Engineering Graphdiyne for Solar Photocatalysis

Graphdiyne (GDY) with a direct band gap, excellent carrier mobility and uniform pores, is regarded as a promising photocatalytic material for solar energy conversion, while the research on GDY in photocatalysis is a less developed field. Herein, the distinctive structure, adjustable band gap, and electronic properties of GDY for photocatalysis is firstly summarized. The construction and progress of GDY-based photocatalysts for solar energy conversion, including H₂ evolution reaction (HER), CO₂ reduction reaction (CO₂RR) and N₂ reduction reaction (NRR) are then elaborated. At last, the challenges and perspectives in developing GDY-based photocatalysts for solar fuel production are discussed. It is anticipated that a timely Minireview will be helpful for rapid progress of GDY in solar energy conversion.     

二维碳石墨炔的结构及其在能源领域的应用

从二维碳材料石墨炔(GDY)的分子和电子结构出发,重点论述石墨炔在能源存储和转换两个领域的应用,包括最新的理论和实验进展。石墨炔独特的三维孔隙结构,使得石墨炔在锂存储和氢气存储应用中具备天然的优势,既可以用作锂离子相关的储能器件,包括锂离子电池、锂离子电容器等;也可作为储氢材料,用于燃料电池等。通过掺杂的方法,还能进一步提高石墨炔储锂和储氢的性能。由于sp炔键和sp²苯环的存在,使石墨炔具有多重共轭的电子结构,在具备狄拉克锥的同时,其带隙也可通过多种途径调控,使得石墨炔不仅可以作为非金属高活性催化剂替代贵金属在光催化等方面应用,还可以在太阳能电池的空穴传输层和电子传输层方面获得应用,展现了石墨炔在能源方面独特的应用价值。我们将从理论预测和实验研究两方面介绍该领域目前的研究现状和发展趋势。     

Heteroatom Doped Graphdiyne and Analogues:Synthesis,Structures and Applications

As a new carbon allotrope,graphdiyne(GDY)has shown intensive practical application prospects in the energy field,catalysis,gas separation,etc.,due to its unique 2D π-conjugated structure,rich sp-hybridized carbon atoms and semiconductor characteristics.Considerable efforts have been made to the development of well-defined GDY materials in recent years.The doping heteroatoms can further tune the structures,semiconductor properties of GDY,and expand the promising applications.This review summarized a comprehensive development of heteroatom doped GDYs,including their synthesis,structures,properties,applications in nanotechnology,as well as the forecast in the future.     

Halogen-Driven Bandgap Opening in Graphdiyne for Overall Photocatalytic Water Splitting

In this work, we studied the electronic band structure of the halogen (F, Cl, and Br) functionalized graphdiynes (GDYs) by using hybrid density functional theory. The results revealed that the bandgap energies of modified GDYs increase as the number of halogen atoms increases. It is also found that the position of the valence band maximum (VBM) is influenced by the electronegativity of halogen atoms. The higher the electronegativity, the deeper the VBM of the GDYs modified by the same number of halogen atoms. Importantly, our results revealed that the bandgap of GDY could be effectively tuned by mixing types of halogen atoms. The new generated conduction band and valence band edges are properly aligned with the oxidation and reduction potentials of water. Further thermodynamic analysis confirms that some models with mixing types of halogen atoms exhibit higher performance of overall photocatalytic water splitting than non-mixing models. This work provides useful insights for designing efficient photocatalysts that can be used for overall water splitting.     

A Photoelectrochemical Immunosensor for Prostate Specific Antigen Detection Based on Graphdiyne Oxide Conjugated with Horseradish Peroxidase

Graphdiyne (GDY) was a novel flat material with sp and sp² hybridized carbon atoms. It exhibited good biocompatibility. The application of GDY in PEC immunosensor was very limited. Thus, a novel photoelectrochemical sensor for the sensitive detection of prostate specific antigen (PSA) was proposed by using GDY oxide (GDYO) conjugated with horseradish peroxidase (HRP) and secondary antibody for photocurrent signal inhibition. GDYO was prepared by oxidation of honeycomb-like nanotubes composed of numerous GDY nanosheets. It showed high loading capacity for HRP and the catalytic activity of HRP could be remained. With reduced graphene oxide-CdS (rGO-CdS) as photoelectrochemical sensing platform, a sandwich-type photoelectrochemical (PEC) immunosensor was thus fabricated. The immunosensor presented a wide linear concentration range of 10 fg mL⁻¹–20.0 ng mL⁻¹ with a detection limit (LOD) of 3.5 fg mL⁻¹. Moreover, the PEC immunosensor displayed ideal reproducibility, stability, and selectivity, which was a promising platform for the detection of other important tumor targets.     

石墨炔结构表征及在光电催化反应中的应用

石墨炔是一种新型碳材料,自2010年实验室成功制备后受到广泛关注。石墨炔是一种由sp和sp²杂化碳组成的高度共轭结构。随着石墨炔合成化学的发展,多种不同构型的石墨炔被制备和表征。石墨炔特殊的电子和孔结构,使其在催化领域中具有广泛的应用。本文总结了近年来石墨炔材料在表征方法和光电催化反应方面的研究进展,并探讨了石墨炔未来发展的机遇和挑战。     

石墨炔孔结构:设计、合成和应用

石墨炔作为一种新兴碳材料, 由于具有特殊的电子特性、 丰富的纳米级孔隙以及能在相对低温下合成的特点, 在催化、 能源及生物等领域受到广泛关注. 石墨炔自下而上的合成特点使其在结构上具有可设计性, 而其显著特征在于具有拓扑有序的规则孔道结构. 在过去的10年间, 研究人员在石墨炔孔结构设计方面进行了大量的实验和理论研究. 孔结构设计所带来的独特性能为其提供了良好的应用前景. 本文从石墨炔的合成特点出发, 总结了单体、 催化剂、 模板及溶液4个因素对石墨炔结构的影响, 并从孔结构出发讨论了其应用. 为研究者以应用为导向, 设计合成具有特殊孔结构的石墨炔提供了思路. 最后还探讨了孔结构设计给石墨炔带来的机遇与挑战, 并对三维多孔结构石墨炔的设计进行了展望.     

无机氧化剂在光催化氧化技术中的应用

光催化氧化作为高级氧化技术的一种在环境保护领域具有重要的应用前景。就目前而言,量子效率低、反应速度慢等缺点制约了光催化氧化的应用。投加无机氧化剂能够通过抑制空穴电子对的复合及产生其它氧化物种等方式强化光催化、提高光催化效率,推进光催化在实际中应用的进程。本文较详细地阐述了不同无机氧化剂强化光催化的机理、研究进展,并对无机氧化剂在光催化氧化中的应用前景进行展望。     

石墨炔的化学修饰及功能化

石墨炔特殊的电子结构和孔洞结构使其在信息技术、电子、能源、催化以及光电等领域具有潜在、重要的应用前景。近几年石墨炔的基础和应用研究已取得了重要成果,并迅速成为了碳材料研究中的新领域。石墨炔中炔键单元的高活性为其化学修饰与掺杂提供了良好的平台。在这篇综述中,我们将重点介绍石墨炔的非金属杂原子掺杂、金属原子修饰以及表面改性,并深入探讨掺杂与衍生化对石墨炔材料的电子性质的影响及其对光电化学催化性能的协同增强。     

石墨炔衍生物的合成与应用

石墨炔是由sp和sp²两种杂化碳构成的新型二维碳同素异形体。基于石墨炔化学合成规律和独特优势,利用其他芳炔前体替代六乙炔基苯,可以获得结构特异、尺寸可控的石墨炔基衍生物,而局域碳骨架的改变可以实现石墨炔衍生物性能调控,包括电导率、带隙、迁移率、空腔尺寸和电荷分离等。这类具有优良半导体性能的石墨炔基衍生物可以广泛应用于电化学储能、电催化、光电转换器件、非线性光学等诸多领域。本文主要综述了近年来石墨炔衍生物的优化设计、结构表征和光电性能,并对其代表性应用进行了总结和展望。     

Template Synthesis and Characterization of Cu2O/TiO2 Coaxial Nanocable for Photocatalysis

Coaxial nanocable consisted of p-type Cu₂O nanowires and n-type TiO₂ nanotubes arrays was prepared in the porous anodic aluminum oxide(AAO) template via the sol-gel method and subsequent electrodeposition method. X-ray diffraction analysis identified an anatase structure of the TiO₂ nanotubes and cubic structure of the Cu₂O nanowires. The obtained samples were also characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM) and energy dispersive X-ray spectroscopy(EDS). The diffrence of open circuit potential of the coaxial nanocable electrode was larger than that of the TiO₂ nanotubes electrode under ultraviolet illumination, which means doping with Cu₂O could improve the photovoltage effectively. Meanwhile, nanocable arrays exhibited a high activity for photodegrading Rhodamine B under Xe lamp irradiation and the photocatalysis degradation efficiency was up to 98.69% after degradation for 7 h. The enhanced photocatalytic activity could be attributed to the high migration efficiency of photoinduced electrons, which may suppress the charge recombination effectively.     

Post-modified Strategies of Graphdiyne for Electrochemical Applications

The new carbon material graphdiyne (GDY) has been verified to have a great application prospect in electrochemical field. In order to study its properties and expand its scope of application, various experiments including structural control tests are imposed on GDY. Among them, as one of the most commonly used methods to modify the structure, heteroatom doping is favored for its advantages in synthesis methods and the control of mechanical, electrical and even magnetic properties of carbon materials. According to the published studies, the top-down methods of doping heteroatoms for GDY only need cheap raw materials, simple synthetic route and strong controllability, which is conducive to rapid performance breakthroughs in electrochemical applications. This review selects the typical cases in the development of that post-modification method from the application of GDY in the electrochemical field. Here, based on the existed reports, the commonly used non-metal elements (such as nitrogen, sulfur) and metal elements (such as iron) have been introduced to post-modify GDY. Then, a detailed analysis is made for corresponding electrochemical applications, such as energy storage and electrocatalysis. Finally, the challenges and prospects of post-modified GDY in synthesis and electrochemical applications are proposed. This review provides us a useful guidance for the development of high-quality GDY suitable for electrochemical applications.     

Nitrogen-rich Graphdiyne Film for Efficiently Suppressing the Methanol Crossover in Direct Methanol Fuel Cells

The inhibition of the methanol crossover is one of the intractable challenges in the direct methanol fuel cell.The graphdiyne(GDY)with atomic-level pores shows great potential in realizing the zero-permeation of methanol molecules.In this paper,an ultrathin layer of nitrogen-rich GDY film with a high nitrogen content is largely prepared and readily used for retarding the methanol permeation in the state-of-the-art commercial Nafion membrane.The high N-content in this porous GDY nanofilm remarkably increases the selective suppression in methanol transfer,and single-layer GDY film can efficiently prevent 43％methanol crossover and the value of the double-layer GDY film can be high up to 69％.The power performance and the long-term stability of the cell are obviously improved due to the reduced methanol crossover.     

石墨炔零价金属原子催化剂的合成及应用

原子催化剂是零价金属原子锚定于载体上的一种新型催化剂, 具有原子利用率高、 选择性高以及反应活性和稳定性高等优点, 一直是催化领域的研究前沿, 在催化和能量转换领域具有广阔的发展前景. 石墨炔与金属原子之间独特的不完全电荷转移性质实现了零价过渡金属原子的稳定锚定, 解决了传统单原子催化剂易迁移和聚集的问题, 被认为是新一代催化剂. 本综述从石墨炔原子催化剂的结构性质、 表征以及应用等方面出发, 综合评述了相关领域的最新研究成果, 介绍了石墨炔原子催化剂在电催化固氮制氨、 产氢、 全水解和CO₂固定等方面的应用和发展前景, 为实现新概念高性能催化材料的设计合成提供了研究思路.     

Single-Atom Protecting Group for on-Surface Synthesis of Graphdiyne Nanowires

On-surface synthesis of semiconducting graphdiyne nanowires usually suffer severe side reactions owing to the high reactivity of the butadiynylene units at noble metal surfaces, limiting the production of isolated nanowires. In this work, we report the high-yield synthesis of branchless graphdiyne nanowires [-C≡C-Ph₂-C≡C-]_n via on-surface Ullmann coupling of 1,4-bis(4-bromophenyl)-1,3-butadiyne molecules with chemical vapor deposition method. Non-contact atomic force microscopy with single-bond resolution reveals that single gold adatoms act as effective protecting groups for butadiynylene units by forming Au-π ligand bonds, preventing unwanted branched coupling reactions and enabling the synthesis of ultralong isolated graphdiyne nanowires. This study will stimulate further investigation on the role of various surface adatoms in protecting on-surface reactions.     

Graphdiyne:A Versatile Material in Electrochemical Energy Conversion and Storage

Graphdiyne(GDY),which is composed of sp2-/sp-hybridized carbon atoms,has attracted increasing attention.In the structure of GDY,the existence of large triangular-like pores,well dispersed electron-rich cavities as well as a large π-conjugated structure endows GDY with a natural bandgap,fast electron/ion transport,and tunable electronic properties.These unique features make GDY competitive in areas of gas separation and capture,electronics,detectors,catalysts,biomedicine and therapy,and energy-related fields.Benefiting from the facile synthesis method,various GDY structures and GDY-based composites have been successfully prepared and show great potential in the practical application of energy storage and catalysis areas.Here,this review aims at providing a timely and comprehensive update on the preparation and application of GDY materials.The current development of GDY materials in various electrochemical fields especially in energy conversion,energy storage,and catalysis is mainly summarized.Moreover,the potential development prospects are also discussed.     

Giant Water Uptake Enabled Ultrahigh Proton Conductivity of Graphdiyne Oxide

Proton conductors have attracted great attention in various fields, especially in energy production. Here, we find that graphdiyne oxide (GDYO), derived from graphdiyne (GDY), features the highest proton conductivity of 0.54 S cm⁻¹ (100 % RH, 348 K) among the oxidized carbon allotropes reported so far. The sp- and sp²-co-hybridized carbon skeleton of GDY enables GDYO with the giant water uptake, which is 2.4 times larger than that of graphene oxide (GO), resulting in ultrahigh proton conductivity by increasing the proton concentration and proton conduction pathways. This ultrahigh proton conductivity of GDYO is further proved in a methanol fuel cell by using GDYO membrane as proton exchange membrane. The GDYO membrane enables the cell with higher open circuit voltage, larger power density and lower methanol permeability, compared with commercial Nafion 117. Moreover, the GDYO membrane bears high ion exchange capacity, good acidic stability and low swelling ratio.     

石墨炔电化学电池界面构筑

石墨炔是新兴的碳同素异形体, 其独特的结构和性质引起了不同领域科学家的广泛关注. 研究表明, 石墨炔在能源、 催化、 光学、 磁学、 信息科学和生命科学等领域发展潜力巨大. 近年来, 石墨炔在电化学能源领域的基础和应用研究展现了石墨炔作为电化学能源材料所具有的独特优势, 为解决电化学能源器件所面临的科学瓶颈提供了新理念、 新方法和新概念. 本文综合评述了近3年来石墨炔在电化学电池界面应用方面的研究进展, 主要涉及二维石墨炔的制备和结构优势, 及其为多种电化学电池电极界面构筑、 界面选择性传输及电极界面稳定性等带来的新启发.     

含异原子石墨炔基电极材料的研究进展

碳材料具有价格低廉、 易制备、 环境友好、 导电性高、 比表面积大以及适合离子存储和迁移等优点, 已成为目前应用于电化学储能器件电极的重要材料之一. 石墨炔(GDY)是一种新型的二维碳同素异形体, 由sp²碳杂化形式的苯环和sp碳杂化形式的炔键构成. 这种独特的化学结构一方面保持了碳材料良好的导电特性, 另一方面形成了新颖的离子传输通道, 为碳材料带来了不同的离子传输和存储特性. 与此同时, 由于石墨炔的空间结构可调性, 可以通过引入异原子微调石墨炔电子结构, 拓展石墨炔在电极材料领域的应用. 本文重点对近几年异原子杂化石墨炔基电极材料在锂离子电池、 钠离子电池、 金属硫电池、 电容器、 金属空气电池和电极保护等储能领域的研究工作进行总结, 并对未来石墨炔类材料在储能领域的发展进行了展望.