Facile Fabrication Of RGO/N-GZ Mixed Oxide Nanocomposite For Efficient Hydrogen Production Under Visible Light

A series of reduced graphene oxide and N-doped GaZn mixed oxide nanocomposities (RGO/N-GZ) were fabricated by a facile chemical route. The adopted hydrothermal route results in reduction of graphene oxide (GO) to RGO as well as well decoration of nanostructure N-GZ mixed oxide on RGO sheets. 4 wt % loading of RGO to N-doped GZ mixed oxide showed highest amount of hydrogen production with an apparent quantum efficiency of 6.3% under visible light irradiation even if in absence of Co-catalyst. PL, TRPL, photocurrent measurement, and BET surface area analysis of N-GZ mixed oxide/RGO composite give the evidence for effective minimization of electron–hole recombination in comparison to neat N-GZ mixed oxides. The highest photocatalytic activity N-GZ/4RGO for hydrogen production is well explained on the basis of low PL intensity, longer average decay time (value of ⟨τ⟩ for N-GZ and 4RGO/N-GZ is 3.74 and 5.76 ns, respectively), high photocurrent generation (50× more than N-GZ), large surface area and cocatalytic behavior of RGO

Green Synthesis of Fe₃O₄/RGO Nanocomposite with Enhanced Photocatalytic Performance for Cr(VI) Reduction, Phenol Degradation, and Antibacterial Activity

Herein, we report a novel single-step hydrothermal synthesis of a photocatalytically stable and magnetically separable g-Fe₃O₄/RGO nanocomposite in the presence of <i>Averrhoa carambola</i> leaf extract as a natural surfactant for multipurpose water purification application. The <i>Averrhoa carambola</i> leaf extract played a major role in the modification of structural, optical, and electronic properties of the Fe₃O₄ nanoparticle. At room temperature, the g-Fe₃O₄/2RGO nanocomposite showed 97% and 76% of Cr­(VI) reduction and phenol degradation, respectively. The higher activity of g-Fe₃O₄/2RGO was attributed to the in situ loading of RGO, and the synergism developed between RGO and the super magnetic Fe₃O₄ nanoparticle results in better separation of photoexcited charge carriers (e^–/h⁺) which was concluded from photoluminescence and photocurrent measurements. Further, the g-Fe₃O₄/2RGO nanocomposite showed better antimicrobial activity against three bacterial pathogens such as <i>Staphylococcus aureous</i> (MTCC-737), <i>Bacillus subtilis</i> (MTCC-736), and <i>Escherichia coli</i> (MTCC-443) compared to GO with respect to a standard antibiotic (30 μg)