This review deals with wide-ranging environmental studies of graphene-based materials on the adsorption of hazardous materials and photocatalytic degradation of pollutants for water remediation and the physisorption, chemisorption, reactive adsorption, and separation for gas storage. The environmental and biological toxicity of graphene, which is an important issue if graphene composites are to be applied in environmental remediation, is also addressed.

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Graphene sheets decorated with SnO(2) nanoparticles (RGO-SnO(2)) were prepared via a redox reaction between graphene oxide (GO) and SnCl(2). Graphene oxide (GO) was reduced to graphene (RGO) and Sn(2+) was oxidized to SnO(2) during the redox reaction, leading to a homogeneous distribution of SnO(2) nanoparticles on RGO sheets. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show uniform distribution of the nanoparticles on the RGO surface and high-resolution transmission electron microscopy (HRTEM) shows an average particle size of 3-5 nm. The RGO-SnO(2) composite showed an enhanced photocatalytic degradation activity for the organic dye methylene blue under sunlight compared to bare SnO(2) nanoparticles. This result leads us to believe that the RGO-SnO(2) composite could be used in catalytic photodegradation of other organic dyes.

Preventing the p-p restacking of graphene-based platelets is essential to advance their fundamental attributes in a wide range of scalable chemical processes. Using macroscopic hydrogels of waterintercalated metal-oxide/graphene platelets is a novel approach to produce microscopic hydrogels with extraordinary surface accessibility and electronic properties. Nanoparticle decoration and surface hydration prevent irreversible p-p stacking, paving the way for reversible self-assembly and aqueousphase exfoliation. The hydrophilic nanoparticle coating facilitates the colloidal stability of hybrid microgels in aqueous and organic media without the assistance of surfactants. This allows these materials to versatilely function as basic building blocks as well as applied nanomaterials in wetchemistry applications. The preservation of unique properties of SnO 2 -decorated graphene platelets leads to significantly enhanced adsorptive and photocatalytic activities. By exploiting the fluorescence quenching effect, a dye-hydrogel complex can be utilized as a supramolecular sensor for sensitive DNA detection. This study also initiates an innovative synthetic strategy to synthesize high-quality graphenebased nanomaterials.

In the present study, the suitability of zircon powder as a new distributive phase for electrodeposited Ni composite coating is explored.

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RNA controls many biological processes. The selective detection and imaging of RNA molecules can provide information about their location, kinetics, and functions at the cellular level. The imidazolium-based positively charged probes would play a significant role in the deep investigation of RNA biomolecules to check their therapeutic potential and aid in the future rational molecular and drug design.

Reduced graphene oxide/poly(pyrrol-co-thiophene) (RGO/COP), prepared by facile in-situ oxidative copolymerization, is reported as a new hybrid composite material with improved supercapacitance performance as compared to the respective homopolymers and their composites with RGO. The as-prepared hybrid materials were characterized with ultraviolet–visible (UV–Vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis. The electrochemical behavior and energy storage properties of the materials were tested by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrostatic impedance spectroscopy (EIS) techniques in 0.5 M H2SO4. The specific capacitance (Csp) for RGO/COP calculated from the CV curve was 467 F/g at a scan rate of 10 mV/s. While the Csp calculated from the GCD was 417 F/g at a current density of 0.81 A/g. The energy density calculated was 86.4 Wh/kg with a power density of 630 W/kg. The hybrid composite exhibits good cyclic stability with 65% capacitance retention after 1000 cycles at a scan rate of 100 mV/s. The present work brings a significance development of RGO/COP composites to the electrode materials for pseudocapacitive application.