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.

We have critically examined the key role of acetylenic linkages (–CC–) in determining the opto-electronic responses of the dynamically stable tetragonal (T) ‘-ynes’ with the help of density functional theory.

In this paper a systematic study is carried out to demonstrate the structural stability and magnetic novelty of adsorbing transition metal (TM) dimers (A-B) on graphyne (GY) surface, GY@A-B. Our research points out that the dimers are strongly adsorbed onto GY due to their large natural pores and the electron affinity of the sp-hybridized carbon atoms. Electronic properties of these dimer-graphyne composite systems are of particular importance as they behave as degenerate semiconductors with partial occupation of states at E F. Furthermore, their remarkable spin polarization (>80%) at Fermi energy (E F) can be of paramount importance in spintronics applications. Most of the GY@A-B structures exhibit large magnetic anisotropies as well as magnetic moments along the out-of-plane direction with respect to the GY surface. Particularly, GY@Co–Ir, GY@Ir–Ir and GY@Ir–Os structures possess positive magnetic anisotropic energies (MAE) of 121 meV, 81 meV and 137 meV, respectively, which are comparable to other well-known TM dimer doped systems. The emergence of high MAE can be understood using the second-order perturbation theory on the basis of the strong spin–orbit coupling (SOC) between the two TMs and the degeneracy of their d-orbitals near E F. A close correspondence between the simulated and the analytical results has been established through our work. Further, a simple estimation shows that, GY@A-B structures have the potential to store data up to 64 PB m−2. These intriguing electronic characteristics along with magnetism suggest GY@A-B to be a promising material for future magnetic storage devices.

Global seafood sector is going through a massive shock during a global-scale disturbance named “COVID-19 Pandemic”. Restricting national and international trade and traffic was the most needed step to contain the spread of virus; meanwhile it has wreaked havoc on all import-export businesses. Seafood sector, is one of the major pillar behind agricultural export (fisheries sector contributing 1.07% to the Indian agricultural GDP) and blue revolution. But due to uncertainty of the lockdown periods, the Indian seafood sector has crashed, affecting livelihoods of all fishing and related communities, export and supply chain (both domestic and international), demand and consumption etc. The sudden crisis has exposed various shortcomings of the sector and expanded our vision to look ahead of temporary solutions and find long-term sustainability. Unavailability of real-time data from planned surveys are one of the major reasons behind this failure. This article aims to highlight the present scenario of the Indian seafood sector during the pandemic through assessing various news articles, national reports and publications. Further it suggests some recovery steps like building up alternative seafood networks, promoting domestic demand and markets, forming fishing community friendly schemes (medical and insurance), adopting new technologies to prevent and handle any future crisis.

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