Spontaneously Splitting Copper Nanowires into Quantum Dots on Graphdiyne for Suppressing Lithium Dendrites

As an emerging carbon allotrope, the controllable growth of graphdiyne has been an important means to explore its unique scientific properties and applications. In this work, the effect of the crystal structure of copper (Cu) on the growth of graphdiyne is systematically studied. It is found that the crystal boundaries are the origin of the reaction activity. The polycrystalline Cu nanowire with many crystal boundaries is spontaneously split into Cu quantum dots (about 3 nm) by the grown graphdiyne. These Cu quantum dots are uniformly dispersed on the graphdiyne, and they block the long-range ordered growth of the graphdiyne. These Cu quantum dots in situ supported on graphdiyne demonstrate high efficiency in inhibiting the growth of lithium dendrites in lithium metal batteries. Based on this interesting finding, the Cu quantum dots anchored on the all-carbon graphdiyne can be prepared on a large scale, and unique applications of Cu quantum dots in electrochemical fields can be implemented.     

Progress and Prospects of Graphdiyne‐Based Materials in Biomedical Applications

Graphdiyne is a new member of the family of carbon‐based nanomaterials that possess two types of carbon atoms, sp‐ and sp²‐hybridized carbon atoms. As a novel 2D carbon‐based nanomaterial with unique planar structure, such as uniformly distributed nanopores and large conjugated structure, graphdiyne has shown many fascinating properties in mechanics, electronics, and optics since it was first experimentally synthesized in 2010. Up to now, graphdiyne and its derivatives have been reported to be successfully applied in many areas, such as catalysis, energy, environment, and biomedicine, due to these excellent properties. Herein, the current research progress of graphdiyne‐based materials in biomedical fields is summarized, including biosensing, biological protection, cancer therapy, tissue engineering, etc. The advantages of graphdiyne and its derivatives are presented and compared with other carbon‐based materials. Considering the potential biomedical and clinical applications of graphdiyne‐based materials, the toxicity and biocompatibility are also discussed based on current studies. Finally, future perspectives and possible biomedical applications of graphdiyne‐based materials are also discussed.     

Exploring Approaches for the Synthesis of Few‐Layered Graphdiyne

Graphdiyne (GDY) is an emerging carbon allotrope in the graphyne (GY) family, demonstrating extensive potential applications in the fields of electronic devices, catalysis, electrochemical energy storage, and nonlinear optics. Synthesis of few‐layered GDY is especially important for both electronic applications and structural characterization. This work critically summarizes the state‐of‐art of GDY and focuses on exploring approaches for few‐layered GDY synthesis. The obstacles and challenges of GDY synthesis are also analyzed in detail. Recently developed synthetic methods are discussed such as i) the copper substrate‐based method, ii) the chemical vapor deposition (CVD) method, iii) the interfacial construction method, and iv) the graphene‐templated method. Throughout the discussion, the superiorities and limitations of different methods are analyzed comprehensively. These synthetic methods have provided considerable inspiration approaching synthesis of few‐layered or single‐layered GDY film. The work concludes with a perspective on promising research directions and remaining barriers for layer‐controlled and morphology‐controlled synthesis of GDY with higher crystalline quality.     

Functionalized Graphdiyne Nanowires: On‐Surface Synthesis and Assessment of Band Structure,Flexibility, and Information Storage Potential

Carbon nanomaterials exhibit extraordinary mechanical and electronic properties desirable for future technologies. Beyond the popular sp²‐scaffolds, there is growing interest in their graphdiyne‐related counterparts incorporating both sp² and sp bonding in a regular scheme. Herein, we introduce carbonitrile‐functionalized graphdiyne nanowires, as a novel conjugated, one‐dimensional (1D) carbon nanomaterial systematically combining the virtues of covalent coupling and supramolecular concepts that are fabricated by on‐surface synthesis. Specifically, a terphenylene backbone is extended with reactive terminal alkyne and polar carbonitrile (CN) moieties providing the required functionalities. It is demonstrated that the CN functionalization enables highly selective alkyne homocoupling forming polymer strands and gives rise to mutual lateral attraction entailing room‐temperature stable double‐stranded assemblies. By exploiting the templating effect of the vicinal Ag(455) surface, 40 nm long semiconducting nanowires are obtained and the first experimental assessment of their electronic band structure is achieved by angle‐resolved photoemission spectroscopy indicating an effective mass below 0.1m₀ for the top of the highest occupied band. Via molecular manipulation it is showcased that the novel oligomer exhibits extreme mechanical flexibility and opens unexplored ways of information encoding in clearly distinguishable CN‐phenyl trans–cis species. Thus, conformational data storage with density of 0.36 bit nm^?2 and temperature stability beyond 150 K comes in reach.     

Hydrogen-Substituted Graphdiyne Ion Tunnels Directing Concentration Redistribution for Commercial-Grade Dendrite-Free Zinc Anodes

Current aqueous Zn batteries (ZBs) seriously suffer from dendrite issues caused by rough electrode surfaces. Despite significant efforts in prolonging lifespan of these batteries, little effort has been devoted to dendrite elimination in commercial-grade cathode loading mass. Instead, demonstrations have only been done at the laboratory level (≤2 mg cm⁻²). Additionally, new dilemmas regarding change of the proton-storage behavior and interface pulverization have emerged in turn. Herein, hydrogen-substituted graphdiyne (HsGDY), with sub-ångström level ion tunnels and robust chemical stability, is designed as an artificial interface layer to address these issues. This strategy prolongs the symmetric cell lifespan to >2400 h (100 days), which is 37 times larger than without protection (63 h). The simulation of dual fields reveals that HsGDY can redistribute the Zn²⁺ concentration field by spatially forcing Zn²⁺ to deviate from the irregular electric field. During practical use, the as-assembled full batteries deliver a long lifespan 50 000 cycles and remain stable even at a commercial-grade cathode loading mass of up to 22.95 mg cm⁻². This HsGDY-protection methodology represents great progress in Zn dendrite protection and demonstrates enormous potential in metal batteries.     

Fabrication of Graphdiyne/Graphene Composite Microsphere with Wrinkled Surface via Ultrasonic Spray Compounding and its Microwave Absorption Properties

Advanced carbon materials are constantly being used in the field of microwave absorption. Herein, in order to enrich the variety and expand the application fields of graphdiyne (GDY), the wrinkled graphene (RGO) nanosheet coated and embedded with GDY porous microspheres (RGO/GDY) are prepared by GDY synthesis, ultrasonic spray, and pyrolysis. The study finds that RGO and GDY have effective synergistic effects. The suitable pores and composition, conductive network formed by overlapping 0D and 2D materials, special surface and internal morphology design, and high-temperature activation process make RGO/GDY exhibit excellent impedance matching and attenuation capabilities. Under the best amount of GDY (20 mg), the particle sizes of the microspheres (≈6 µm), and filler content (27.5%), the minimum reflection loss (RL_min) is −58 dB@8.3 GHz, and the corresponding matching thickness is 2.7 mm. The effective absorption bandwidth is 4.3 GHz as the thickness is 1.9 mm. By adjusting the thickness, the absorber can completely absorb microwaves of all the C, X, and Ku bands. The microwave absorbing mechanisms are elucidated. GDY materials are first applied to the field of microwave absorption, enhancing the absorption performance of RGO/GDY. It provides a new way to manufacture electromagnetic wave absorbers with satisfactory performance.     

Architecture of β‐Graphdiyne‐Containing Thin Film Using Modified Glaser–Hay Coupling Reaction for Enhanced Photocatalytic Property of TiO2

β‐Graphdiyne (β‐GDY) is a member of 2D graphyne family with zero band gap, and is a promising material with potential applications in energy storage, organic electronics, etc. However, the synthesis of β‐GDY has not been realized yet, and the measurement of its intrinsic properties remains elusive. In this work, β‐GDY‐containing thin film is successfully synthesized on copper foil using modified Glaser–Hay coupling reaction with tetraethynylethene as precursor. The as‐grown carbon film has a smooth surface and is continuous and uniform. Electrical measurements reveal the conductivity of 3.47 × 10^?6 S m^?1 and the work function of 5.22 eV. TiO₂@β‐GDY nanocomposite is then prepared and presented with an enhancement of photocatalytic ability compared to pure TiO₂.     

Grain Boundary Perfection Enabled by Pyridinic Nitrogen Doped Graphdiyne in Hybrid Perovskite

The solution processing in hybrid perovskite films inevitably results in the formation of detrimental defects at grain boundaries (GBs) that deteriorate the optoelectronic properties and bring about severe hysteresis as well as operational instability. Here, an effective scenario to alleviate the imperfection issue at perovskite GBs via incorporating pyridinic nitrogen-doped graphdiyne (N-GDY) is proposed. Taking full advantage of periodic acetylenic linkages and introduced pyridinic N atoms, the deep-level trap states like Pb–I antisite defects and under-coordinated Pb atoms are considerably passivated, thus diminishing the undesired non-radiative recombination. Additionally, the spatial confinement coupling with electrostatic repulsion effect originated from the intrinsic 2D structure of N-GDY, has been identified to deal with the halide ion migration behavior. Such contributions are further theoretically evidenced with the charge density delocalization as well as the ion migration energy barrier elevation. The authors unprecedentedly verified the superiorities based on the flexible chemical-tailorability of atomic crystal GDY materials toward polycrystalline perovskite related energy conversion devices.     

Metal‐Tuned Acetylene Linkages in Hydrogen Substituted Graphdiyne Boosting the Electrochemical Oxygen Reduction

Different from graphene with the highly stable sp²‐hybridized carbon atoms, which shows poor controllability for constructing strong interactions between graphene and guest metal, graphdiyne has a great potential to be engineered because its high‐reactive acetylene linkages can effectively chelate metal atoms. Herein, a hydrogen‐substituted graphdiyne (HsGDY) supported metal catalyst system through in situ growth of Cu₃Pd nanoalloys on HsGDY surface is developed. Benefiting from the strong metal‐chelating ability of acetylenic linkages, Cu₃Pd nanoalloys are intimately anchored on HsGDY surface that accordingly creates a strong interaction. The optimal HsGDY‐supported Cu₃Pd catalyst (HsGDY/Cu₃Pd‐750) exhibits outstanding electrocatalytic activity for the oxygen reduction reaction (ORR) with an admirable half‐wave potential (0.870 V), an impressive kinetic current density at 0.75 V (57.7 mA cm^?2) and long‐term stability, far outperforming those of the state‐of‐the‐art Pt/C catalyst (0.859 V and 15.8 mA cm^?2). This excellent performance is further highlighted by the Zn–air battery using HsGDY/Cu₃Pd‐750 as cathode. Density function theory calculations show that such electrocatalytic performance is attributed to the strong interaction between Cu₃Pd and C?C bonds of HsGDY, which causes the asymmetric electron distribution on two carbon atoms of C?C bond and the strong charge transfer to weaken the shoulder‐to‐shoulder π conjugation, eventually facilitating the ORR process.