Structural and electronic properties of α-, β-, γ-, and 6,6,18-graphdiyne sheets and nanotubes

Graphdiyne-loaded polycaprolactone nanofiber scaffold for peripheral nerve regeneration

Graphdiyne (GDY) is a kind of nanomaterial from the graphene carbon family with excellent physical and chemical properties. Despite some applications in medical engineering, GDY has not been used as an electroactive scaffold for tissue regeneration because of its unclear in vitro and in vivo biosafety profiles. Here, a conductive GDY nanomaterial-loaded polycaprolactone (PCL) scaffold was prepared by electrospinning technique. For the first time, the biocompatibility of GDY-based scaffold was assessed at the cellular and animal levels in a peripheral nerve injury (PNI) model. The findings indicated that the conductive three-dimensional (3D) GDY/PCL nerve guide conduits (NGCs) could significantly improve the proliferation, adhesion and glial expression of Schwann cells (SCs). The conduits were implanted into a rat 10-mm sciatic nerve defect model for 3 months in vivo. The toxicity of scaffolds to the organs was negligible, while the GDY/PCL NGCs significantly promoted myelination and axonal growth by upregulating the expression levels of SC marker (S100 β protein), Myelin basic protein (MBP), and axon regeneration marker (β3-tubulin protein (Tuj1) and neurofilament protein 200 (NF200)). In addition, upregulation of vascular factor expression in GDY/PCL NGC group suggested the potential role in angiogenesis to improve nerve repair by GDY nanomaterials. Our findings provide new perspectives on biocompatibility and effectiveness of GDY nanomaterial scaffold in peripheral nerve regeneration for preclinical application.

Recent progress in neuromorphic and memory devices based on graphdiyne

Graphdiyne (GDY) is an emerging two-dimensional carbon allotrope featuring a direct bandgap and fascinating physical and chemical properties, and it has demonstrated its promising potential in applications of catalysis, energy conversion and storage, electrical/optoelectronic devices, etc. In particular, the recent breakthrough in the synthesis of large-area, high-quality and ultrathin GDY films provides a feasible approach to developing high-performance electrical devices based on GDY. Recently, various GDY-based electrical and optoelectronic devices including multibit optoelectronic memories, ultrafast nonvolatile memories, artificial synapses and memristors have been proposed, in which GDY plays a crucial role. It is essential to summarize the recent breakthrough of GDY in device applications as a guidance, especially considering that the existing GDY-related reviews mainly focus on the applications in catalysis and energy-related fields. Herein, we review GDY-based novel memory and neuromorphic devices and their applications in neuromorphic computing and artificial visual systems. This review will provide an insight into the design and preparation of GDY-based devices and broaden the application fields of GDY.

Graphdiyne-Related Materials in Biomedical Applications and Their Potential in Peripheral Nerve Tissue Engineering

Graphdiyne (GDY) is a new member of the family of carbon-based nanomaterials with hybridized carbon atoms of sp and sp², including α, β, γ, and (6,6,12)-GDY, which differ in their percentage of acetylene bonds. The unique structure of GDY provides many attractive features, such as uniformly distributed pores, highly π-conjugated structure, high thermal stability, low toxicity, biodegradability, large specific surface area, tunable electrical conductivity, and remarkable thermal conductivity. Therefore, GDY is widely used in energy storage, catalysis, and energy fields, in addition to biomedical fields, such as biosensing, cancer therapy, drug delivery, radiation protection, and tissue engineering. In this review, we first discuss the synthesis of GDY with different shapes, including nanotubes, nanowires, nanowalls, and nanosheets. Second, we present the research progress in the biomedical field in recent years, along with the biodegradability and biocompatibility of GDY based on the existing literature. Subsequently, we present recent research results on the use of nanomaterials in peripheral nerve regeneration (PNR). Based on the wide application of nanomaterials in PNR and the remarkable properties of GDY, we predict the prospects and current challenges of GDY-based materials for PNR.

Emerging properties of carbon based 2D material beyond graphene

Graphene turns out to be the pioneering material for setting up boulevard to a new zoo of recently proposed carbon based novel two dimensional (2D) analogues. It is evident that their electronic, optical and other related properties are utterly different from that of graphene because of the distinct intriguing morphology. For instance, the revolutionary emergence of Dirac cones in graphene is particularly hard to find in most of the other 2D materials. As a consequence the crystal symmetries indeed act as a major role for predicting electronic band structure. Since tight binding calculations have become an indispensable tool in electronic band structure calculation, we indicate the implication of such method in graphene's allotropes beyond hexagonal symmetry. It is to be noted that some of these graphene allotropes successfully overcome the inherent drawback of the zero band gap nature of graphene. As a result, these 2D nanomaterials exhibit great potential in a broad spectrum of applications, viz nanoelectronics, nanooptics, gas sensors, gas storages, catalysis, and other specific applications. The miniaturization of high performance graphene allotrope based gas sensors to microscopic or even nanosized range has also been critically discussed. In addition, various optical properties like the dielectric functions, optical conductivity, electron energy loss spectra reveal that these systems can be used in opto-electronic devices. Nonetheless, the honeycomb lattice of graphene is not superconducting. However, it is proposed that the tetragonal form of graphene can be intruded to form new hybrid 2D materials to achieve novel superconducting device at attainable conditions. These dynamic experimental prospects demand further functionalization of these systems to enhance the efficiency and the field of multifunctionality. This topical review aims to highlight the latest advances in carbon based 2D materials beyond graphene from the basic theoretical as well as future application perspectives.