermal approach to synthesize hexagonal phase SnO2 (h‐SnO2) nanoribbons with largely exposed edge structures. In 0.1 M Na2SO4 electrolyte, the h‐SnO2 catalysts achieve the excellent H2O2 selectivity of 99.99 %. Moreover, when employed as the catalyst in flow cell devices, they exhibit a high yield of 3885.26 mmol g−1 h−1. The enhanced catalytic performance is attributed to the special crystal structure and morphology, resulting in abundantly exposed edge active sites to convert O2 to H2O2, which is confirmed by density functional theory calculations. [ABSTRACT FROM AUTHOR]

In the present work, the relativistic quantum motion of massless fermions in a helicoidal graphene nanoribbon under the influence of a uniform magnetic field is investigated. Considering a uniform magnetic field (B) aligned along the axis of helicoid, this problem is explored in the context of Dirac equation in a curved space‐time. As this system does not support exact solutions due to considered background, the bound‐state solutions and local density of states (LDOS) are obtained numerically by means of the Numerov method. The combined effects of width of the nanoribbon (D), length of ribbon (L), twist parameter (ω), and B on the equations of motion and LDOS are analyzed and discussed. It is verified that the presence of B produces a constant minimum value of local density of state on the axis of helicoid, which is possible only for values large enough of ω, in contrast to the case for B=0$B=0$ already studied in the literature. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) are widely utilized in sensing, energy storage, and catalysis due to their excellent optical, electrical and semiconducting properties. However, attempts to optimize their optoelectronic performance through high‐order manipulation have met with little success to date. In this study, through efficient packing of individual CDs in two‐dimensions, the synthesis of flexible CDs ribbons is demonstrated technically. Electron microscopies and molecular dynamics simulations, show the assembly of CDs into ribbons results from the tripartite balance of π–π attractions, hydrogen bonding, and halogen bonding forces provided by the superficial ligands. The obtained ribbons are flexible and show excellent stability against UV irradiation and heating. CDs ribbons offer outstanding performance as active layer material in transparent flexible memristors, with the developed devices providing excellent data storage, retention capabilities, and fast optoelectronic responses. A memristor device with a thickness of 8 µm shows good data retention capability even after 104 cycles of bending. Furthermore, the device functions effectively as a neuromorphic computing system with integrated storage and computation capabilities, with the response speed of the device being less than 5.5 ns. These properties create an optoelectronic memristor with rapid Chinese character learning capability. This work lays the foundation for wearable artificial intelligence. [ABSTRACT FROM AUTHOR]

The construction of efficient non‐precious metal electrocatalysts for oxygen reduction reaction (ORR) with controlled structures and active sites is of fundamental importance for the wide utilization of hydrogen fuel cells. Herein, we report a controllable chemical fixation strategy that enables the simultaneous optimization in both of local and external structure of the Fe−N−C catalyst. The post‐synthetic single‐atomic chemical fixation of Fe2+ ions in coordinated‐free bi‐pyridine sites combined with the carbonation afford a Fe2N‐embedded N‐doped graphene nanoribbon (Fe2N/NGNR) with dispersing Fe2N nanoparticles embedded in NGNR. When used as ORR electrocatalyst, Fe2N/NGNR exhibits a half‐wave potential of 0.87 V and 0.79 V vs. RHE in alkaline and acid medium, respectively, comparable to commercial Pt/C (20 wt%) catalysts. The prominent ORR activity of Fe2N/NGNR is verified an H2‐O2 fuel cell which displayed a peak power density of 307.7 mW/cm2 when using the Fe2N/NGNR as the catalyst in the cathode electrode. [ABSTRACT FROM AUTHOR]