Hydrogen-substituted Graphdiyne Research Articles

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.

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.

Hemocompatible Functionalized Hydrogen Substituted Graphdiyne Based Highly Durable Biosensor for Liver Cancer Detection.

Present work focuses on the development of a highly durable biosensor for liver cancer (LC) biomarker (Annexin A2; ANXA2) detection. In this work, we have modified hydrogen substituted graphdiyne (HsGDY) using an organofunctional silane [3-(aminopropyl)triethoxysilane (APTES)], leveraging the opposite surface polarities on HsGDY and APTES to fabricate a highly hemocompatible functionalized nanomaterial matrix. The high hemocompatibility of APTES functionalized HsGDY (APTES/HsGDY) allows long-term stabilized immobilization of antibodies in their native state, hence increasing the durability of the biosensor. The biosensor was fabricated using electrophoretic deposition (EPD) of APTES/HsGDY onto an indium tin oxide (ITO)-coated glass substrate at 40% lower DC potential than nonfunctionalized HsGDY with successive immobilization of monoclonal antibodies of ANXA2 (anti-ANXA2) and bovine serum albumin (BSA). The synthesized nanomaterials and fabricated electrodes were investigated using a zetasizer and spectroscopic, microscopic, and electrochemical (cyclic voltammetry and differential pulse voltammetry) techniques. The developed immunosensor (BSA/anti-ANXA2/APTES/HsGDY/ITO) could detect ANXA2 in a linear detection range from 100 fg mL-1 to 100 ng mL-1 with a lower detection limit of 100 fg mL-1. The biosensor demonstrated excellent storage stability of 63 days along with high accuracy toward detection of ANXA2 in serum samples of LC patients as validated via enzyme-linked immunosorbent assay technique.

Ultra-high-efficiency capture of lead ions over acetylenic bond-rich graphdiyne adsorbent in aqueous solution

A satisfactory material with high adsorption capacity is urgently needed to solve the serious problem of environment and human health caused by lead pollution. Herein, hydrogen-substituted graphdiyne (HsGDY) was successfully fabricated and employed to remove lead ions from sewage and lead-containing blood. The as-prepared HsGDY exhibits the highest adsorption capacity of lead among the reported materials with a maximum adsorption capacity of 2,390 mg/g, i.e., ~five times larger than that of graphdiyne (GDY). The distinguished hexagonal hole and stack mode of HsGDY allows the adsorption of more lead via its inner side adsorption mode in one single unit space. In addition, the Pb 6s and H 1s hybridization promotes the strong bonding of lead atom adsorbed at the acetylenic bond of HsGDY, contributing to the high adsorption capacity. HsGDY can be easily regenerated by acid treatment and showed excellent regeneration ability and reliability after six adsorption-regeneration cycles. Langmuir isotherm model, pseudo second order, and density functional theory (DFT) demonstrated that the lead adsorption process in HsGDY is monolayer chemisorption. Furthermore, the HsGDY-based portable filter can handle 1,000 μg/L lead-containing aqueous solution up to 1,000 mL, which is nearly 6.67 times that of commercial activated carbon particles. And, the HsGDY shows good biocompatibility and excellent removal efficiency to 100μg/L blood lead, which is 1.7 times higher than that of GDY. These findings suggest that HsGDY could be a promising adsorbent for practical lead and other heavy metal removal.

Ultra-Fast Preparation of Large-Area Graphdiyne-Based Membranes via Alkynylated Surface-Modification for Nanofiltration.

Graphdiynes (GDYs), two-dimensional graphene-like carbon systems, are considered as potential advanced membrane material due to their unique physicochemical features. Nevertheless, the scale-up of integrated GDY membranes is technologically challenging, and most studies remain at the theoretical stage. Herein, we report a simple and efficient alkynylated surface-mediated strategy to prepare hydrogen-substituted graphdiyne (HsGDY) membranes on commercial alumina tubes. Surface alkynylation initiates an accelerated surface-confined coupling reaction in the presence of a copper catalyst and facilitates the nanoscale epitaxial lateral growth of HsGDY. A continuous and ultra-thin HsGDY membrane (∼100 nm) can be produced within 15 min. The resulting membranes exhibit outstanding molecular sieving together with excellent water permeances (ca. 1100 L m-2 h-1 MPa-1 ), and show a long-term durability in cross-flow nanofiltration, owing to the superhydrophilic surface and hydrophobic pore walls.

Interfacial Engineering of Bimetallic Ni/Co-MOFs with H-Substituted Graphdiyne for Ammonia Electrosynthesis from Nitrate

The electrochemical synthesis of ammonia is highly dependent on the coupling reaction between nitrate and water, for which an electrocatalyst with a multifunctional interface is anticipated to promote the deoxygenation and hydrogenation of nitrate with water. Herein, by engineering the surface of bimetallic Ni/Co-MOFs (NiCoBDC) with hydrogen-substituted graphdiyne (HsGDY), a hybrid nanoarray of NiCoBDC@HsGDY with a multifunctional interface has been achieved toward scale-up of the nitrate-to-ammonia conversion. On the one hand, a partial electron transfers from Ni2+ to the coordinatively unsaturated Co2+ on the surface of NiCoBDC, which not only promotes the deoxygenation of *NO3 on Co2+ but also activates the water-dissociation to *H on Ni2+. On the other hand, the conformal coated HsGDY facilitates both electrons and NO3- ions gathering on the interface between NiCoBDC and HsGDY, which moves forward the rate-determining step from the deoxygenation of *NO3 to the hydrogenation of *N with both *H on Ni2+ and *H2O on Co2+. As a result, such a NiCoBDC@HsGDY nanoarray delivers high NH3 yield rates with Faradaic efficiency above 90% over both wide potential and pH windows. When assembled into a galvanic Zn-NO3- battery, a power density of 3.66 mW cm-2 is achieved, suggesting its potential in the area of aqueous Zn-based batteries.

Facile Synthesis of Hydrogen-Substituted Graphdiyne Powder via Dehalogenative Homocoupling Reaction.

Graphdiyne and its analogs are a series of artificial two-dimensional nanomaterials with sp hybridized carbon atoms, which can be viewed as the insertion of two acetylenic units between adjacent aromatic rings, evenly expanded on a flat surface. Although developed in recent years, new synthetic strategies for graphdiyne analogs are still required. This work proposed a new method to prepare hydrogen-substituted graphdiyne powder via a dehalogenative homocoupling reaction. The polymerization was unanticipated while the initial goal was to synthesize a γ-graphyne analog via Sonogashira cross-coupling reaction. Compared with previous synthetic strategies, the reaction time was conspicuously shortened and the Pd catalyst was inessential. The powder obtained exhibited a porous structure and high electrocatalytic activity in the hydrogen/oxygen evolution reaction, which has the potential for application in electrochemical catalysis. The reported methodology provides an efficient synthetic strategy for large-scale preparation.

Rapid and Reversible Sensing Performance of Hydrogen-Substituted Graphdiyne.

The design of new nanomaterials for rapid and reversible detection of molecules in existence is critical for real-world sensing applications. Current nanomaterial libraries such as carbon nanotubes, graphene, MoS2, and MXene are fundamentally limited by their slow detection speed and small signals; thus, the atomic-level material design of molecular transport pathways and active binding sites must be accompanied. Herein, we fully explore the chemical and physical properties of a hydrogen-substituted graphdiyne (HsGDY) for its molecular sensing properties. This new carbon framework comprises reactive sp carbons in acetylenic linkages throughout the 16.3 Å nanopores and allows for detecting target molecules (e.g., H2) with an exceptionally high sensitivity (ΔR/Rb = 542%) and fast response/recovery time (τ90 = 8 s and τ10 = 38 s) even without any postmodification process. It possesses 2 orders of magnitude higher sensing ability than that of existing nanomaterial libraries. We demonstrate that rapid and reversible molecular binding is attributed to the cooperative interaction with adjacent double sp carbon in the layered nanoporous structure of HsGDY. This new class of carbon framework provides fundamental solutions for nanomaterials in reliable sensor applications that accelerate real-world interfacing.

Novel Two-Dimensional Graphdiyne-Derived Additive for Stable Inverted Perovskite Solar Cells

The defects in perovskite films hinder the improvement of efficiency and long-term device stability of perovskite solar cells (PSCs). Antisolvent additive engineering has been widely applied to effectively reduce perovskite defects and improve the perovskite crystal quality. However, most of the traditional antisolvent-assisted organic additives endure the disadvantages of high volatility, instability, inflammability, high diffusion coefficient, and even toxicity, which hinder the device’s stability for PSCs and raise serious environmental concerns. Herein, in this work, a novel two-dimensional tripolyindene hydrogen-substituted graphdiyne, denoted as DES-O-PHsGY, was synthesized through an easily accessible and biocompatible deep eutectic solvent. XPS measurement demonstrated that DES-O-PHsGY can passivate the lead defects in the perovskite layer. XRD and SEM results verified that DES-O-PHsGY can improve perovskite crystallization. After DES-O-PHsGY was applied as an antisolvent additive for MAPbI3-based PSCs, the maximum open-circuit voltage of devices was increased from 1.079 V to 1.106 V, accompanied by a maximum power conversion efficiency of 20.51% surpassing that without the additive (19.51%). More importantly, the perovskite film with DES-O-PHsGY modification showed satisfactory thermal stability under an 80 °C continuous heating process. This work provides a novel method to prepare effective additives for perovskite defect passivation.

HsGDY on Ni Foam for Loading MoS 2 /Ni 3 S 2 to Enhance the Performance on Lithium–Sulfur Batteries

Lithium–sulfur batteries are considered important devices for the power of movable equipment, but there are still some challenges that limit their applications, such as how to obtain a cathode for high sulfide adsorption and rapid conversion. Here, a new strategy is proposed to enhance the performance of lithium–sulfur batteries by growing 3-dimensional hydrogen-substituted graphdiyne (HsGDY) layers on Ni foam via Glaser cross-coupling reaction to anchor MoS 2 /Ni 3 S 2 , enhancing the conductivity of host material of S. The results show that the 3-dimensional HsGDY framework enables the fast adsorption of lithium polysulfides and the Ni 3 S 2 /MoS 2 performs as the reaction center with a low charge transfer resistance. The charge capacity of Ni@HsGDY/MoS 2 /Ni 3 S 2 cell is up to 1,234.7 mAh·g −1 at the first circle, and the specific capacity keeps 486 mAh·g −1 after 500 cycles at a current density of 2 C. The incorporation of HsGDY into the cathode promotes the adsorption and the conversion of polysulfides, paving a path to obtain lithium–sulfur batteries with high energy density.