Low dimensional materials have attracted great research interest from both theoretical and experimental point of views. These materials exhibit novel physical and chemical properties due to the confinement effect in low dimensions. The experimental observations of graphene open a new platform to study the physical properties of materials restricted to two dimensions. This featured article provides a review on the novel properties of quasi one‐dimensional (1D) material known as graphene nanoribbon. Graphene nanoribbons can be obtained by unzipping carbon nanotubes (CNT) or cutting the graphene sheet. Alternatively, it is also called the finite termination of graphene edges. It gives rise to different edge geometries, namely zigzag and armchair, among others. There are various physical and chemical techniques to realize these materials. Depending on the edge type termination, these are called the zigzag and armchair graphene nanoribbons (ZGNR and AGNR). These edges play an important role in controlling the properties of graphene nanoribbons. The present review article provides an overview of the electronic, transport, optical, and magnetic properties of graphene nanoribbons. However, there are different ways to tune these properties for device applications. Here, some of them, such as external perturbations and chemical modifications, are highlighted. Few applications of graphene nanoribbon have also been briefly discussed.

Orientation control of two-dimensional (2D) colloidal liquid crystals in both microscopic and macroscopic scales holds massive promise for improved multifield applications. In this respect, graphene oxide (GO) is used as a platform substance for 2D carbon-based lyotropic liquid crystal (LC) materials. Here, we design the directed alignment of aqueous GO-LC dispersion confined in a rectangular capillary tube. The isotropic GO dispersion is loaded into a horizontal capillary and subsequently concentrated to the LC phase by slow water evaporation at open ends of the tube. An obtained surprising result, GO layers organize normal to the inner surfaces of the capillary with a highly ordered orientation of the optic axis over tens of millimeters. Such transverse orientation of GO layers originates from the meniscus region and then moves toward the center, caused by the interfacial effect and the sequential isotropic-to-nematic transition. This aligned mesomorphic system is characterized via optical retardation, nematic order parameter, absorption, and modified Cauchy’s transmission equation about the dependency of both birefringence and wavelength with concentration. Finally, the aligned GO-LC layers are preserved in a polymer composite matrix by photopolymerizing the evaporation-aligned GO/acrylamide-LC dispersion confined in a capillary. This composite shows higher thermal stability than polyacrylamide until 500 °C of about 6.1%. Our experimental findings provide efficient advantages for controlling the orientation of GO-LC and 2D materials, beneficial for diverse optical applications due to their directional ordering.

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Air pollution is a severe concern globally as it disturbs the health conditions of living beings and the environment because of the discharge of acetone molecules. Metal oxide semiconductor (MOS) nanomaterials are crucial for developing efficient sensors because of their outstanding chemical and physical properties, empowering the inclusive developments in gas sensor productivity. This review presents the ZnO nanostructure state of the art and notable growth, and their structural, morphological, electronic, optical, and acetone-sensing properties. The key parameters, such as response, gas detection limit, sensitivity, reproducibility, response and recovery time, selectivity, and stability of the acetone sensor, have been discussed. Furthermore, gas-sensing mechanism models based on MOS for acetone sensing are reported and discussed. Finally, future possibilities and challenges for MOS (ZnO)-based gas sensors for acetone detection have also been explored.

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