: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Flat carbon (sp(2) and sp) networks endow the graphdiyne and graphyne families with high degrees of π-conjunction, uniformly distributed pores, and tunable electronic properties; therefore, these materials are attracting much attention from structural, theoretical, and synthetic scientists wishing to take advantage of their promising electronic, optical, and mechanical properties. In this Review, we summarize a state-of-the-art research into graphdiynes and graphynes, with a focus on the latest theoretical and experimental results. In addition to the many theoretical predictions of the potential properties of graphdiynes and graphynes, we also discuss experimental attempts to synthesize and apply graphdiynes in the areas of electronics, photovoltaics, and catalysis.

Graphdiyne and graphyne: from theoretical predictions to practical construction

Graphynes (GYs) are carbon allotropes with single-atom thickness that feature layered 2D structure assembled by carbon atoms with sp- and sp2- hybridization form. Various functional theories have predicted GYs to have natural band gap with Dirac cones structure, presumably originating from inhomogeneous π-bonding between those carbon atoms with different hybridization and overlap of the carbon 2pz orbitals. Among all the GYs, graphdiyne (GDY) was the first reported to be prepared practically and, hence, attracted the attention of many researchers toward this new planar, layered material, as well as other GYs. Several approaches have been reported to be able to modify the band gap of GDY, containing invoking strain, boron/nitrogen doping, nanoribbon architectures, hydrogenation, and so on. GDY has been well-prepared in many different morphologies, like nanowires, nanotube arrays, nanowalls, nanosheets, ordered stripe arrays, and 3D framwork. The fascinating structure and electronic properties of GDY make i...

Progress in Research into 2D Graphdiyne-Based Materials

In this review, we discuss the most recent progress on graphene-related nanomaterials, including doped graphene and derived graphene nanoribbons, graphene oxide, graphane, fluorographene, graphyne, graphdiyne, and porous graphene, from both experimental and theoretical perspectives, and emphasize tuning their stability, electronic and magnetic properties by chemical functionalization.

Graphene-related nanomaterials: tuning properties by functionalization

Graphdiyne (GDY), a new two-dimensional (2D) carbon allotrope, has been receiving increased attention. Its unique sp-sp2 carbon atoms, uniform pores, and highly π-conjugated structure provide promising potential in practical applications, such as gas separation, catalysis, water remediation, humidity sensor, and energy-related fields. In the recent years, considerable efforts have been expended toward the development of well-defined GDY. However, GDY materials still face numerous challenges, including the need for a more thorough understanding of the growth mechanism, strategies for synthesizing one- or few-layer single-crystalline GDY films, characterization of basic physicochemical properties, and achievement of promising applications. This review aims at providing a comprehensive update on the synthesis of GDY and GDY-based materials, as well as their properties, including structural, electronic, mechanical, and spectral properties, and their applications in nanotechnology.

Graphdiyne: synthesis, properties, and applications

Graphdiyne nanotube (GDNT) arrays were prepared through an anodic aluminum oxide template catalyzed by Cu foil. The as-grown nanotubes have a smooth surface with a wall thickness of about 40 nm; after annealing, the GDNTs are about 15 nm. The morphology-dependent field emission properties of graphdiyne arrays were measured and display high performance field emission properties. The turn-on field and threshold field of GDNTs annealed decreased to 4.20 and 8.83 V/μm, respectively.

Construction of Tubular Molecule Aggregations of Graphdiyne for Highly Efficient Field Emission

We described a new structure photodetector, which is constructed by p–n heterojunction nanowire arrays of PANI (polyaniline)/CdS. The nanowire arrays exhibit excellent rectifying features and a diode nature and show a sensitive spectral response to blue light under 420 nm. The rectification ratio plots of different illumination intensities show straight line behavior, implying that the quantitative detection of illumination intensity can be achieved. The p–n heterojunction nanowire array is a great candidate for applications in high-sensitivity and high-speed blue light photodetectors.

Constructing a blue light photodetector on inorganic/organic p-n heterojunction nanowire arrays

The end-to-end P–N heterojunction nanowire arrays combined organic (poly[1,4-bis(pyrrol-2-yl)benzene], BPB) and inorganic (CdS) molecules have been successfully designed and fabricated. The electrical properties of P–N heterojunctions of organic–inorganic nanowire arrays were investigated. The diode nature and rectifying feature of P–N heterojunction nanowire arrays were observed. The rectification ratio of the diode increased from 29.9 to 129.7 as the illumination intensity increased. The material exhibits a new property, which is an improvement in the integration of the physical and chemical properties of the two independent components.

Synthesis and characterization of axial heterojunction inorganic–organic semiconductor nanowire arrays

In this report, we present a novel platform to study the formation of two π-conjugated conducting copolymer nanowire arrays based on 3,4-ethylenedioxythiophene (EDOT) and thieno[3,4-b]thiophene (T34bT). The resulting nanostructures have a highly uniform wire array architecture with tunable diameters. This combination of nanoporous templates and in situ electropolymerization strategy offers a versatile route to prepare copolymers, forming uniform one-dimensional nanomaterials potentially useful in electronic conductor and field emission applications.

Growing uniform copolymer nanowire arrays for high stability and efficient field emission

Controlling the fabrication of the nanowire-nanotube junctions of a dichloro-bridged dimeric iridium complex of 2-phenylpyridine (IPPC) has been achieved by a facile template method. IPPC nanowire-nanotube junctions were prepared at 15 °C, and IPPC nanotubes could be formed by increasing the temperature. It is interesting that IPPC solid nanowires were produced when the temperature decreased to 0 °C. The results show that temperature is a key factor for controlling the process of growth. The emission of the IPPC nanostructures showed a blue shift and a stronger intensity in comparison to IPPC bulk materials.

Haowei Lin

Papers

Construction of Tubular Molecule Aggregations of Graphdiyne for Highly Efficient Field Emission

Constructing a blue light photodetector on inorganic/organic p-n heterojunction nanowire arrays

Synthesis and characterization of axial heterojunction inorganic–organic semiconductor nanowire arrays

Growing uniform copolymer nanowire arrays for high stability and efficient field emission

Controlling the growth of low dimension nanostructures of an iridium complex