Hybrid Nanoribbons Research Articles

Faujasite/graphene nanoribbon hybrid adsorbent pellet for carbon dioxide capture

Pelletizing zeolite adsorbents is essential for practical applications, but conventional pelletization methods involve binders that can alter material properties. This study presents a one-pot approach to synthesizing FAU-type zeolite/graphene oxide nanoribbon (GONR) composite powders that can be pelletized by simple pressing without binders. This one-pot synthesis can be conducted without structure-directing agents, making the process simpler and more efficient. During zeolite crystallization, the particles decorate the strands of GONRs, effectively generating additional macropores and enhancing the pellets’ mechanical strength. Additionally, GONR suppresses water adsorption while maintaining good CO₂ adsorption, which improves the material’s performance under humid conditions. The FAU/GONR pellets exhibited enhanced mass transport properties compared to neat FAU pellets, as demonstrated by 10 times higher CO₂ permeability. The highest CO₂/N₂ selectivity of 76.5 was observed with 12 wt% GONR-containing pellet, and the performance was comparable to conventional pellets, while the fabrication procedure remained simple.

Effective theory for graphene nanoribbons with junctions

Graphene nanoribbons are a promising candidate for fault-tolerant quantum electronics. In this scenario, qubits are realized by localized states that can emerge on junctions in hybrid ribbons formed by two armchair nanoribbons of different widths. We derive an effective theory based on a tight-binding ansatz for the description of hybrid nanoribbons and use it to make accurate predictions of the energy gap and nature of the localization in various hybrid nanoribbon geometries. We use quantum Monte Carlo simulations to demonstrate that the effective theory remains applicable in the presence of Hubbard interactions. We discover, in addition to the well-known localizations on junctions, which we call “Fuji”, a new type of “Kilimanjaro” localization smeared out over a segment of the hybrid ribbon. We show that Fuji localizations in hybrids of width N and N+2 armchair nanoribbons occur around symmetric junctions if and only if N(mod3)=1, while edge-aligned junctions never support strong localization. This behavior cannot be explained relying purely on the topological Z2 invariant, which has been believed to be the origin of the localizations to date. Published by the American Physical Society 2024

Highly Sensitive Weaving Sensor of Hybrid Graphene Nanoribbons and Carbon Nanotubes for Enhanced Pressure Sensing Function.

Carbon nanotubes (CNTs) hold great promise in next-generation sensors because of their remarkable physical properties. Yet, maintaining precise stacking configurations of CNTs to make full use of their remarkable properties is challenging because of their susceptibility to spontaneous reconstruction. Inspired by the weaving technology, we propose a CNT-graphene nanoribbon hybrid woven model that can maintain the specific structure of CNTs to achieve their elaborately designed function. In this study, comprehensive molecular dynamics simulations are carried out to investigate the thermal stability of the CNT-graphene hybrid woven model, as well as their potential for pressure sensing applications by utilizing the unique response of thermal transport to mechanical deformation at heterojunctions. The thermal stability is sensitive to the size of the graphene nanoribbon, and the woven structure remains stable from 200-500 K when its width is greater than 2.0 nm. Moreover, it is exciting that the sensors are effective at predicting the shapes of externally loaded objects through the analysis of the thermal conductivity distribution, which can be derived from the relationship between the thermal conduction and the pressure. Our findings shed light on the bottom-up functional design of nanomaterials and expand wider applications of high-performance nanosensors in other related fields.

Boron-rich hybrid BCN nanoribbons for highly ambient uptake of H2S, HF, NH3, CO, CO2 toxic gases.

Nanomaterials-based gas sensors are widely applied for the monitoring and fast detection of hazardous gases owing to their sensitivity and selectivity. Hydrogen sulfide (H2S), hydrogen fluoride (HF), ammonia (NH3), and carbon monoxide/dioxide (CO/CO2) produced from petroleum fields, sewage, mines, and gasoline are harmful for both human life and environment. With an increase in the emission of these toxic compounds, their real-time monitoring and efficient adsorbent application and storage are very necessary. To this end, we investigated the adsorption characteristic and sensitivity factor of these five toxic gases on armchair and zigzag hybrid boron-carbon-nitride (BCN) nanoribbons with/without boron-rich (B-rich) defects using first principle calculation, where 25%, 33%, and 50% carbon concentration were considered. Our findings reveal that B-rich nanoribbons have strong adsorption energy, charge transfer, and structural deformation owing to the double acceptor of B-rich defects. Moreover, the zigzag and armchair forms of these hybrid BCN nanoribbons show physical adsorption, altering their band gap and phase transition after adsorbing these toxic gases, where B-rich nanoribbons possess high sensitivity to NH3 and CO among other gases. Furthermore, B-rich hybrid nanoribbons have higher CO2 adsorption energy than the standard free energy of CO2 at room temperature. This study suggests that hybrid BCN nanoribbons and B-rich defected structures can be good candidates for the uptake and storage of toxic gases, helping experimental groups to design efficient ambient gas sensors.

Role of 1D edge in the elasticity and fracture of h-BN doped graphene nanoribbons

Recent achievement of BN-graphene alloy material has enabled the potential of bandgap tuning through both sub-10 nm width control and BN concentration variation. However, its mechanics, which is necessary for prediction of stability in functional applications, is not well studied. Here, molecular dynamics simulation is performed to conduct uniaxial tensile test for BN-doped graphene nanoribbons (BN-GNR) with varying widths and BN atom fractions. Efforts are made to study the constitutive relations for the edges and the whole BN-GNR and explore the fracture mechanisms of the hybrid nanoribbons. The substantial softening effect of the edges induced by wrinkling alters the impact of BN concentration on the stiffness in the sub-20 nm regime deviating from the linear behaviour observed in the bulk case. Fracture properties are unexpectedly independent of BN concentrations unlike in the bulk and the failure behaviour is rather decided by the graphene ribbon edge structure. Here the armchair edges serve as the source of crack nucleation at an early stage leading to weakened strength and reduced stretchability, whereas zigzag edges do not promote early crack nucleation and leads to the size dependence of fracture properties.

In situ constructing heterogeneous Mn(VO3)2/NaVO3 nanoribbons as high-performance cathodes for aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) are emerging as a promising candidate, enjoying accolades for their safety, low cost, and ease of operation. However, some challenges like the slow kinetics and structural collapse of cathode materials hamper their rate capability and cyclability. To address these limitations, a heterogeneous Mn(VO3)2/NaVO3 (MNVO) nanoribbon hybrid was designed as high-performance cathodes for zinc storage. Owing to the heterointerface between Mn(VO3)2 and NaVO3 boosting the charge-transfer kinetics and leading to enhanced zinc diffusion kinetics, the MNVO exhibits a high specific capacity of 381.2 mAh g−1 at 0.2 A g−1, high rate capability (286.7 mAh g−1 at 5 A g−1), and excellent electrochemical kinetics. Additionally, the MNVO cathode exhibits stable cyclability (a high-capacity retention rate of 95.7% at 1 A g−1 after 200 cycles) and excellent long-term cyclability (a high-capacity retention of 83.0% after 2000 cycles). Moreover, the zinc storage mechanism of co-intercalation of Zn2+ and H2O into the host of MNVO were investigated by ex situ XRD and XPS characterizations. Our work offers new insight and understanding into the development of high-performance cathode materials through constructing heterogeneous structure.

Apparent symmetry rising induced by crystallization inhibition in ternary co-crystallization-driven self-assembly

The concept of apparent symmetry rising, opposite to symmetry breaking, was proposed to illustrate the unusual phenomenon that the symmetry of the apparent morphology of the multiply twinned particle is higher than that of its crystal structure. We developed a unique strategy of co-crystallization-driven self-assembly of amphiphilic block copolymers PEO-b-PS and the inorganic cluster silicotungstic acid to achieve apparent symmetry rising of nanoparticles under mild conditions. The triangular nanoplates triply twinned by orthogonal crystals (low symmetry) have an additional triple symmetry (high symmetry). The appropriate crystallization inhibition of short solvophilic segments of the block copolymers favors the oriented attachment of homogeneous domains of hybrid nanoribbons, and consequently forms kinetic-controlled triangular nanoplates with twin grain boundaries.

Tunable spin and conductance in porphyrin-graphene nanoribbon hybrids

Recently, porphyrin units have been attached to graphene nanoribbons (Por-GNR) enabling a multitude of structures. Here we report first-principles calculations of two prototypical, experimentally feasible, Por-GNR hybrids, one of which displays a small band gap relevant as electrodes in devices. Embedding a Fe atom in the porphyrin causes spin-polarized ground state (S = 1). Using density functional theory and nonequilibrium Green’s function, we examine a 2-terminal setup involving a Fe-Por-GNR between small band gap, Por-GNR electrodes. The coupling between the Fe-d and GNR band states results in a Fano anti-resonance feature in the spin transport, making the conductance highly sensitive to the Fe spin state. We demonstrate how mechanical strain or chemical adsorption on the Fe give rise to spin-crossover to S = 2 and S = 0, directly reflected in the transmission. Our results provide a deep understanding which can open an avenue for carbon-based spintronics and chemical sensing.

Manipulating topological intravalley and intervalley scatterings of inner edge states in hybrid nanoribbons

We investigate the formation of inner edge states and their transport properties in hybrid nanoribbons. Some new inner edge states, such as spin-polarized, spin-valley-polarized and valley-polarized antichiral inner edge states, are obtained, different from the current existence of valley- and spin-valley-momentum locked inner edge states. We also obtain general formula of local bond current with the wave-function matching technique and use it to discover three interesting transport phenomena of the intravalley and intervalley scatterings that depend on the propagating direction, propagating path, spin mode and wave-vector mismatches between inner edge states. In particular, these transport phenomena are further used to design topological spin, spin–valley and valley filters and be representative for graphene, silicene, germanene and stanene, supporting a potential application of inner edge states, which are robust against random vacancies.

Localization of electronic states in hybrid nanoribbons in the nonperturbative regime

We investigate the localization of low-energy single quasi-particle states in the 7/9-hybrid nanoribbon system in the presence of strong interactions and within a finite volume. We consider two scenarios, the first being the Hubbard model at half-filling and perform quantum Monte Carlo simulations for a range $U$ that includes the strongly correlated regime. In the second case we add a nearest-neighbor superconducting pairing $\Delta$ and take the symmetric line limit, where $\Delta$ is equal in magnitude to the hopping parameter $t$. In this limit the quasi-particle spectrum and wavefunctions can be directly solved for general onsite interaction $U$. In both cases we extract the site-dependent quasi-particle wavefunction densities and demonstrate that localization persists in these non-perturbative regimes under particular scenarios.

On-Surface Synthesis of Rigid Benzenoid- and Nonbenzenoid-Coupled Porphyrin–Graphene Nanoribbon Hybrids

On-Surface Synthesis of Rigid Benzenoid- and Nonbenzenoid-Coupled Porphyrin–Graphene Nanoribbon Hybrids

Electronic and thermodynamic properties of zigzag MoS2/ MoSe2 and MoS2/ WSe2 hybrid nanoribbons: Impacts of electric and exchange fields

Using the tight-binding approach and non-equilibrium Green’s function method, we investigate the electronic band structure, total electronic heat capacity (EHC), and Pauli spin susceptibility (PSS) of zigzag MoS2/MoSe2 and MoS2/WSe2 hybrid nanoribbons in the presence of transverse electric and external exchange fields. Our results show that in the simultaneous presence of both of these fields, the zigzag MoS2/WSe2 and MoS2/MoSe2 nanoribbons are converted to half-metal systems. The total EHC increases with growing temperature until the Schottky anomaly appears at 150 K. we show that these hybrid nanoribbons become almost antiferromagnetic with the Neel temperature of 200 K. Interestingly, in the whole range temperature, the total EHC and PSS decrease by the transverse electric and external exchange fields. Our results provide an efficient and practical approach to the design of spintronic devices.

(Invited) Porphyrinoid-Carbon Nanostructure Ensembles

The development of new chromophoric receptors able to bind curved carbon nanostructures is at the epicenter of the quest for fullerene-based organic photovoltaics with improved performances. Herein, a subphthalocyanine-based multicomponent ensemble consisting of two electron-rich SubPc-monomers rigidly attached to the convex surface of a electron-poor SubPc-dimer has been synthesized and characterized. Such a unique conformation, especialy in terms of the two SubPc-monomers, together with the overall stiffness of the tether endows the multicomponent system with a well-defined tweezer-like topology to efficiently embrace a fullerene in its inner cavity. On the other hand, the selective on-surface synthesis of a porphyrin-graphene nanoribbon hybrid has been accomplished. The atomically precise structure of the hybrid has been unambiguously characterized by bond-resolved scanning tunneling microscopy and noncontact atomic force microscopy. Finally, a novel electron donor-acceptor hybrid consisting of a NIR absorbing azulenocyanine as electron donor and few-layer graphene as electron acceptor was prepared. The extended aromatic core of azulenocyanine assist in the exfoliation of graphite and allows formation of a very high-quality few-layer graphene azulenocyanine hybrid system.

(Invited) Covalent and Supramolecular Multicomponent Porphyrinoid-Carbon Nanostructure Ensembles

Herein, a novel electron donor-acceptor hybrid consisting of a NIR absorbing azulenocyanine as electron donor and few-layer graphene as electron acceptor was prepared. The extended aromatic core of azulenocyanine assist in the exfoliation of graphite and allows formation of a very high-quality few-layer graphene azulenocyanine hybrid system. The development of new chromophoric receptors able to bind curved carbon nanostructures is at the epicenter of the quest for fullerene-based organic photovoltaics with improved performances. Herein, a subphthalocyanine-based multicomponent ensemble consisting of two electron-rich SubPc-monomers rigidly attached to the convex surface of a electron-poor SubPc-dimer has been synthesized and characterized. Such a unique conformation, especialy in terms of the two SubPc-monomers, together with the overall stiffness of the tether endows the multicomponent system with a well-defined tweezer-like topology to efficiently embrace a fullerene in its inner cavity. The selective on-surface synthesis of a porphyrin-graphene nanoribbon hybrid has been accomplished. The atomically precise structure of the hybrid has been unambiguously characterized by bond-resolved scanning tunneling microscopy and noncontact atomic force microscopy.

Performance of a Novel 3D Graphene–WS2 Hybrid Structure for Sodium-Ion Batteries

Three dimensional (3D) heterostructure materials display proper energy storage performance and high electric conductivity. In this work, the application of 3D graphene sheets and zigzag WS2 nanoribbon (3DGW) hybrid structures as anode materials for sodium-ion batteries is studied on the basis of first-principle calculations. Compared with related single-layer nanosheets and nanoribbon hybrid components, 3DGW heterostructures show an enhanced Na adsorption interaction and good electrical conductivity, which competes with popular electrode materials for sodium-ion batteries. The activation barrier for Na diffusion in 3DGW hybrid structures is lower than in two dimensional hybrid components, which can expect higher cycling rates. Our results present the performance of a new 3D material for next-generation sodium-ion electrode materials and provide proper insight into exploring high-capacity 3D heterostructure materials for battery applications.

Uniform hybrid nanoribbons from unidirectional inclusion crystallization controlled by size-amphiphilic block copolymers.

Herein, we suggest a unique approach to control the growth of hybrid crystals of silicotungstic acid (STA) by introducing a poly(ethylene oxide) (PEO)-containing block copolymer and a poly(methyl methacrylate)-b-poly(ethylene oxide)-b-poly(methyl methacrylate) block copolymer (MEM BCP). Remarkably, perfectly straight ribbon-like lamellae with a uniform width and a large length/width ratio (>200) can be obtained. The length of hybrid nanoribbons can be tuned by annealing time and temperature, whereas the width is dependent on the molecular weight of the PEO mid-block. The stability of hybrid nanoribbons has been investigated against solvent vapor, high temperatures and the presence of phosphotungstic acid (PTA). The formation of hybrid nanoribbons leads to enhanced mechanical properties and proton conductivities of STA hybrid nanocomposites. This effective approach will provide a representative strategy to the control of crystalline hybrid materials in the solid state.

Inside Back Cover: On‐Surface Synthesis and Characterization of Triply Fused Porphyrin–Graphene Nanoribbon Hybrids (Angew. Chem. Int. Ed. 3/2020)

Inside Back Cover: On‐Surface Synthesis and Characterization of Triply Fused Porphyrin–Graphene Nanoribbon Hybrids (Angew. Chem. Int. Ed. 3/2020)

On‐Surface Synthesis and Characterization of Triply Fused Porphyrin–Graphene Nanoribbon Hybrids

AbstractOn‐surface synthesis offers a versatile approach to prepare novel carbon‐based nanostructures that cannot be obtained by conventional solution chemistry. Graphene nanoribbons (GNRs) have potential for a variety of applications. A key issue for their application in molecular electronics is in the fine‐tuning of their electronic properties through structural modifications, such as heteroatom doping or the incorporation of non‐benzenoid rings. In this context, the covalent fusion of GNRs and porphyrins (Pors) is a highly appealing strategy. Herein we present the selective on‐surface synthesis of a Por–GNR hybrid, which consists of two Pors connected by a short GNR segment. The atomically precise structure of the Por–GNR hybrid has been characterized by bond‐resolved scanning tunneling microscopy (STM) and noncontact atomic force microscopy (nc‐AFM). The electronic properties have been investigated by scanning tunneling spectroscopy (STS), in combination with DFT calculations, which reveals a low electronic gap of 0.4 eV.

On‐Surface Synthesis and Characterization of Triply Fused Porphyrin–Graphene Nanoribbon Hybrids

On-surface synthesis offers a versatile approach to prepare novel carbon-based nanostructures that cannot be obtained by conventional solution chemistry. Graphene nanoribbons (GNRs) have potential for a variety of applications. A key issue for their application in molecular electronics is in the fine-tuning of their electronic properties through structural modifications, such as heteroatom doping or the incorporation of non-benzenoid rings. In this context, the covalent fusion of GNRs and porphyrins (Pors) is a highly appealing strategy. Herein we present the selective on-surface synthesis of a Por-GNR hybrid, which consists of two Pors connected by a short GNR segment. The atomically precise structure of the Por-GNR hybrid has been characterized by bond-resolved scanning tunneling microscopy (STM) and noncontact atomic force microscopy (nc-AFM). The electronic properties have been investigated by scanning tunneling spectroscopy (STS), in combination with DFT calculations, which reveals a low electronic gap of 0.4 eV.

Laser-induced bi-metal sulfide/graphene nanoribbon hybrid frameworks for high-performance all-in-one fiber supercapacitors

High-performance yet flexible all-in-one fiber supercapacitors (FSCs) hold a great potential in powering the next-generation wearable/portable electronics. Rational design and scalable construction of unique three-dimensional structures are challenging for assembling these types of FSCs. Here, we demonstrate a unique laser-induced bi-metal sulfide/graphene nanoribbon (GR) hybrid framework for high-performance all-in-one flexible FSCs. The bi-metal sulfide/GR hybrid framework performs a superior electrochemical performance to both of GR and single-metal sulfide/GR hybrid frameworks. In addition, the as-assembled all-in-one flexible FSCs based on laser-induced molybdenum disulfide/manganese sulfide/GR (MoS2/MnS/GR) hybrid frameworks exhibit a high areal specific capacitance of 58.3 mF/cm2 at 50 μA/cm2, a high areal energy density of 7.0 μWh/cm2 at 50 μA/cm2, a high areal power density of 49.9 μW/cm2 at 50 μA/cm2, as well as a high cycling stability (93.6%, 10000 cycles). It's proposed that the synergistic effects of bi-metal sulfide as well as the unique laser-induced three-dimensional frameworks account for the excellent electrochemical performances of the as-designed framework electrodes. The concept of designing this laser-induced three-dimensional hybrid structure based on bi-metallic pseudocapacitive material and capacitive GR can provide an insight for assembling high-performance flexible fiber supercapacitors and show promising for integrating and powering portable and wearable electronics.