Integration Of Reduced Graphene Oxide Research Articles

One-pot facile synthesis of hexagonal Bi2Te3 nanosheets and its novel nanocomposites: Characterization, anticancer, antibacterial, and antioxidant activities

Bismuth Telluride (Bi2Te3) layered structure results in extraordinary features in diagnostic and therapeutic applications. However, Bi2Te3 synthesis with reliable stability and biocompatibility in biological systems was the major challenge that limited its biological application. Herein, reduced graphene oxide (RGO) or graphitic carbon nitride (CN) nanosheets were incorporated into Bi2Te3 matrix to improve exfoliation. Bi2Te3 nanoparticles (NPs) and its novel nanocomposites (NCs): CN@Bi2Te3 and CN-RGO@Bi2Te3 were solvothermally synthesized, physiochemically characterized and assessed for their anticancer, antioxidant, and antibacterial activities. X-ray diffraction depicted Bi2Te3 rhombohedral lattice structure. Fourier-transform infrared and Raman spectra confirmed NC formation. Scanning and transmission electron microscopy revealed 13 nm thickness and 400–600 nm diameter of hexagonal, binary, and ternary nanosheets of Bi2Te3-NPs/NCs. Energy dispersive X-ray Spectroscopy revealed the presence of Bi, Te, and carbon atoms in the tested NPs with negatively charged surfaces as depicted by zeta sizer. CN-RGO@Bi2Te3-NC displayed the smallest nanodiameter (359.7 nm) with the highest Brunauer–Emmett–Teller surface area and antiproliferative activity against MCF-7, HepG2 and Caco-2. Bi2Te3-NPs had the greatest scavenging activity (96.13 ± 0.4%) compared to the NCs. The NPs inhibitory activity was greater against Gram-negative bacteria than that of Gram-positive bacteria. Integration of RGO and CN with Bi2Te3-NPs enhanced their physicochemical properties and therapeutic activities giving rise to their promising capacity for future biomedical applications.

Growth of ZnFe2O4 nanosheets on reduced graphene oxide with enhanced ethanol sensing properties

The design and synthesis of materials with unique hierarchical structure has important scientific and practical significance in improving their sensing properties. Herein, ZnFe2O4 nanoparticles assembled nanosheets (ZnFe2O4NSs) grown on reduced graphene oxide (RGO) was creatively constructed via a simple and fast microwave-assisted solvothermal method. RGO played the role as ground for the growth of ZnFe2O4NSs, and the growing process was investigated by a series of irradiation time dependent experiments. Finally, the gas sensing properties for the as-prepared ZnFe2O4NSs/RGO composites were evaluated. The integration of RGO was found to increase the selectivity of ZnFe2O4 to ethanol. It was found that the ZnFe2O4NSs/RGO composite with an irradiation time of 4 h (ZnFe2O4NSs/RGO 4 h) based sensor showed better ethanol sensing performance than that of sensors based on ZnFe2O4NSs assembled sphere without RGO, ZnFe2O4 nanoparticles and ZnFe2O4NSs/RGO composites with other irradiation time, respectively. ZnFe2O4NSs/RGO 4 h based sensors showed good stability and satisfied response to ethanol ranging from 0.1 ppm to 100 ppm at 210℃. The high response was attributed to its unique architecture, the integration of RGO and the formation of heterojunction between RGO and ZnFe2O4.

Preparation of Reduced Graphene Oxide (RGO) Modified Titanium Dioxide Nanotube (TNTs) as Visible Light Effective Catalyst for the Conversion of CO2 to CH4

In this study, a modified visible light active photocatalyst has been prepared where titanium dioxide nanotube (TNTs) was coupled with reduced graphene oxide (RGO) through a facile synthesis process. The photoactivity of the RGO-TNTs has been evaluated by converting CO2 to CH4 under visible light irradiation. In order to justify the photo-effectivity of the catalysts, physical and optical characterization were performed through FESEM, EDX, UV-Vis absorption spectra and PL spectra. The morphological analysis shows homogeneous RGO distribution on the TiO2 nanotube whereas elemental compositional analysis revealed the presence of all elements in the prepared catalyst. Visible light enhancement activity of the prepared catalyst after the incorporation of RGO was exposed by UV-Vis analysis due to its enhanced light absorption properties. Improved electron-hole separation rate was investigated for the RGO incorporated TNTs through PL analysis. The fruitful incorporation of the RGO with TNTs further affirmed by the increased photocatalytic activity by converting CO2 to CH4 that acquired enhanced CH4 production (9.27%) which is 1.81 times higher than the CH4 production rate obtained through TNTs (5.12%). Thus, this study induces a simple synthesis procedure to modify TNTs as a visible light active photocatalyst with the integration of RGO. Moreover, RGO-TNTs enhanced visible light activity were evaluated through the conversion of CO2 to CH4.