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Graphene, a single sp² bonded carbon, is now a burgeoning interest with various fascinating properties in a large number of biomedical applications. Consequently, the impact of graphene-based functional nanohybrid and its potential risk to human health have raised considerable public concerns. In this present study, we have synthesized cerium oxide (CeO₂) anchored reduced graphene oxide (RGO) nanohybrid and a detailed study on its nanotoxicity profile has also been scrutinized. To confirm the efficient synthesis of nano-CeO₂/RGO nanohybrid, the systematic characterization has been carried out using FTIR, Raman and UV-Vis spectroscopic analysis. The successful imprint of CeO₂ nanoparticles (NPs) on RGO nanosheet was also evident from the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs. A dose-dependent in vitro nanotoxicity of the nanohybrid has been assessed by using monocyte macrophage cells-Raw264.7 and colon cancer cells-HCT116 as compared with RGO and CeO₂. The results conferred that as compared with single nanostructures (RGO or CeO₂), nanohybrid showed excellent biocompatibility and no such prominence morphological alteration of the cell structure. Moreover, after exposure of different nanomaterials to HCT116 cells, the possible cellular interaction was investigated through reactive oxygen species (ROS) measurements using flow cytometry analysis dicholoro-dihydro-fluorescen dia-acetate (DCF) assay. These results conveyed that nanohybrid adapts an oxidative stress mechanism upon cellular interaction where it utilizes the scavenging property of CeO₂, which induces the cell proliferation. Overall, the nano-CeO₂/RGO nanohybrid exhibits a prolonged biocompatibility and cell viability, which is highly desired for biomedical applications.

A one-step high-temperature solvothermal approach to the synthesis of monolayer or bilayer MoS₂ anchored onto reduced graphene oxide (RGO) sheet (denoted as MoS₂/RGO) is described. It was found that single-layered or double-layered MoS₂ were synthesized directly without an extra exfoliation step and well dispersed on the surface of crumpled RGO sheets with random orientation. The prepared MoS₂/RGO composites delivered a high reversible capacity of 900mAhg${}^{-1}$ after 200 cycles at a current density of 200mAg${}^{-1}$ as well as good rate capability as anode active material for lithium ion batteries. This one-step high-temperature hydrothermal strategy provides a simple, cost-effective and eco-friendly way to the fabrication of exfoliated MoS₂ layers deposited onto RGO sheets.

A novel ternary Cu₂O/BiVO₄/RGO photocatalyst is successfully constructed by hydrothermal and evaporation-induced method, and it exhibits superior photocatalytic performance for degradation tetracycline (TC). Meanwhile, the visible light absorption range of composite photocatalyst is effectively broadened by the formation of heterojunction with narrow band gap semiconductor Cu₂O. And the separation efficiency of the photogenerated electron–hole pairs is significantly enhanced by the synergistic effect of Cu₂O and RGO. More importantly, the adsorption of TC by ternary Cu₂O/BiVO₄/RGO possesses high adsorption capacity, which is 23.73 times higher than that of pure BiVO₄. Additionally, the possible reaction mechanism is clearly revealed by radical trapping experiment, electron spin-resonance (ESR) spectroscopy. This work provides a new insight to design a photocatalyst with excellent adsorption to remove organic contaminants in water.

In our study, a simple strategy to fabricate an efficient cobalt-based nanocatalyst is reported. The as-fabricated cobalt nanoparticles (Co NPs) that supported on reduced amine-functionalized graphene oxide (Co@RGO-NH${}_2)$ have been fabricated through reduction of Co${}^{2+}$ and GO-NH₂ by sodium borohydride under mild conditions. The morphology, elemental analysis, chemical composition, surface area and magnetic property of the as-fabricated Co@RGO-NH₂ nanocatalyst have been investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) and vibrating sample magnetometer (VSM), respectively. Characterization showed that Co@RGO-NH₂ nanocatalyst possesses a high surface area (232.05 m²/g) and good magnetic property. Obviously, the as-fabricated Co@RGO-NH₂ nanocatalyst exhibited a fascinating catalytic activity towards the catalytic reduction of different substituted nitro anilines pollutants ($o$-nitroaniline, $m$-nitroaniline and $p$-nitroaniline), as well as, the degradation of cationic methylene blue and anionic Congo red dyes. Furthermore, the reused Co@RGO-NH₂ nanocatalyst has shown high catalytic activity for all the catalytic reactions even after the fifth cycle, asserting the high stability of the as-fabricated heterogeneous catalyst.