Graphdiyne: An Efficient Hole Transporter for Stable High‐Performance Colloidal Quantum Dot Solar Cells

Graphdiyne, a novel large π‐conjugated carbon hole transporting material, is employed as anode buffer layer in colloidal quantum dots solar cells. Power conversion efficiency is notably enhanced to 10.64% from 9.49% compared to relevant reference devices. Hole transfer from the quantum dot solid active layer to the anode can be appreciably enhanced only by using graphdiyne to lower the work function of the colloidal quantum dot solid. It is found that the all‐carbon buffer layer prolongs the carrier lifetime, reducing surface recombination on the previously neglected back side of the photovoltaic device. Remarkably, the device also shows high long‐term stability in ambient air. The results demonstrate that graphdiyne may have diverse applications in enhancing optoelectronic devices.     

Efficient Hydrogen Production on a 3D Flexible Heterojunction Material

A novel heterojunction material, with electron‐rich graphdiyne as the host and molybdenum disulfide as the catalytic center (eGDY/MDS), to produce ultraefficient hydrogen‐evolution reaction (HER) at all pH values is described. It is a surprise that the metallic conductor combined from two semiconductor materials, eGDY and MDS, leads to optimal free energy (ΔG_H) and enhancement in the intrinsic HER catalytic performances. The calculated and experimental results indicate that eGDY/MDS shows greatly enhanced catalytic activities and high stabilities in both acidic and alkaline conditions; these approach the outstanding performances of the state‐of‐the‐art noble‐metal‐based catalysts. The eGDY/MDS shows better activity than Pt/C in alkaline media and remarkable enhancement in photocurrent density. The high catalytic activity of eGDY/MDS originates from facilitated electronic transfer kinetics, high conductivity, more exposed catalytic active sites, and excellent mass transport.     

Graphdiyne and its Assembly Architectures: Synthesis,Functionalization, and Applications

Graphdiyne (GDY), a novel one‐atom‐thick carbon allotrope that features assembled layers of sp‐ and sp²‐hybridized carbon atoms, has attracted great interest from both science and industry due to its unique and fascinating structural, physical, and chemical properties. GDY‐based materials with different morphologies, such as nanowires, nanotube arrays, nanosheets, and ordered stripe arrays, have been applied in various areas such as catalysis, solar cells, energy storage, and optoelectronic devices. After an introduction to the fundamental properties of GDY, recent advances in the fabrication of GDY‐based nanostructures and their applications, and corresponding mechanisms, are covered, and future critical perspectives are also discussed.     

Graphdiyne‐Based Materials: Preparation and Application for Electrochemical Energy Storage

Graphdiyne (GDY) has drawn much attention for its 2D chemical structure, extraordinary intrinsic properties, and wide application potential in a variety of research fields. In particular, some structural features and basic physical properties including expanded in‐plane pores, regular nanostructuring, and good transporting properties make GDY a promising candidate for an electrode material in energy‐storage devices, including batteries and supercapacitors. The chemical structure, synthetic strategy, basic chemical–physical properties of GDY, and related theoretical analysis on its energy‐storage mechanism are summarized here. Moreover, through a view of the mutual promotion between the structure modification of GDY and the corresponding electrochemical performance improvement, research progress on the application of GDY for electrochemical energy storage is systematically explored and discussed. Furthermore, the development trends of GDY in energy‐storage devices are also comprehensively assessed. GDY‐based materials represent a bright future in the field of electrochemical energy storage.     

Graphdiyne-Based Flexible Photodetectors with High Responsivity and Detectivity

Graphdiyne (GDY), a newly emerging 2D carbon allotrope, has been widely explored in various fields owing to its outstanding electronic properties such as the intrinsic bandgap and high carrier mobility. Herein, GDY-based photoelectrochemical-type photodetection is realized by spin-coating ultrathin GDY nanosheets onto flexible poly(ethylene terephthalate) (PET) substrates. The GDY-based photodetectors (PDs) demonstrate excellent photo-responsive behaviors with high photocurrent (P_ph, 5.98 µA cm ^{- 2}), photoresponsivity (R_ph, 1086.96 µA W ^{- 1}), detectivity (7.31 × 10¹⁰ Jones), and excellent long-term stability (more than 1 month). More importantly, the PDs maintain an excellent P_ph after 1000 cycles of bending (4.45 µA cm ^{- 2}) and twisting (3.85 µA cm ^{- 2}), thanks to the great flexibility of the GDY structure that is compatible with the flexible PET substrate. Density functional theory (DFT) calculations are adopted to explore the electronic characteristics of GDY, which provides evidence for the performance enhancement of GDY in alkaline electrolyte. In this way, the GDY-based flexible PDs can enrich the fundamental study of GDY and pave the way for the exploration of GDY heterojunction-based photodetection.     

Ultrathin Graphdiyne Nanowires with Diameters below 3 nm: Synthesis,Photoelectric Effect,and Enhanced Raman Sensing

Due to the intrinsic layered structure, graphdiyne (GDY) strongly tends to form 2D materials, therefore, most of the current research are based on GDY 2D structures. Up to now, the synthesis of its ultrathin nanowires with a high aspect ratio has not been reported. Here, the ultrathin GDY nanowires with diameters below 3 nm are reported for the first time by a two-phase interface synthesis method, which has excellent crystallinity and an aspect ratio of more than 2500. Evidence shows that the GDY ultrathin nanowires are formed by the oriented-attachment mechanism of nanoparticles. The GDY ultrathin nanowires exhibit a significant quantum confinement effect, enhanced photoelectric effect, and promising applications in surface-enhanced Raman sensing.     

Low-Density Multilayer Graphdiyne Film with Excellent Energy Dissipation Capability under Micro-Ballistic Impact

Dynamical performance of multilayer graphdiyne (MLGDY) with ultra-low density and flexible features is investigated using laser-induced micro-projectile impact testing (LIPIT) and molecular dynamics (MD) simulations. The results reveal that the MLGDY exhibits excellent dynamic energy dissipation ability mainly due to the excellent in-plane wave velocity resulting from the diacetylene linkages between benzene rings. In addition, the unique multiple crack tips and their propagation further promote the energy dissipation capability. The energy dissipation capability of the MLGDY is found to reduce with increasing thickness due to compression-shear induced failure of several upper layers of relatively thick MLGDY, which hinders delocalized energy dissipation ability. Moreover, the impact resistance force of the MLGDY increases almost linearly with increasing impact velocity, demonstrating the applicability of the traditional compressive resistance theory of laminates for MLGDY. Based on the experimental observation and the simulation results, two feasible strategies, i.e., combining with high-strength multi-layer graphene and rotated graphdiyne (GDY) interlayer to avoid stacking of sp-hybridized carbon atoms, are proposed to further improve the impact resistance of the MLGDY. The study provides direct proof of excellent impact resistance of the versatile MLGDY and proposes feasible fabrication strategies to further improve the anti-ballistic performance in future.     

Design of Graphdiyne and Holey Graphyne-Based Single Atom Catalysts for CO2 Reduction With Interpretable Machine Learning

Using electrochemical CO₂ reduction reaction (CO₂RR) to synthesize value-added hydrocarbons provides a useful solution for environmental issues and energy crisis. However, this process is impeded by the low activity and selectivity of electrocatalysts toward targeted products. Employing density functional theory computations, the graphdiyne and holey graphyne supported single-atom catalysts (SACs, M/GDY and M/HGY) are demonstrated to be the promising candidates for the CO₂RR. By taking full elemental diversity of metal sites across the periodic table, 25 catalysts are found to effectively activate CO₂ and inhibit competitive hydrogen evolution, and 8 of them show higher activity for CH₄ production than Cu(211). Remarkably, changing supports are found to greatly affect limiting potentials and reaction pathways, even leading to an “inert-active” transition for some metal centers. The resulting SACs, including Mn/GDY, Co/HGY, Ru/GDY, and Os/GDY, can achieve high activity with low limiting potentials of ≈ −0.22 to −0.58 V. Machine learning enables to identify the critical role of the polarized charge and magnetic moment of metal atoms in affecting the activity. The built machine learning model also shows an interpretable capability to predict the activity of the other types of SACs, offering a great promise to quick screening of high-performance SACs.     

Adaptive Interfacial Contact between Copper Nanoparticles and Triazine Functionalized Graphdiyne Substrate for Improved Lithium/Sodium Storage

The high activity of nano-sized metal particles (NMPs) makes it easy to appear uncontrolled aggregation, which seriously affects Li/Na storage in electrode materials. Introducing adaptive substrates with proper affinity to NMPs is an effective strategy that optimizes the stability and capacity of the related electrodes. Herein, a comprehensive strategy for the fabrication of adaptive interfacial contacts between metallic Cu nanoparticles (NPs) and triphenyl-substituted triazine graphdiyne (TPTG) substrates is reported. The sp C in the acetylenic linkers and N heteroatoms in the triazine groups synergistically stabilized the Cu NPs loaded onto the TPTG substrates. The stabilizing effect of the TPTG substrate induces a reversible lattice change of the Cu NPs during the charge–discharge process, thus efficiently facilitating the stable transfer of Li⁺/Na⁺. Intrinsic mechanism analysis indicates that the heterojunction contact interface of Cu NPs/TPTG provides branched charge transfer pathways from Li/Na to the Cu NPs and TPTG substrates, which synergistically adjusts the affinity to Li/Na atoms and ultimately improves the electrochemical performance in Li/Na storage. The investigation of the structure–property relationship deepens the understanding of the function of heterointerfaces, which is essential for optimizing the performance of energy storage devices.