Hydrogen-substituted Graphdiyne Research Articles

Interfacial [S─Cu─C] Bonds Induced π-d Electron Coupling Toward Modulating Charge Transfer for Efficient Solar Water Oxidation.

Regulating the interfacial electric field to achieve rapid charge transfer is crucial for superior photoelectrochemical water splitting. Herein, the ultra-thin hydrogen-substituted graphdiyne (HsGDY) is precisely assembled on the surface of CdS nanorod array (Cu-CdS-HsGDY) by an in situ polymerization strategy. The strong π-d electron coupling is aroused by the delocalized π electrons of HsGDY and the delocalized d electrons of CdS through the interfacial [S─Cu─C] bonds. The strong interfacial electric field can effectively promote the charge localization distribution and reduce the charge transfer resistance. The optimized Cu-CdS-HsGDY photoanode obtain a photocurrent density as high as 4.83 mA cm-2 at 1.23 V versus reversible hydrogen electrode in neutral electrolyte solution under AM 1.5G illumination, which is 6.8 times that of the pristine CdS. Moreover, the photoanode maintains an initial photocurrent density of 84% within 4 h without any assistance of sacrificial agents, which is a rather competitive performance of similar sulfide photoanodes. The mechanism of strong π-d electron coupling on interfacial charge transfer and surface reaction kinetics is investigated by transient spectroscopy measurements, density functional theory calculation, and finite element simulation analysis. This work provides new insights into designing a reasonable interface structure to regulate charge transfer for achieve efficient PEC water splitting.

Bio-inspired carbon-based artificial muscle with precise and continuous morphing capabilities

Abstract In the face of advancements in micro-robotics, intelligent control, and precision medicine, artificial muscle actuation systems must meet demands for precise control, high stability, environmental adaptability, and high integration miniaturization. Carbon materials, with their lightweight, high strength, conductivity, and flexibility, show great potential for artificial muscles. Inspired by the butterfly's proboscis, we have developed a carbon-based artificial muscle, HsGDY-M, fabricated efficiently using an emerging hydrogen-substituted graphdiyne (HsGDY) film with an asymmetrical surface structure. This muscle features reversible, rapid, and continuously adjustable deformation capabilities similar to the butterfly's proboscis, triggered by the conversion of carbon bonds. The size of the HsGDY-M can be tuned by tailoring the HsGDY film width from ∼1 cm to 100 µm. Our research demonstrates HsGDY-M's stability and adaptability, maintaining performance at temperatures as low as -25°C. This artificial muscle was successfully integrated into a robotic mechanical arm, allowing it to swiftly adjust its posture and lift objects up to 11 times its own weight. Its beneficial responsiveness is transferable, enabling the transformation of “inert” objects like copper foil into actuators via surface bonding. Since its super sensitive and rapid deformation, HsGDY-M was applied to create a real-time tracking system for human finger bending movements, achieving real-time simulation and large-hand-to-small-hand control. Our study indicates that HsGDY-M holds significant promise for advancing smart robotics and precision medicine.

Enhanced charge transfer through defect and doping synergistic engineering for efficient hydrogen production

Simultaneous modification of catalysts by surface defects and atomic doping strategies can effectively inhibit the recombination of photogenerated carriers. In this study, the surface state of MoS2 was adjusted through the synergistic effects of sulfur defects and the doping of oxygen atoms, successfully constructing a type II heterojunction with hydrogen-substituted graphdiyne (H-GDY) for efficient photocatalytic hydrogen generation. The results showed that the H-GDY/O-MoS2-x exhibits the best hydrogen production performance (2272.97 μmol/g/h), which is about 25 times that of MoS2. And the synergistic effect of sulfur defects and oxygen doping engineering can modulate the energy band structure and increase the interfacial potential difference between H-GDY and O-MoS2-x, which enhances the driving force of electron transfer and improves the interfacial charge transfer and separation efficiency. This work shows that the synergistic effect of defect and doping engineering can effectively improve the photocatalytic performance and provides a new idea for the preparation of sulfide-based photocatalysts.

Thickness-controlled HsGDY/N-doped double-shell hollow carbon tubes for broadband high-performance microwave absorption

With the increasing deterioration of the electromagnetic environment, it is important to develop new and efficient electromagnetic wave-absorbing materials. In this work, bilayer hollow HsGDY/NC nanotubes with controllable thickness are constructed by introducing high conductivity polydopamine (PDA) and hydrogen-substituted graphdiyne (HsGDY) followed by the etching and carbonization. Subsequently, the effects of the composition, coating order, and structural characteristics of nanotubes on the electromagnetic parameters are thoroughly investigated, thereby analyzing the microwave absorption mechanism. The impedance matching of HsGDY/NC is optimized by changing the thickness of NC layer, while utilizing unique multi-heterogeneous interfaces and hierarchical conductive structures that enhance the interface polarization and conductive loss. As a result, HsGDY@NC-3 displays the optimal absorbing performance with an effective absorption bandwidth (EAB) of 7.8 GHz (10.1–17.9 GHz) and a minimum reflection loss (RLmin) of −47.18 dB at the filler content of only 11 %. This work broadens the application scopes of HsGDY and provides a novel insight into the design of lightweight, high-efficiency, and wide-frequency microwave absorbers, which is expected to be a potentially effective microwave-absorbing material.

Hydrogen-Substituted Graphdiyne Encapsulated Cu2O Nanowires as Binder-Free Electrodes for Non-Enzymatic Glucose Sensing

Hydrogen-Substituted Graphdiyne Encapsulated Cu₂O Nanowires as Binder-Free Electrodes for Non-Enzymatic Glucose Sensing

Conducting Paper Based on Few-Layered Hydrogen-Substituted Graphdiyne for Swine Flu Detection

Conducting Paper Based on Few-Layered Hydrogen-Substituted Graphdiyne for Swine Flu Detection

Strong interface coupling of H-substituted graphdiyne-based promotes photocatalytic hydrogen production

As an advanced material, graphdiyne (GDY) is expected to be an ideal platform for photocatalytic reactions due to its large π-conjugated structure on the surface, rich sp-C triple-bond skeleton with catalytic activity, and high carrier mobility. However, the electronic configuration of graphdiyne makes it difficult to achieve efficient interfacial contact and photocatalysis. In this study, a new method based on ball milling technology was developed to efficiently produce GDY and hydrogen substituted graphdiyne (H-GDY), and it was proved that H-GDY can achieve efficient interface contact and promote the separation of interface charges to improve photocatalytic hydrogen evolution. The experimental and theoretical calculation results show that the high work function of H-GDY can enlarge the larger work function difference (ΔΦ) between NiSe2, which drives the effective transfer of charges at the interface, and then forms a stronger built-in electric field, thus significantly improving the separation efficiency of photogenerated electrons and holes.

Asymmetrical anchor way of manganese atoms on carbon domain edge for enhanced oxygen reduction reaction

Single atomic catalysts (SACs), especially the catalysts featured by well-developed M-N4 moieties, show excellent catalytic activity and spark enormous attention. However, the highly symmetric active sites may result in some degenerate electronic states for the d orbitals of the center metal atom, which suffer from the unsatisfactory adsorption-desorption behaviors during reaction. Herein, we develop an asymmetric anchor site by two types of nitrogen (sp-N and pyridinic N) created in the inherent edge-rich carbon domain of hydrogen-substituted graphdiyne (HsGDY), where atomic catalyst like manganese atoms can be asymmetrically anchored on the one side of hexagon carbon rings. The abundant elegant hexagon carbon rings on HsGDY not only facilitate the creation of edge sites, but also provide available space for the coordination of terminal ligands (OH) with Mn atoms. The as-synthesized Mn-N-HsGDY exhibits excellent ORR activity and an impressive long-term cyclability for over 3800 cycles in a rechargeable Zn-air battery.

HsGDY 3D Framework-Encapsulated Cu2O Quantum Dots for High-Efficiency Energy Storage.

Nanostructured electrode materials become a vital component for future electrode materials because of their short electron and ion transport distances for fast charge and discharge processes and sufficient space between particles for volume expansion. So, achieving a smaller size of the nanomaterial with stable structure and high electrode performance is always the pursuit. Herein, the hybrid electrode material system hydrogen-substituted graphdiyne (HsGDY)/Cu2O-quantum dots (QDs) composed of an active carbon substrate and vibrant metal oxide QD load was established by HsGDY and cuprous oxide. The HsGDY frame with conjugated structure not only delivers impressive capacity by a self-exchange mechanism but also characterizes a matrix to forge strong connections with numerous active Cu2O-QDs for the prevention of aggregation, leading to a homogeneous storage and transport of charge in a bulk material of crisscross structural pores. QD-based electrode materials would exhibit desired capacities by their large surface area, abundant active surface atoms, and the short diffusion pathway. The hybrid system of HsGDY/Cu2O-QDs delivers an ultrahigh capacity of 1230 mA h g-1 with loading density reaching up to 1 mg cm-2. In the meantime, the electrode exhibits a long cycle stability of over 8000 cycles. The synergistic effect endows the hybrid system electrode with an approximately theoretical energy density, suggesting the great potential of such carbon/QD hybrid material system applied for high-performance batteries.

Unveiling the Computational Insights into Na‐Decorated Hydrogen‐Substituted Graphdiyne for Efficient Tracing and Trapping of Nitrogen and its Oxides

Addressing air pollution is a critical concern, particularly in the context of tracing and trapping nitrogen and its oxides (N2, N2O, NO, NO2) emitted from fuel combustion. In this context, this study delves into the potential of recently discovered Hydrogen-substituted Graphdiyne (HsGDY) and to enhance its adsorption capabilities by incorporating sodium (Na) metal atom computationally. Herein, the strategic sites for Na atom decoration on HsGDY is identified and the most stable site R1 with Eads = −0.820 eV is chosen for subsequent NOx adsorption studies. Through DFT calculations, we assess the adsorptive capacity of NOx gases onto both HsGDY and Na-decorated HsGDY (NaHsGDY) slabs. In particular NO2 gas molecule with Eads = −2.537 eV emphasizes greater adsorption over NaHsGDY slab. Analysis of electronic properties reveals significant reduction in the energy gap (Eg) of the NaHsGDY, indicating heightened reactivity toward NOx gases thereby resulting in substantial increase in the slab’s conductivity. Additionally, charge density difference and Löwdin charge analyses provides consistent evidence supporting enhancement in charge transfer during NOx gases adsorption after Na decoration. The NaHsGDY slab demonstrates high selectivity, sensitivity, and superior performance than HsGDY slab, positioning it as a promising candidate for targeted NOx gas molecules detection.

Lithiophilic Hydrogen-Substituted Graphdiyne Aerogels with Ionically Conductive Channels for High-Performance Lithium Metal Batteries.

Lithium (Li) metal stands as a promising anode in advancing high-energy-density batteries. However, intrinsic issues associated with metallic Li, especially the dendritic growth, have hindered its practical application. Herein, we focus on molecular combined structural design to develop dendrite-free anodes. Specifically, using hydrogen-substituted graphdiyne (HGDY) aerogel hosts, we successfully fabricated a promising Li composite anode (Li@HGDY). The HGDY aerogel's lithiophilic nature and hierarchical pores drive molten Li infusion and reduce local current density within the three-dimensional HGDY host. The unique molecular structure of HGDY provides favorable bulk pathways for lithium-ion transport. By simultaneous regulation of electron and ion transport within the HGDY host, uniform lithium stripping/platting is fulfilled. Li@HGDY symmetric cells exhibit a low overpotential and stable cycling. The Li@HGDY||lithium iron phosphate full cell retained 98.1% capacity after 170 cycles at 0.4 C. This study sheds new light on designing high-capacity and long-lasting lithium metal anodes.

The thermal instability of hydrogen-substituted graphdiyne and its role in lithium-sulfur batteries.

This study reveals the role of thermal instability in hydrogen-substituted graphdiyne (HsGDY) and its impact on lithium-sulfur (Li-S) battery performance. HsGDY undergoes significant chemical and physical transformations when subjected to thermal heating, both in the presence and absence of sulfur. Our findings suggest that the structural transformation of HsGDY into a graphene-like structure is primarily responsible for enhancing sulfur trapping and reducing the polysulfide shuttle effect, rather than the previously hypothesized alkyne-sulfur chemical interactions.

Graphdiyne-based integrated membrane for enhanced alcohol-permselective pervaporation

Exploring nano-engineered polymeric membrane with a customized architecture is urgent for the advance of alcoholophilic pervaporation. Graphdiyne (GDY) is a promising candidate material for constructing alcohol-permselective membranes due to its unique alkyne-rich framework in terms of well-organized porous system and strong hydrophobicity. Herein, we report a GDY-based integrated membrane composed of a loosened hydrogen-substituted GDY (HsGDY)-polydimethylsiloxane (PDMS) mixed-matrix layer on a polysulfone ultrafiltration support and a moderate pore-filling PDMS crosslinking layer. The procedure for fabricating such an integrated bilayer membrane was implemented by a simple vacuum-assisted filtration followed a dip-coating post-treatment. The resultant HsGDY-based integrated membrane shows a separation factor of 12.8 together with a total flux of 1535.7 g m−2 h−1 in the separation of a 5.0 wt% ethanol-water solution. The overall performance is also competitive among the reported ethanol-permeselective membranes, benefiting from the synergy of alcohol adsorption-preferential permeation processes by the HsGDY-based integrated bilayers. A continuous and long-term pervaporation test indicates the robust operating stability. An enhanced separation performance for other alcohols (C1–C4) suggests the great potential of HsGDY-based integrated membranes for in situ recovery of bioalcohols.

In situ Construction of Multistage Core-Shell Nanostructure as Bifunctional Catalyst for Ultrastable Zinc-Air Batteries.

Many efforts have been devoted to obtaining excellent cathode catalysts for Zinc air batteries (ZABs), but the inevitable use of binder will damage the catalytic activity and weaken long-term stability, inefficient mass transfer of oxygen is also chargable for the limited activity. Herein, in situ grown hydrogen substituted graphdiyne (HGDY) on carbon paper has been prepared and used as cathode catalyst layer in ZABs. Multiple catalytic sites are firmly combined and end with the boosted bifunctional catalytic activity of oxygen reduction and oxygen evolution. Moreover, the specific surface area, sufficient active sites, multilevel pore nanostructure and robust conductivity are fully exposed to establish efficient catalytic interface and skeleton. Cu/Co nanoparticles are uniformly distributed and warped by HGDY network, which can stably exist during the catalytic process. As a result, a current density of 18.75mAcm-2 and a Tafel slope of 61.06mVdec-1 for oxygen reduction and a ultralong operation for more than 2300h in aqueous ZAB have been achieved, which is beyond many reported bifunctional catalysts in ZAB system.

Introducing hydroxyl groups to tailor the d-band center of Ir atom through side anchoring for boosted ORR and HER

Tuning the coordination atoms of central metal is an effective means to improve the electrocatalytic activity of atomic catalysts. Herein, iridium (Ir) is proposed to be asymmetrically anchored by sp-N and pyridinic N of hydrogen-substituted graphdiyne (HsGDY), and coordinated with OH as an Ir atomic catalyst (Ir1-N-HsGDY). The electron structures, especially the d-band center of Ir atom, are optimized by these specific coordination atoms. Thus, the as-synthesized Ir1-N-HsGDY exhibits excellent electrocatalytic performances for oxygen reduction and hydrogen evolution reactions in both acidic and alkaline media. Benefiting from the unique structure of HsGDY, IrN2(OH)3 has been developed and demonstrated to act as the active site in these electrochemical reactions. All those indicate the fresh role of the sp-N in graphdiyne in producing a new anchor way and contributing to promote the electrocatalytic activity, showing a new strategy to design novel electrochemical catalysts.

Fabrication of multiple core-shell structures MnO@HsGDY@NC@HsGDY hybrid nanofibers for enhanced microwave absorption

Optimizing the structure and composition of emerging materials to produce efficient absorbers are one strategy for addressing electromagnetic pollution and radar stealth. For the first time, hydrogen-substituted graphdiyne (HsGDY) is used as a functional component for the preparation of microwave-absorbing materials in this paper. By using MnO2 nanowires as template and sequentially coating HsGDY, polydopamine (PDA) and HsGDY shell layers, MnO2@HsGDY@PDA@HsGDY nanowire precursors are obtained. The one-dimensional (1D) nanowires combine the advantages of multicomponent composite, multiple core-shell structures. After calcination, 1D microwave absorption absorber MnO@HsGDY@NC@HsGDY with multi-layer and core-shell structures is produced. The high conductivity of HsGDY enhances the material's dielectric loss, and the multiple heterogeneous interfaces in the material structure cause interface polarization, resulting in the excellent microwave absorption properties. MnO@HsGDY@NC@HsGDY exhibits the advantages of low filler content, thin matching thickness, strong microwave absorption capacity and wide effective absorption band (EAB). The minimum reflection loss (RLmin) can reach −68.57 dB@13.8 GHz@2.4 mm, and the EAB is 6.7 GHz as the filler content is 11 %. This work enriches the types of 1D materials and absorbers, expands the application fields of HsGDY, and provides a reference for the design and preparation of absorbers.

The synthesis of MNC5 active site for electrochemical catalysis

Metal-nitrogen-carbon (M-N-C) catalysts with M-Nx (x = 2 or 4) sites on graphene substrate are researched intensively nowadays. However, the simple and repetitive hexatomic ring structure of graphene limits the exploration of novel efficient active sites for catalysis. Herein, a new carbon material, hydrogen-substituted graphdiyne (HsGDY), is designed as the substrate to develop new active sites. Benefiting from the unique sp and sp2 hybridized carbon atoms of HsGDY, aromatic rings in HsGDY can fix Fe single atoms, creating novel FeC6 and FeNC5 active sites. The as-synthesized Fe-N-HsGDY catalyst displays much higher activity than commercial Pt/C and is found to be one of the highest activities among the reported non-noble metal catalysts for oxygen reduction reaction (ORR). FeNC5 site with graphitic-N has been verified experimentally and theoretically as an efficient active site for ORR. Those results indicate that the rational choice of specific substrate materials with novel structures will broaden the path of creating new active sites with efficient activity.

Pseudospin Polarized Dual-Higher-Order Topology in Hydrogen-Substituted Graphdiyne.

Although the topological band theory is applicable to both Fermionic and bosonic systems, the same electronic and phononic topological phases are seldom reported in one natural material. In this work, we show the presence of a dual-higher-order topology in hydrogen-substituted graphdiyne (H-GDY) by first-principles calculations. The intriguing enantiomorphic flat-bands are realized in both electronic and phononic bands of H-GDY, which is confirmed to be an organic 2D second-order topological insulator (SOTI). Most importantly, we found that the topological corner states are pseudospin polarized in H-GDY, exhibiting a clockwise or counterclockwise texture perpendicular to the radial direction. Our results not only identify the existence of the dual-higher-order topology in covalent organic frameworks but also uncover a unique pseudospin polarization-coordinate locking relation, further extending the well-known spin-momentum locking relation in conventional topological insulators.

Ni Anchored to Hydrogen-Substituted Graphdiyne for Lithium Sulfide Cathodes in Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are promising candidates for next-generation energy storage systems due to their high theoretical energy density and the low cost of sulfur. However, slow conversion kinetics between the insulating S and lithium sulfide (Li2S) remains as a technical challenge. In this work, we report a catalyst featuring nickel (Ni) single atoms and clusters anchored to a porous hydrogen-substituted graphdiyne support (termed Ni@HGDY), which is incorporated in Li2S cathodes. The rapidly synthesized catalyst was found to enhance ionic and electronic conductivity, decrease the reaction overpotential, and promote more complete conversion between Li2S and sulfur. The addition of Ni@HGDY to commercial Li2S powder enabled a capacity of over 516 mAh gLi2S-1 at 1 C for over 125 cycles, whereas the control Li2S cathode managed to maintain just over 200 mAh gLi2S-1. These findings highlight the efficacy of Ni as a metal catalyst and demonstrate the promise of HGDY in energy storage devices.

Hierarchical 3D Porous Hydrogen-Substituted Graphdiyne for High-Performance Electrochemical Lithium-Ion Storage.

Graphdiyne (GDY) has realized significant achievements in lithium-ion batteries (LIBs) because of its unique π-conjugated skeleton with sp- and sp2-hybridized carbon atoms. Enriching the accessible surface areas and diffusion pathways of Li ions can realize more storage sites and rapid transport dynamics. Herein, three-dimensional porous hydrogen-substituted GDY (HsGDY) is developed for high-performance Li-ion storage. HsGDY, fabricated via a versatile interface-assisted synthesis strategy, exhibits a large specific surface area (667.9 m2 g-1), a hierarchical porous structure, and an expanded interlayer space, which accelerate Li-ion accessibility and lithiation/delithiation. Owing to this high π-conjugated, conductive, and porous framework, HsGDY exhibits a large reversible capacity (930 mA h g-1 after 100 cycles at 1 A g-1), superior cycle (720 mA h g-1 after 300 cycles at 1 A g-1), and rate (490 mA h g-1 at 5 A g-1) performances. Density functional theory calculations of the low diffusion barrier in the lamination and vertical directions further reveal the fast Li-ion transport kinetics of HsGDY. Additionally, a LiCoO2-HsGDY full cell is constructed, which exhibits a good practical charge/discharge capacity of 128 mA h g-1 and stable cycling behavior. This study highlights the advanced design of next-generation LIBs to sustainably develop the new energy industry.