2D graphdiyne: an emerging carbon material

Implementation of π-π interaction in AuNPs@GDY to boost the bioelectrocatalysis in enzymatic biofuel cells

The main challenges (sluggish electron transfer, low energy density) hinder the future application of enzymatic biofuel cells (EBFCs), which urgent to take effective measures to solve these issues. In this work, a composite of Au nanoparticles decorated graphdiyne (AuNPs@GDY) is fabricated and employed as the carrier of enzyme (G6PDH), and a mechanism based on π-π interaction of electron transfer is proposed to understand bioelectrocatalysis processes. The results show that the AuNPs@GDY composite exhibits the highest current density among the three materials (GDY, AuNPs, and AuNPs@GDY), which is 3.4 times higher than that of GDY and 2.5 times higher than that of AuNPs. Furthermore, the results reveal that the AuNPs could increase the loading of enzymes and provide more active site for reaction, while GDY provides highly π-conjugated structure and unique sp/sp2-hybridized linkages interface. This work provides new insights to explore a theoretical basis for the development of more efficient bioelectrocatalytic systems.

Comparison of developmental toxicity of graphene oxide and graphdiyne to zebrafish larvae

Graphdiyne (GDY) is a new member of family of carbon-based 2D nanomaterials (NMs), but the environmental toxicity is less investigated compared with other 2D NMs, such as graphene oxide (GO). In this study, we compared with developmental toxicity of GO and GDY to zebrafish larvae. It was shown that exposure of zebrafish embryos from 5 h post fertilization to GO and GDY for up to 5 days decreased hatching rate and induced morphological deformity. Behavioral tests indicated that GO and GDY treatment led to hyperactivity of larvae. However, blood flow velocity was not significantly affected by GO or GDY. RNA-sequencing data revealed that both types of NMs altered gene expression profiles as well as gene ontology terms and KEGG pathways related with metabolism. We further confirmed that the NMs altered the expression of genes related with lipid droplets and autophagy, which may be account for the delayed development of zebrafish larvae. At the same mass concentrations, GO induced comparable or even larger toxic effects compared with GDY, indicating that GDY might be more biocompatible compared with GO. These results may provide novel understanding about the environmental toxicity of GO and GDY in vivo.

Graphdiyne as a Highly Efficient and Neuron-Targeted Photothermal Transducer for in Vivo Neuromodulation

Photothermal modulation of neural activity offers a promising approach for understanding brain circuits and developing therapies for neurological disorders. However, the low neuron selectivity and inefficient light-to-heat conversion of existing photothermal nanomaterials significantly limit their potential for neuromodulation. Here, we report that graphdiyne (GDY) can be developed into an efficient neuron-targeted photothermal transducer for in vivo modulation of neuronal activity through rational surface functionalization. We functionalize GDY with polyethylene glycol (PEG) through noncovalent hydrophobic interactions, followed by antibody conjugation to specifically target the temperature-sensitive transient receptor potential cation channel subfamily V member 1 (TRPV1) on the surface of neural cells. The nanotransducer not only exhibits high photothermal conversion efficiency in the near-infrared region but also shows great TRPV1-targeting capability. This enables photothermal activation of TRPV1, leading to neurotransmitter release in cells and modulation of neural firing in living mice. With its precision and selectivity, the GDY-based transducer provides an innovative avenue for understanding brain function and developing therapeutic strategies for neurodegenerative diseases.

Electrochemically-driven actuators: from materials to mechanisms and from performance to applications

Soft actuators, pivotal for converting external energy into mechanical motion, have become increasingly vital in a wide range of applications, from the subtle engineering of soft robotics to the demanding environments of aerospace exploration. Among these, electrochemically-driven actuators (EC actuators), are particularly distinguished by their operation through ion diffusion or intercalation-induced volume changes. These actuators feature notable advantages, including precise deformation control under electrical stimuli, freedom from Carnot efficiency limitations, and the ability to maintain their actuated state with minimal energy use, akin to the latching state in skeletal muscles. This review extensively examines EC actuators, emphasizing their classification based on diverse material types, driving mechanisms, actuator configurations, and potential applications. It aims to illuminate the complicated driving mechanisms of different categories, uncover their underlying connections, and reveal the interdependencies among materials, mechanisms, and performances. We conduct an in-depth analysis of both conventional and emerging EC actuator materials, casting a forward-looking lens on their trajectories and pinpointing areas ready for innovation and performance enhancement strategies. We also navigate through the challenges and opportunities within the field, including optimizing current materials, exploring new materials, and scaling up production processes. Overall, this review aims to provide a scientifically robust narrative that captures the current state of EC actuators and sets a trajectory for future innovation in this rapidly advancing field.

Steering sp-Carbon Content in Graphdiynes for Enhanced Two-Electron Oxygen Reduction to Hydrogen Peroxide

Compared to sp2-hybridized graphene, graphdiynes (GDYs) composed of sp and sp2 carbon are highly promising as efficient catalysts for electrocatalytic oxygen reduction into oxygen peroxide because of the high catalytic reactivity of the electron-rich sp-carbon atoms. The desired catalytic capacity of GDY, such as catalytic selectivity and efficiency, can theoretically be achieved by strategically steering the sp-carbon contents or the topological arrangement of the acetylenic linkages and aromatic bonds. Herein, we successfully tuned the electrocatalytic activity of GDYs by regulating the sp-to-sp2 carbon ratios with different organic monomer precursors. As the active sp-carbon atoms possess electron-sufficient π orbitals, they can donate electrons to the lowest unoccupied molecular orbital (LUMO) orbitals of O2 molecules and initiate subsequent O2 reduction, GDY with the high sp-carbon content of 50 at % exhibits excellent capability of catalyzing O2 reduction into H2O2. It demonstrates exceptional H2O2 selectivity of over 95.0 % and impressive performance in practical H2O2 production, Faraday efficiency (FE) exceeding 99.0 %, and a yield of 83.3 nmol s-1 cm-2. Our work holds significant importance in effectively steering the inherent properties of GDYs by purposefully adjusting the sp-to-sp2 carbon ratio and highlights their immense potential for research and applications in catalysis and other fields.

Exciton Localization Modulated by Ultradeep Moiré Potential in Twisted Bilayer γ-Graphdiyne

Twisted moiré superlattice is featured with its moiré potential energy, the depth of which renders an effective approach to strengthening the exciton-exciton interaction and exciton localization toward high-performance quantum photonic devices. However, it remains as a long-standing challenge to further push the limit of moiré potential depth. Herein, owing to the pz orbital induced band edge states enabled by the unique sp-C in bilayer γ-graphdiyne (GDY), an ultradeep moiré potential of ∼289 meV is yielded. After being twisted into the hole-to-hole layer stacking configuration, the interlayer coupling is substantially intensified to augment the lattice potential of bilayer GDY up to 475%. The presence of lateral constrained moiré potential shifts the spatial distribution of electrons and holes in excitons from the regular alternating mode to their respective separated and localized mode. According to the well-established wave function distribution of electrons contained in excitons, the AA-stacked site is identified to serve for exciton localization. This work extends the materials systems available for moiré superlattice design further to serial carbon allotropes featured with benzene ring-alkyne chain coupling, unlocking tremendous potential for twistronic-based quantum device applications.

The Accurate Synthesis of a Multiscale Metallic Interface on Graphdiyne

The accurate construction of composite material systems containing graphdiyne (GDY) and other metallic materials has promoted the formation of innovative structures and practical applications in the fields of energy, catalysis, optoelectronics, and biomedicine. To fulfill the practical requirements, the precise formation of multiscale interfaces over a wide range, from single atoms to nanostructures, plays an important role in the optimization of the structural design and properties. The intrinsic correlations between the structure, synthesis process, characteristic properties, and device performance are systematically investigated. This review outlines the current research achievements regarding the controlled formation of multiscale metallic interfaces on GDY. Synthetic strategies for interface regulation, as well as the correlation between the structure and performance, are presented. Furthermore, innovative research ideas for the design and synthesis of functional metal-based materials loaded onto GDY-based substances are also provided, demonstrating the promising application potential of GDY-based materials.

Theoretical Prediction Leads to Synthesize GDY Supported InOx Quantum Dots for CO2 Reduction

The preparation of formic acid by direct reduction of carbon dioxide is an important basis for the future chemical industry and is of great significance. Due to the serious shortage of highly active and selective electrocatalysts leading to the development of direct reduction of carbon dioxide is limited. Herein the target catalysts with high CO2RR activity and selectivity were identified by integrating DFT calculations and high-throughput screening and by using graphdiyne (GDY) supported metal oxides quantum dots (QDs) as the ideal model. It is theoretically predicted that GDY supported indium oxide QDs (i.e., InOx/GDY) is a new heterostructure electrocatalyst candidate with optimal CO2RR performance. The interfacial electronic strong interactions effectively regulate the surface charge distribution of QDs and affect the adsorption/desorption behavior of HCOO* intermediate during CO2RR to achieve highly efficient CO2 conversion. Based on the predicted composition and structure, we synthesized the advanced catalytic system, and demonstrates superior CO2-to-HCOOH conversion performance. The study presents an effective strategy for rational design of highly efficient heterostructure electrocatalysts to promote green chemical production.

Properties, Synthesis and Emerging Applications of Graphdiyne: A Journey Through Recent Advancements

Graphdiyne (GDY) is a new variant of nano-carbon material with excellent chemical, physical and electronic properties. It has attracted wide attention from researchers and industrialists for its extensive role in the fields of optics, electronics, bio-medics and energy. The unique arrangement of sp-sp2 carbon atoms, linear acetylenic linkages, uniform pores and highly conjugated structure offer numerous potentials for further exploration of GDY materials. However, since the material is at its infancy, not much understanding is available regarding its properties, growth mechanism and future applications. Therefore, in this review, readers are guided through a brief discussion on GDY's properties, different synthesis procedures with a special focus on surface functionalization and a list of applications for GDY. The review also critically analyses the advantages and disadvantages of each synthesis route and emphasizes the future scope of the material.

Controlled Growth Lateral/Vertical Heterostructure Interface for Lithium Storage

Artificial heterostructures with structural advancements and customizable electronic interfaces are fundamental for achieving high-performance lithium-ion batteries (LIBs). Here, a design idea for a covalently bonded lateral/vertical black phosphorus (BP)-graphdiyne oxide (GDYO) heterostructure achieved through a facile ball-milling approach, is designed. Lateral heterogeneity is realized by the sp2-hybridized mode P-C bonds, which connect the phosphorus atoms at the edges of BP with the carbon atoms of the terminal acetylene in GDYO. The vertical connection of the heterojunction of BP and GDYO is connected by P-O-C bond. Experimental and theoretical studies demonstrate that BP-GDYO incorporates interfacial and structural engineering features, including built-in electric fields, chemical bond interactions, and maximized nanospace confinement effects. Therefore, BP-GDYO exhibits improved electrochemical kinetics and enhanced structural stability. Moreover, through ex- and in-situ studies, the lithiation mechanism of BP-GDYO, highlighting that the introduction of GDYO inhibits the shuttle/dissolution effect of phosphorus intermediates, hinders volume expansion, provides more reactive sites, and ultimately promotes reversible lithium storage, is clarified. The BP-GDYO anode exhibits lithium storage performance with high-rate capacity and long-cycle stability (602.6 mAh g-1 after 1 000 cycles at 2.0 A g-1). The proposed interfacial and structural engineering is universal and represents a conceptual advance in building high-performance LIBs electrode.

Self-Organized Gradually Single-Atom-Layer of Metal Osmium for an Unprecedented Hydrogen Production from Seawater

Atomic thick two-dimensional (2D) materials with exciting physical, chemical, and electronic properties are gaining increasing attention in next-generation science and technology, showing great promise in catalysis and energy science. However, the precise design and synthesis of efficient catalytic systems based on such materials still face many difficulties, especially in how to control the preparation of structurally determined, highly active, atomic-scale distribution of material systems. Here, we report that a highly active zerovalent osmium single-atom-layer with a thickness of single atom size has been successfully and controllably self-organized on the surface of 2D graphdiyne (GDY) material. Detailed characterizations showed that the incomplete charge transfer effect between the Os atoms and GDY not only stabilized the catalytic system but also improved the intrinsic activity, making the Gibbs free energy reach the best and resulting in remarkable performance with a small overpotential of 49 mV at 500 mA cm-2, large specific j0 of 18.6 mA cm-2, and turnover frequency of 3.89 H2 s-1 at 50 mV. In addition, the formation of sp-C-Os bonds guarantees the high long-term stability of 800 h at a large current density of 500 mA cm-2 in alkaline simulated seawater.

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.

Surface atom knockout for the active site exposure of alloy catalyst

The fine regulation of catalysts by the atomic-level removal of inactive atoms can promote the active site exposure for performance enhancement, whereas suffering from the difficulty in controllably removing atoms using current micro/nano-scale material fabrication technologies. Here, we developed a surface atom knockout method to promote the active site exposure in an alloy catalyst. Taking Cu3Pd alloy as an example, it refers to assemble a battery using Cu3Pd and Zn as cathode and anode, the charge process of which proceeds at about 1.1 V, equal to the theoretical potential difference between Cu2+/Cu and Zn2+/Zn, suggesting the electricity-driven dissolution of Cu atoms. The precise knockout of Cu atoms is confirmed by the linear relationship between the amount of the removed Cu atoms and the battery cumulative specific capacity, which is attributed to the inherent atom-electron-capacity correspondence. We observed the surface atom knockout process at different stages and studied the evolution of the chemical environment. The alloy catalyst achieves a higher current density for oxygen reduction reaction compared to the original alloy and Pt/C. This work provides an atomic fabrication method for material synthesis and regulation toward the wide applications in catalysis, energy, and others.

Graphdiyne marries PEDOT:PSS to form high-stable heterostructure from 2-unstable components toward ultra-low detection limit of uric acid detection in sweat

PEDOT

PSS has been used as a biomimetic uric acid (UA) sensor but suffers from unfortunate low detection limit (LOD), narrow detection range and poor stability. Herein, we get graphdiyne (GDY) marry PEDOT:PSS to create a very stable GDY@PEDOT:PSS heterostructure for a biomimetic UA sensor, which accomplishes the lowest LOD (6 nM), the widest detection range (0.03 μM-7 mM) and the longest stability (98.1% for 35 days) among the related UA sensors. The sensor was successfully used to in situ real-time detection of  UA in sweat. The enhancement mechanisms of the sensor were investigated, and results discover that C≡C of GDY and C = C of PEDOT:PSS can cross-link each other by π-π interactions, making not only the former strongly resistant against oxidation deterioration, but also causes the latter to efficiently prevent water swelling of polymer for poor conductivity, thereby leading to high stability from both components. While the stabilized heterostructure can also offer more active sites by enhanced absorption of UA via π-π interactions for highly sensitive detection of UA. This work holds great promise for a practical sweat UA sensor while providing scientific insight to design a stable and electrocatalytically active structure from two unstable components.

Graphdiyne/metal oxide hybrid materials for efficient energy and environmental catalysis

Graphdiyne (GDY)-based materials, owing to their unique structure and tunable electronic properties, exhibit great potential in the fields of catalysis, energy, environmental science, and beyond. In particular, GDY/metal oxide hybrid materials (GDY/MOs) have attracted extensive attention in energy and environmental catalysis. The interaction between GDY and metal oxides can increase the number of intrinsic active sites, facilitate charge transfer, and regulate the adsorption and desorption of intermediate species. In this review, we summarize the structure, synthesis, advanced characterization, small molecule activation mechanism and applications of GDY/MOs in energy conversion and environmental remediation. The intrinsic structure-activity relationship and corresponding reaction mechanism are highlighted. In particular, the activation mechanisms of reactant molecules (H2O, O2, N2, etc.) on GDY/MOs are systemically discussed. Finally, we outline some new perspectives of opportunities and challenges in developing GDY/MOs for efficient energy and environmental catalysis.

Direct solar energy conversion on zinc-air battery

A concept of solar energy convertible zinc-air battery (SZAB) is demonstrated through rational design of an electrode coupled with multifunction. The multifunctional electrode is fabricated using nitrogen-substituted graphdiyne (N-GDY) with large π-conjugated carbonous network, which can work as photoresponsive bifunctional electrocatalyst, enabling a sunlight-promoted process through efficient injection of photoelectrons into the conduction band of N-GDY. SZAB enables direct conversion and storage of solar energy during the charging process. Such a battery exhibits a lowered charge voltage under illumination, corresponding to a high energy efficiency of 90.4% and electric energy saving of 30.3%. The battery can display a power conversion efficiency as high as 1.02%. Density functional theory calculations reveal that the photopromoted oxygen evolution reaction kinetics originates from the transition from the alkyne bonds to double bonds caused by the transfer of excited electrons, which changes the position of highest occupied molecular orbital and lowest unoccupied molecular orbital, thus greatly promoting the formation of intermediates to the conversion process. Our findings provide conceptual and experimental confirmation that batteries are charged directly from solar energy without the external solar cells, providing a way to manufacture future energy devices.

Microcrystalline Nanofiber Electrode with Adaptive Intrinsic Structure and Microscopic Interface

A strategy of microcrystalline aggregation is proposed to fabricate energy storage electrode with outstanding capacity and stability. Carbon-rich electrode (BDTG) functionalized with benzo[1,2-b:4,5-b']dithiophene units and butadiyne segments are prepared. The linear conjugate chains pack as microcrystalline nanofibers on nanoscale, which further aggregates to form a porous interpenetrating network. The microcrystalline aggregation feature of BDTG exhibit stable structure during long cycling test, revealing the following advantage in structure and property. The stretchable butadiyne linker facilitates reversible adsorption and desorption of Li with the aid of adjacent sulfur heteroatom. The alkyne-alkene transition exhibits intrinsic structural stability of microcrystalline region in BDTG electrodes. Meanwhile, alkynyl groups and sulfur heteroatoms on the surface of BDTG nanofibers participate in the formation of microscopic interface, providing a stable interfacial contact between BDTG electrodes and adjacent electrolyte. As a proof-of-concept, BDTG-based electrode shows high capacity (1430 mAh g-1 at 50 mA g-1) and excellent cycle performance (8000 cycles under 5 A g-1) in half-cell of lithium-ion batteries, and a reversible capacity of 120 mAh g-1 is obtained under the current density of 2 C in full-cell. This work shows microcrystalline aggregation is beneficial to realize adaptive intrinsic structure and interface contact during the charge-discharge process.

Fabrication of Zn-Air Battery with High Output Capacity Under Ultra-Large Current

Zn-air battery (ZAB) is advocated as a more viable option in the new-energy technology. However, the limited-output capacity at a high current density impedes the driving range in power batteries substantially. Here, a novel heterojunction-based graphdiyne (GDY) and Ag29Cu7 alloy quantum dots (Ag29Cu7 QDs/GDY) for constructing a high-performance aqueous ZAB are fabricated. The as-fabricated ZAB achieves discharge at up to 100 mA cm-2 (the highest value ever reported) along with a remarkable output specific capacity of 786.2 mAh g-1 Zn, which is mainly benefitted from the binary-synergistic effect toward a stable triple-phase interface for air electrode induced by the Ag29Cu7 QDs and GDY in harsh base, together with the decreasing reaction energy barrier and polarization. The results outperform the superior reports discharging at low current and will bring breakthrough progress toward the practical applications of ZAB on large power supply facilities.

A sandwich-type dual-mode biosensor based on graphdiyne and DNA nanoframework for ultra-sensitive detection of CD142 gene

Thalassemia is a globally prevalent single-gene blood disorder, with nearly 7% of the world's population being carriers. Therefore, the development of specific and sensitive methods for thalassemia detection holds significant importance. Herein, a sandwich-type electrochemical/colorimetric dual-mode biosensor is developed based on gold nanoparticles (AuNPs)/graphdiyne (GDY) and DNA nanoframeworks for ultra-sensitive detection of CD142 gene associated with sickle cell anemia. Utilizing AuNPs/GDY as the substrate electrode, the fabricated sandwiched DNA nanoframework not only improves selectivity but also introduces numerous signal probes to further amplify the output signal. In the electrochemical mode, glucose oxidase catalyzes the oxidation of glucose, generating electrons that are transferred to the biocathode for a reduction reaction, resulting in an electric signal proportional to the target concentration. In the colorimetric mode, glucose oxidase catalyzes the generation of H2O2 from glucose, and with the aid of horseradish peroxidase, H2O2 oxidizes 3,3',5,5'-tetramethylbenzidine to produce a colored product, enabling colorimetric detection of the target. The dual-mode biosensor demonstrates a detection range of 0.0001-100 pM in the electrochemical mode and a detection range of 0.0001-10,000 pM in the colorimetric mode. The detection limit in the electrochemical mode is determined to be 30.4 aM (S/N=3), while in the colorimetric mode is of 35.6 aM (S/N=3). This dual-mode detection achieves ultra-sensitive detection of CD142, demonstrating broad prospects for application.

New Carbon Materials for Multifunctional Soft Electronics

Soft electronics are garnering significant attention due to their wide-ranging applications in artificial skin, health monitoring, human-machine interaction, artificial intelligence, and the Internet of Things. Various soft physical sensors such as mechanical sensors, temperature sensors, and humidity sensors are the fundamental building blocks for soft electronics. While the fast growth and widespread utilization of electronic devices have elevated life quality, the consequential electromagnetic interference (EMI) and radiation pose potential threats to device precision and human health. Another substantial concern pertains to overheating issues that occur during prolonged operation. Therefore, the design of multifunctional soft electronics exhibiting excellent capabilities in sensing, EMI shielding, and thermal management is of paramount importance. Because of the prominent advantages in chemical stability, electrical and thermal conductivity, and easy functionalization, new carbon materials including carbon nanotubes, graphene and its derivatives, graphdiyne, and sustainable natural-biomass-derived carbon are particularly promising candidates for multifunctional soft electronics. This review summarizes the latest advancements in multifunctional soft electronics based on new carbon materials across a range of performance aspects, mainly focusing on the structure or composite design, and fabrication method on the physical signals monitoring, EMI shielding, and thermal management. Furthermore, the device integration strategies and corresponding intriguing applications are highlighted. Finally, this review presents prospects aimed at overcoming current barriers and advancing the development of state-of-the-art multifunctional soft electronics.

Construction of n-type homogeneous to improve interfacial carrier transfer for enhanced photoelectrocatalytic hydrolysis

Photoelectrocatalyzed hydrogen production plays an important role in the path to carbon neutrality. The construction of heterojunctions provides an ideal example of an oxygen precipitation reaction. In this work, the performance of the n-n type heterojunction CeBTC@FeBTC/NIF in the photoelectronically coupled catalytic oxygen evolution reaction (OER) reaction is presented. The efficient transfer of carriers between components enhances the catalytic activity. Besides, the construction of heterojunctions optimizes the energy level structure and increases the absorption of light, and the microstructure forms holes with a blackbody effect that also enhances light absorption. Consequently, CeBTC@FeBTC/NIF has excellent photoelectric coupling catalytic properties and requires an overpotential of only 300 mV to drive a current density of 100 mA cm-2 under illumination. More importantly, the n-n heterojunction was found to be effective in enhancing charge and photogenerated electron migration by examining the carrier density of each component and carrier diffusion at the interface.

Proposing TODD-graphene as a novel porous 2D carbon allotrope designed for superior lithium-ion battery efficiency

The category of 2D carbon allotropes has gained considerable interest due to its outstanding optoelectronic and mechanical characteristics, which are crucial for various device applications, including energy storage. This study uses density functional theory calculations, ab initio molecular dynamics (AIMD), and classical reactive molecular dynamics (MD) simulations to introduce TODD-Graphene, an innovative 2D planar carbon allotrope with a distinctive porous arrangement comprising 3-8-10-12 carbon rings. TODD-G exhibits intrinsic metallic properties with a low formation energy and stability in thermal and mechanical behavior. Calculations indicate a substantial theoretical capacity for adsorbing Li atoms, revealing a low average diffusion barrier of 0.83 eV. The metallic framework boasts excellent conductivity and positioning TODD-G as an active layer for superior lithium-ion battery efficiency. Charge carrier mobility calculations for electrons and holes in TODD-G surpass those of graphene. Classical reactive MD simulation results affirm its structural integrity, maintaining stability without bond reconstructions at 2200 K.

Exploring the impact of stress on the electronic structure and optical properties of graphdiyne nanoribbons for advanced optoelectronic applications

Graphdiyne (GDY), a two-dimensional carbon material with sp- and sp2-hybridization, is recognized for its unique electronic properties and well-dispersed porosity. Its versatility has led to its use in a variety of applications. The precise control of this material's properties is paramount for its effective utilization in nano-optical devices. One effective method of regulation, which circumvents the need for additional disturbances, involves the application of external stress. This technique provides a direct means of eliciting changes in the electronic characteristics of the material. For instance, when subjected to uniaxial stress, electron transfer occurs at the triple bond. This results in an armchair-edged graphdiyne nanoribbon (A(3)-GDYNR) with a planar width of 2.07 nm, which exhibits a subtle plasmon effect at 500 nm. Conversely, a zigzag-edged graphdiyne nanoribbon (Z(3)-GDYNR) with a planar width of 2.86 nm demonstrates a pronounced plasmon effect within the 250-1200 nm range. This finding suggests that the zigzag nanoribbon surpasses the armchair nanoribbon in terms of its plasmon effect. First principles calculations and ab initio molecular dynamics further confirmed that under applied stress Z(3)-GDYNR exhibits less deformation than A(3)-GDYNR, indicating superior stability. This work provides the necessary theoretical basis for understanding graphene nanoribbons (GDYNRs).

Enhanced uranium extraction from seawater: from the viewpoint of kinetics and thermodynamics

Uranium extraction from seawater (UES) is recognized as one of the seven pivotal chemical separations with the potential to revolutionize global paradigms. The forthcoming decade is anticipated to witness a surge in UES, driven by escalating energy demands. The oceanic reservoirs, possessing uranium quantities approximately 1000-fold higher than terrestrial mines, present a more sustainable and environmentally benign alternative. Empirical evidence from historical research indicates that adsorption emerges as the most efficacious process for uranium recovery from seawater, considering operational feasibility, cost-effectiveness, and selectivity. Over the years, scientific exploration has led to the development of a plethora of adsorbents with superior adsorption capacity. It would be efficient to design materials with a deep understanding of the adsorption from the perspective of kinetics and thermodynamics. Here, we summarize recent advancements in UES technology and the contemporary challenges encountered in this domain. Furthermore, we present our perspectives on the future trajectory of UES and finally offer our insights into this subject.

RuOx Quantum Dots Loaded on Graphdiyne for High-Performance Lithium-Sulfur Batteries

Here, a strategy to strengthen d-p orbital hybridization by fabricating π backbonding in the catalyst for efficient lithium polysulfides (LiPSs) conversion is reported. A special interface structure of RuOx quantum dots (QDs) anchored on graphdiyne (GDY) nanoboxes (RuOx QDs/GDY) is prepared to enable strong Ru-to-alkyne π backdonation, which effectively regulates the d-electron structures of Ru centers to promote the d-p orbital hybridization between the catalyst and LiPSs and significantly boosts the catalytic performance of RuOx QDs/GDY. The strong affinity with Li ions and fast Li-ion diffusion of RuOx QDs/GDY also enable ultrastable Li metal anodes. Thus, S@RuOx QDs/GDY cathodes exhibit excellent cycling performance under harsh conditions, and Li@RuOx QDs/GDY anodes show an ultralong cycling life over 8800 h without Li dendrite growth. Lithium-sulfur (Li-S) full cells with S@RuOx QDs/GDY cathodes and Li@RuOx QDs/GDY anodes can deliver an impressive areal capacity of 17.8 mA h cm-2 and good cycling stability under the practical conditions of low negative-to-positive electrode capacity (N/P) ratio (N/P = 1.4), lean electrolyte (E/S = 3 µL mg-1 ), and high S mass loading (15.4 mg cm-2 ).

Controlled Growth of Metal Atom Arrays on Graphdiyne for Seawater Oxidation

Advanced atomic-level heterointerface engineering provides a promising method for the preparation of next-generation catalysts. Traditional carbon-based heterointerface catalytic performance rely heavily on the undetermined defects in complex and demanding preparation processes, rendering it impossible to control the catalytic performance. Here, we present a general method for the controlled growth of metal atom arrays on graphdiyne (GDY/IrCuOx), and we are surprised to find strong heterointerface strains during the growth. We successfully controlled the thickness of GDY to regulate the heterointerface metal atoms and achieved compressive strain at the interface. Experimental and density functional theory calculation results show that the unique incomplete charge transfer between GDY and metal atoms leads to the formation of strong interactions and significant heterointerface compressive strain between GDY and IrCuOx, which results in high oxidation performances with 1000 mA cm-2 at a low overpotential of 283 mV and long-term stability at large current densities in alkaline simulated seawater. We anticipate that this finding will contribute to construction of high-performance heterogeneous interface structures, leading to the development of new generation of GDY-based heterojunction catalysts in the field of catalysis for future promising performance.

Emerging Two-Dimensional Carbonaceous Materials for Electrocatalytic Energy Conversions: Rational Design of Active Structures through High-Temperature Chemistry

Electrochemical energy conversion and storage technologies involving controlled catalysis provide a sustainable way to handle the intermittency of renewable energy sources, as well as to produce green chemicals/fuels in an ecofriendly manner. Core to such technology is the development of efficient electrocatalysts with high activity, selectivity, long-term stability, and low costs. Here, two-dimensional (2D) carbonaceous materials have emerged as promising contenders for advancing the chemistry in electrocatalysis. We review the emerging 2D carbonaceous materials for electrocatalysis, focusing primarily on the fine engineering of active structures through thermal condensation, where the design, fabrication, and mechanism investigations over different types of active moieties are summarized. Interestingly, all the recipes creating two-dimensionality on the carbon products also give specific electrocatalytic functionality, where the special mechanisms favoring 2D growth and their consequences on materials functionality are analyzed. Particularly, the structure-activity relationship between specific heteroatoms/defects and catalytic performance within 2D metal-free electrocatalysts is highlighted. Further, major challenges and opportunities for the practical implementation of 2D carbonaceous materials in electrocatalysis are summarized with the purpose to give future material design guidelines for attaining desirable catalytic structures.

Controllable Assembly of Highly Oxidized Cobalt on Graphdiyne Surface for Efficient Conversion of Nitrogen into Nitric Acid

The manufacture of nitric acid (HNO3 ) consumes large amounts of energy and causes serious environmental pollution. Electrochemical synthesis is regarded as a key way to eliminate carbon emissions from the chemicals industry. The selective electrosynthesis of HNO3 from nitrogen was achieved by controllable assembly of cobalt metal on graphdiyne surface using a powerful tool of electrochemistry at ambient conditions. As an advanced material, graphdiyne (GDY) has a large conjugated structure on its surface and is rich in sp-C triple bond skeleton, which can achieve strong interaction with metal atoms, resulting in incomplete charge transfer between graphdiyne and cobalt atoms. The experimental and theoretical calculation results show that the highly oxidized cobalt on graphdiyne (HOCo/GDY) can selectively and efficiently activate and convert the nitrogen into the key intermediate *NO, which promotes the efficient overall conversion performance of nitrogen to nitric acid. Thus, the highest nitric acid yield (192.0 μg h-1  mg-1 ) and Faradaic efficiency (21.5 %) were achieved at low potentials.

Exploring the Fate of Copper Ions in the Synthesis of Graphdiyne

Copper is a crucial catalyst in the synthesis of graphdiyne (GDY). However, as catalysts, the final fate of the copper ions has hardly been concerned, which are usually treated as impurities. Here, it is observed that after simple washing with water and ethanol, GDY still contains a certain amount of copper ions, and demonstrated that the copper ions are adsorbed at the atomic layers of GDY. Furthermore, we transformed in situ the copper ions into ultrathin Cu nanocrystals, and the obtained Cu/GDY hybrids can be generally converted into a series of metal/GDY hybrid materials, such as Ag/GDY, Au/GDY, Pt/GDY, Pd/GDY, and Rh/GDY. The Cu/GDY hybrids exhibit extraordinary surface enhanced Raman scattering effect and can be applied in pollutant efficient enrichment and detection.

Self-Assembly of Wheel-Shaped Nanographdiynes and Self-Template Growth of Graphdiyne

Graphdiyne (GDY) multilayers show stacking-style-dependent physical properties; thus, controlling the stacking style of nanostructures is crucial for utilizing their electrical, optical, and transport properties in electro-optical devices. Herein, we report the assemblies of nanographdiynes decorated with substituents with different steric hindrances to adjust the stacking style. We show that the π-stacked aggregates were influenced by peripheral substituents and the substrate. Steric hexaterphenyl-substituted nanoGDY scaffolds led to dimer structures stacked in the AB-3 configuration with a twist angle of 26.01° or the AB-1 configuration with an in-plane shift along one diyne link. With the interval replacement of steric substituents with long C12 alkyl chains, nanoGDYs were stacked in the AB-2 configuration to decrease the steric congestion, eventually leading to one-dimensional (1D) nanofibrous aggregates. Self-assembly in the presence of substrates can result in ABC-stacked nanoGDYs, which endowed us with the possibility of using nanoGDY as the template for GDY growth in a homogeneous reaction. High-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and near-infrared-ultraviolet-visible (NIR-UV-vis) absorption spectroscopy indicate that the crystalline GDY prepared in this way is a 1.18 eV bandgap semiconductor.

Nanocarbon-based sensors for the structural health monitoring of smart biocomposites

Structural health monitoring (SHM) is a critical aspect of ensuring the safety and durability of smart biocomposite materials used as multifunctional materials. Smart biocomposites are composed of renewable or biodegradable materials and have emerged as eco-friendly alternatives of traditional non-biodegradable glass fiber-based composite materials. Although biocomposites exhibit fascinating properties and many desirable traits, real-time and early stage SHM is the most challenging issue to enable their long-term use. Smart biocomposites are integrated with sensors for in situ identification of the progress of damage and composite failure. The sensitivity of such smart biocomposites is a key functionality, which can be tuned by the introduction of an appropriate filler. In particular, nanocarbons hold promising potential to be incorporated in SHM applications of biocomposites. This review focused on the potential applications of nanocarbons in SHM of biocomposites. The aspects related to fabrication techniques and working mechanism of sensors are comprehensively discussed. Furthermore, their unique mechanical and electrical properties and sustainable nature ensure seamless integration into biocomposites, allowing for real-time monitoring without compromising the material's properties. These sensors offer multi-parameter sensing capabilities, such as strain, pressure, humidity, temperature, and chemical exposure, allowing a comprehensive assessment of biocomposite health. Additionally, their durability and longevity in harsh conditions, along with wireless connectivity options, provide cost-effective and sustainable SHM solutions. As research in this field advances, ongoing efforts seek to enhance the sensitivity and selectivity of these sensors, optimizing their performance for real-world applications. This review highlights the significant advances, ongoing efforts to enhance the sensitivity and selectivity, and performance optimization of nanocarbon-based sensors along with their working mechanism in the field of SHM for smart biocomposites. The key challenges and future research perspectives facing the conversion of nanocarbons to smart biocomposites are also displayed.

Graphyne and graphdiyne nanoribbons: from their structures and properties to potential applications

Graphyne (GY) and graphdiyne (GDY) have properties including unique sp- and sp2-hybrid carbon atomic structures, natural non-zero band gaps, and highly conjugated π electrons. GY and GDY have good application prospects in many fields, including catalysis, solar cells, sensors, and modulators. Under the influence of the boundary effect and quantum size effect, quasi-one-dimensional graphyne nanoribbons (GYNRs) and graphdiyne nanoribbons (GDYNRs) show novel physical properties. The various structures available give GYNRs and GDYNRs greater band structure and electronic properties, and their excellent physical and chemical properties differ from those of two-dimensional GY and GDY. However, the development of GYNRs and GDYNRs still faces problems, including issues with accurate synthesis, advanced structural characterization, the structure-performance correlation of materials, and potential applications. In this review, the structures and physical properties of quasi-one-dimensional GYNRs and GDYNRs are reviewed, their advantages and disadvantages are summarized, and their potential applications are highlighted. This review provides a meaningful basis and research foundation for the design and development of high-performance materials and devices based on GYNRs and GDYNRs in the field of energy.

Molecular Understanding of Charging Dynamics in Supercapacitors with Porous Electrodes and Ionic Liquids

Porous electrodes and ionic liquids could significantly enhance the energy storage of supercapacitors. However, they may reduce the charging dynamics and power density due to the nanoconfinement of porous electrodes and the high viscosity of ionic liquids. A comprehensive understanding of the charging mechanism in porous supercapacitors with ionic liquids provides a crucial theoretical foundation for their design optimization. Here, we review the progress of molecular simulations of the charging dynamics in supercapacitors consisting of porous electrodes and ionic liquids. We highlight and delve into the breakthroughs in the ion transport and charging mechanism for electrodes with subnanometer pores and realistic porous structures. We also discuss future directions for the charging dynamics of supercapacitors.

Precise Preparation of Triarylboron-Based Graphdiyne Analogues for Gas Separation

A series of triarylboron-based graphdiyne analogues (TAB-GDYs) with tunable pore size were prepared through copper mediated coupling reaction. The elemental composition, chemical bond, morphology of TAB-GDYs were well characterized. The crystallinity was confirmed by selected area electron diffraction (SAED) and stacking modes were studied in combination with high resolution transmission electron microscope (HRTEM) and structure simulation. The absorption and desorption isotherm revealed relatively high specific surface area of these TAB-GDYs up to 788 m2  g-1 for TMTAB-GDY, which decreased as pore size enlarged. TAB-GDYs exhibit certain selectivity for CO2 /N2 (21.9), CO2 /CH4 (5.3), CO2 /H2 (41.8) and C2 H2 /CO2 (2.3). This work has developed a series of boron containing two-dimensional frameworks with clear structures and good stability, and their tunable pore sizes have laid the foundation for future applications in the gas separation field.

Graphdiyne chelated AuNPs for ultrasensitive electrochemical detection of tyrosine

Tyrosine (Tyr) is a kind of amino acid that can regulate emotions and stimulate the nervous system, and it is of great importance to realize its ultrasensitive detection. A unique material of graphdiyne chelated AuNPs (GDY@AuNPs) is designed and developed to realize high-performance electrochemical sensing of Tyr. GDY promotes the absorption of Tyr via π-π interaction, and its CC strongly chelates with AuNPs for greatly improved sensitivity. GDY@AuNPs delivers a sensitivity of up to 181.2 μA mM-1 cm-2 and a wide range of 0.1-600 μM, among the best for carbon or AuNPs-based materials for the detection of Tyr. It demonstrates the accurate detection of Tyr in human sweat for potential practical applications.

Targeted Spin-State Regulation to Boost Oxygen Reduction Reaction

Catalytic reactions are known to be significantly affected by spin states and their variations during reaction processes, yet the mechanisms behind them remain not fully understood, thus preventing the rational optimization of catalysis. Here, we explore the relationship between the spin states of active sites and their catalytic performance, taking the oxygen reduction reaction as an example. We demonstrate that the catalytic performance is spin-state-dependent and can be improved by adjusting spin states during the catalytic process. To this end, we further investigate the possibility of altering the spin states of transition metals through the application of external fields, such as adsorbed species. By studying the influence of the strength of adsorbed ligands on spin states and its impact on catalytic performance, our results show that optimal catalytic performance is achieved when the strength of the external field is neither too strong nor too weak, forming a volcano-like relationship between the catalytic performance and the external field strength. Our findings can have far-reaching implications for the rational design of high-performance catalysis.

Interface engineering of transition metal-nitrogen-carbon by graphdiyne for boosting the oxygen reduction/evolution reactions: A computational study

Exploring high-efficiency electrocatalysts to boost the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is pivotal to the large-scale applications for clean and renewable energy technologies, such as fuel cells, water splitting, and metal-air batteries. Herein, by means of density functional theory (DFT) computations, we proposed a strategy to modulate the catalytic activity of transition metal-nitrogen-carbon catalysts through their interface engineering with graphdiyne (TMNC/GDY). Our results revealed that these hybrid structures exhibit good stability and excellent electrical conductivity. Especially, CoNC/GDY was identified as a promising bifunctional catalyst for ORR/OER with rather low overpotentials in acidic conditions according to the constant-potential energy analysis. Moreover, the volcano plots were established to describe the activity trend of the ORR/OER on TMNC/GDY using the adsorption strength of the oxygenated intermediates. Remarkably, the d-band center and charge transfer of the TM active sites can be utilized to correlate the ORR/OER catalytic activity and their electronic properties. Our findings not only suggested an ideal bifunctional oxygen electrocatalyst, but also provided a useful strategy to obtain highly efficient catalysts by interface engineering of two-dimensional heterostructures.

A Surface Matrix of Au NPs Decorated Graphdiyne for Multifunctional Laser Desorption/Ionization Mass Spectrometry

The development of the valid strategy to enhance laser desorption/ionization efficiency gives rise to widespread concern in surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) technology. Herein, a hybrid of Au NP-decorated graphdiyne (Au/GDY) was fabricated and employed as the SALDI-MS matrix for the first time, and a mechanism based on photothermal and photochemical energy conversions was proposed to understand LDI processes. Given theoretical simulations and microstructure characterizations, it was revealed that the formation of a coupled thermal field and internal electric field endow the as-prepared Au/GDY matrix with superior desorption and ionization efficiency, respectively. Moreover, laser-induced matrix ablation introduced strain and defect level into the Au/GDY hybrid, suppressing the recombination of charge carriers and thereby facilitating analyte ionization. The optimized Au/GDY matrix allowed for reliable detection of trace sulfacetamide and visualization of exogenous/endogenous components in biological tissues. This work offers an integrated solution to promote LDI efficiency based on collaborative photothermal conversion and internal electric field, and may inspire the design of novel semiconductor-based surface matrices.

Highly Selective Electrocatalytic Olefin Hydrogenation in Aqueous Solution

Selective hydrogenation of olefins with water as the hydrogen source at ambient conditions is still a big challenge in the field of catalysis. Herein, the electrocatalytic hydrogenation of purely aliphatic and functionalized olefins was achieved by using graphdiyne based copper oxide quantum dots (Cux O/GDY) as cathodic electrodes and water as the hydrogen source, with high activity and selectivity in aqueous solution at high current density under ambient temperature and pressure. In particular, the sp-/sp2 -hybridized graphdiyne catalyst allows the selective hydrogenation of cis-trans isomeric olefins. The chemical and electronic structure of the GDY results in the incomplete charge transfer between GDY and Cu atoms to optimize the adsorption/desorption of the reaction intermediates and results in high reaction selectivity and activity for hydrogenation reactions.

Dual-Interface Engineering in Perovskite Solar Cells with 2D Carbides

Passivating the interfaces between the perovskite and charge transport layers is crucial for enhancing the power conversion efficiency (PCE) and stability in perovskite solar cells (PSCs). Here we report a dual-interface engineering approach to improving the performance of FA0.85 MA0.15 Pb(I0.95 Br0.05 )3 -based PSCs by incorporating Ti3 C2 Clx Nano-MXene and o-TB-GDY nanographdiyne (NanoGDY) into the electron transport layer (ETL)/perovskite and perovskite/ hole transport layer (HTL) interfaces, respectively. The dual-interface passivation simultaneously suppresses non-radiative recombination and promotes carrier extraction by forming the Pb-Cl chemical bond and strong coordination of π-electron conjugation with undercoordinated Pb defects. The resulting perovskite film has an ultralong carrier lifetime exceeding 10 μs and an enlarged crystal size exceeding 2.5 μm. A maximum PCE of 24.86 % is realized, with an open-circuit voltage of 1.20 V. Unencapsulated cells retain 92 % of their initial efficiency after 1464 hours in ambient air and 80 % after 1002 hours of thermal stability test at 85 °C.

Defect Rich Structure Activated 3D Palladium Catalyst for Methanol Oxidation Reaction

Controlling the structure and properties of catalysts through atomic arrangement is the source of producing a new generation of advanced catalysts. A highly active and stable catalyst in catalytic reactions strongly depends on an ideal arrangement structure of metal atoms. We demonstrated that the introduction of the defect-rich structures, low coordination number (CN), and tensile strain in three-dimensional (3D) urchin-like palladium nanoparticles through chlorine bonded with sp-C in graphdiyne (Pd-UNs/Cl-GDY) can regulate the arrangement of metal atoms in the palladium nanoparticles to form a special structure. In situ Fourier infrared spectroscopy (FTIR) and theoretical calculation results show that Pd-UNs/Cl-GDY catalyst is beneficial to the oxidation and removal of CO intermediates. The Pd-UNs/Cl-GDY for methanol oxidation reaction (MOR) that display high current density (363.6 mA cm-2 ) and mass activity (3.6 A mgPd -1 ), 12.0 and 10.9 times higher than Pd nanoparticles, respectively. The Pd-UNs/Cl-GDY catalyst also exhibited robust stability with still retained 95 % activity after 2000 cycles. A defects libraries of the face-centered cubic and hexagonal close-packed crystal catalysts (FH-NPs) were synthesized by introducing chlorine in graphdiyne. Such defect-rich structures, low CN, and tensile strain tailoring methods have opened up a new way for the catalytic reaction of MOR.

Porous carbon nanosheets derived from two-dimensional Fe-MOF for simultaneous voltammetric sensing of dopamine and uric acid

It is of great significance for electrochemical sensors to simultaneously detect dopamine (DA) and uric acid (UA) related to biological metabolism. In this work, two-dimensional (2D) porous carbon nanosheets (CNS) was prepared as electrocatalysts to improve the sensitivity, the selectivity, and the detection limit of the simultaneous detection. First, 2D amorphous iron-metal organic frameworks (Fe-MOF) was synthesized with Fe3+and terephthalic acid via a facile wet chemistry method at room temperature. And then, CNS was prepared by pyrolysis and pickling of Fe-MOF. CNS had large specific surface area, good electrical conductivity and lots of carbon defects. The response currents of the CNS modified electrode was larger than those of the control electrodes in the simultaneous determination. The simultaneous determination was measured via differential pulse voltammetry to reduce the effect of capacitive currents on quantitative analysis. The CNS modified electrodes showed high sensitivity and low detection limit for the simultaneous detection of DA and UA. The modified electrodes have been successfully used to detect DA and UA in normal human serum.

State, synthesis, perspective applications, and challenges of Graphdiyne and its analogues: A review of recent research

Carbon materials technology provides the possibility of synthesizing low-cost, outstanding performance replacements to noble-metal catalysts for long-term use. Graphdiyne (GDY) is a carbon allotrope with an extremely thin atomic thickness. It consists of carbon elements, that are hybridized with both sp. and sp2, resulting in a multilayered two-dimensional (2D) configuration. Several functional models suggest, that GDY contains spontaneously existing band structure with Dirac poles. This is due to the non-uniform interaction among carbon atoms, which results from various fusions and overlapping of the 2pz subshell. Unlike other carbon allotropes, GDY has Dirac cone arrangements, that in turn give it inimitable physiochemical characteristics. These properties include an adjustable intrinsic energy gap, high speeds charging transport modulation efficiency, and exceptional conductance. Many scientists are interested in such novel, linear, stacked materials, including GDY. As a result, organized synthesis of GDY has been pursued, making it one of the first synthesized GDY materials. There are several methods to manipulate the band structure of GDY, including applying stresses, introducing boron/nitrogen loading, utilizing nanowires, and hydrogenations. The flexibility of GDY can be effectively demonstrated through the formation of nano walls, nanostructures, nanotube patterns, nanorods, or structured striped clusters. GDY, being a carbon material, has a wide range of applications owing to its remarkable structural and electrical characteristics. According to subsequent research, the GDY can be utilized in numerous energy generation processes, such as electrochemical water splitting (ECWS), photoelectrochemical water splitting (PEC WS), nitrogen reduction reaction (NRR), overall water splitting (OWS), oxygen reduction reaction (ORR), energy storage materials, lithium-Ion batteries (LiBs) and solar cell applications. These studies suggested that the use of GDY holds significant potential for the development and implementation of efficient, multimodal, and intelligent catalysts with realistic applications. However, the limitation of GDY and GDY-based composites for forthcoming studies are similarly acknowledged. The objective of these studies is to deliver a comprehensive knowledge of GDY and inspire further advancement and utilization of these unique carbon materials.

Graphdiyne-Based Multiscale Catalysts for Ammonia Synthesis

Graphdiyne, a sp/sp2 -cohybridized two-dimensional all- carbon material, has many unique and fascinating properties of alkyne-rich structures, large π conjugated system, uniform pores, specific unevenly-distributed surface charge, and incomplete charge transfer properties provide promising potential in practical applications including catalysis, energy conversion and storage, intelligent devices, life science, photoelectric, etc. These superior advantages have made graphdiyne one of the hottest research frontiers of chemistry and materials science and produced a series of original and innovative research results in the fundamental and applied research of carbon materials. In recent years, considerable advances have been made toward the development of graphdiyne-based multiscale catalysts for nitrogen fixation and ammonia synthesis at room temperatures and ambient pressures. This review aims to provide a comprehensive update in regard to the synthesis of graphdiyne-based multiscale catalysts and their applications in the synthesis of ammonia. The unique features of graphdiyne are highlighted throughout the review. Finally, it concludes with the discussion of challenges and future perspectives relating to graphdiyne.

Ir0/graphdiyne atomic interface for selective epoxidation

The development of catalysts that can selectively and efficiently promote the alkene epoxidation at ambient temperatures and pressures is an important promising path to renewable synthesis of various chemical products. Here we report a new type of zerovalent atom catalysts comprised of zerovalent Ir atoms highly dispersed and anchored on graphdiyne (Ir⁰/GDY) wherein the Ir⁰ is stabilized by the incomplete charge transfer effect and the confined effect of GDY natural cavity. The Ir⁰/GDY can selectively and efficiently produce styrene oxides (SO) by electro-oxidizing styrene (ST) in aqueous solutions at ambient temperatures and pressures with high conversion efficiency of ∼100%, high SO selectivity of 85.5%, and high Faradaic efficiency (FE) of 55%. Experimental and density functional theory (DFT) calculation results show that the intrinsic activity and stability due to the incomplete charge transfer between Ir⁰ and GDY effectively promoted the electron exchange between the catalyst and reactant molecule, and realized the selective epoxidation of ST to SO. Studies of the reaction mechanism demonstrate that Ir⁰/GDY proceeds a distinctive pathway for highly selective and active alkene-to-epoxide conversion from the traditional processes. This work presents a new example of constructing zerovalent metal atoms within the GDY matrix toward selective electrocatalytic epoxidation.

Energy Storage Mechanism in Supercapacitors with Porous Graphdiynes: Effects of Pore Topology and Electrode Metallicity

Porous graphdiynes are a new class of porous 2D materials with tunable electronic structures and various pore structures. They have potential applications as well-defined nanostructured electrodes and can provide platforms for understanding energy storage mechanisms underlying supercapacitors. Herein, the effect of stacking structure and metallicity on energy storage with such electrodes is investigated. Simulations reveal that supercapacitors based on porous graphdiynes of AB stacking structure can achieve both higher double-layer capacitance and ionic conductivity than AA stacking. This phenomenon is ascribed to more intense image forces in AB stacking, leading to a breakdown of ionic ordering and the formation of effective "free ions". Macroscale analysis shows that doped porous graphdiynes can deliver outstanding gravimetric and volumetric energy and power densities due to their enhanced quantum capacitance. These findings pave the way for designing high-performance supercapacitors by regulating pore topology and metallicity of electrode materials.

Inhibition of transition-metal dissolution with an inert soluble product interface constructed by high-concentration electrolyte

The formation of a compact and stable cathode electrolyte interphase (CEI) film is a promising way to improve the high voltage resistance of lithium-ion batteries (LIBs). However, challenges arise due to the corrosion of hydrogen fluoride (HF) and the dissolution of transition metal ions (TMs) in harsh conditions. To address this issue, researchers have constructed an anion-derived CEI film enriched with LiF and LiPO₂F₂ soluble product on the surface of LiNi_0.5Mn_1.5O₄ (LNMO) cathode in highly concentrated electrolytes (HCEs). The strong binding of LiF and LiPO₂F₂ generated an inert LiPO₂F₂ soluble product interface, which inhibited HF corrosion and maintained the spinel structure of LNMO, contributing to a capacity retention of 92% after 200 cycles at 55°C in the resulting cell with a soluble LiPO₂F₂-containing CEI film. This new approach sheds light on improving the electrode/electrolyte interface for high-energy LIBs.

Two-Dimensional Carbon Graphdiyne: Advances in Fundamental and Application Research

Graphdiyne (GDY), a rising star of carbon allotropes, features a two-dimensional all-carbon network with the cohybridization of sp and sp² carbon atoms and represents a trend and research direction in the development of carbon materials. The sp/sp²-hybridized structure of GDY endows it with numerous advantages and advancements in controlled growth, assembly, and performance tuning, and many studies have shown that GDY has been a key material for innovation and development in the fields of catalysis, energy, photoelectric conversion, mode conversion and transformation of electronic devices, detectors, life sciences, etc. In the past ten years, the fundamental scientific issues related to GDY have been understood, showing differences from traditional carbon materials in controlled growth, chemical and physical properties and mechanisms, and attracting extensive attention from many scientists. GDY has gradually developed into one of the frontiers of chemistry and materials science, and has entered the rapid development period, producing large numbers of fundamental and applied research achievements in the fundamental and applied research of carbon materials. For the exploration of frontier scientific concepts and phenomena in carbon science research, there is great potential to promote progress in the fields of energy, catalysis, intelligent information, optoelectronics, and life sciences. In this review, the growth, self-assembly method, aggregation structure, chemical modification, and doping of GDY are shown, and the theoretical calculation and simulation and fundamental properties of GDY are also fully introduced. In particular, the applications of GDY and its formed aggregates in catalysis, energy storage, photoelectronic, biomedicine, environmental science, life science, detectors, and material separation are introduced.

Design, synthesis, and application of some two-dimensional materials

Two-dimensional (2D) materials are widely used as key components in the fields of energy conversion and storage, optoelectronics, catalysis, biomedicine, etc. To meet the practical needs, molecular structure design and aggregation process optimization have been systematically carried out. The intrinsic correlation between preparation methods and the characteristic properties is investigated. This review summarizes the recent research achievements of 2D materials in the aspect of molecular structure modification, aggregation regulation, characteristic properties, and device applications. The design strategies to fabricate functional 2D materials starting from precursor molecules are introduced in detail referring to organic synthetic chemistry and self-assembly technology. It provides important research ideas for the design and synthesis of related materials.

Scalable synthesis of soluble crystalline ionic-graphdiyne by controlled ion expansion

Graphdiyne (GDY) is a promising material possessing extensive electronic tunability, high π conjugacy, and ordered porosity at a molecular level for the sp/sp2-hybridized periodic structures. Despite these advantages, the preparation of soluble and crystalline graphdiyne is limited by the relatively compact stacking interactions, mostly existing in thick-layer and insoluble solids. Herein, we proposed a strategy of "framework charge-induced intercalation (FCII)" for the synthesis of a soluble (4.3 mg ml-1) and yet interlayer-expanded (∼0.6 Å) crystalline ionic graphdiyne, named as N+-GDY, through regulating the interlayer interactions. The skeleton of such a sample is positively charged, and then the negative ions migrate to the interlayer to expand the space, endowing the N+-GDY with solution processability. The crystal structure of N+-GDY is proved through analysis of HR-TEM images under different axes of observation and theoretical simulations. The resulting N+-GDY possesses high dispersity in organic solvents to produce a pure-solution phase which is conducive to the formation of oriented N+-GDY films, accompanied by exfoliation-nanosheet restacking. The film exhibits a conductivity of 0.014 S m-1, enabling its applications in electronic devices.