Morphology Controlled Deposition of Vanadium Oxide (VO x ) Nanoparticles on the Surface of Highly Reduced Graphene Oxide for the Photocatalytic Degradation of Hazardous Organic Dyes.

Semiconducting nanomaterials based heterogeneous photocatalysis represent a low-cost, versatile technique for environmental remediation, including pollution mitigation, energy management and other environmental aspects. Herein, we demonstrate the syntheses of various heterogeneous photocatalysts based on highly reduced graphene oxide (HRG) and vanadium oxide (VO x )-based nanocomposites (HRG-VO x ). Different shapes (rod, sheet and urchin forms) of VO x nanoparticles were successfully fabricated on the surface of HRG under solvo-/hydrothermal conditions by varying the amount of water and ethanol. The high concentration of water in the mixture resulted in the formation of rod-shaped VO x nanoparticles, whereas increasing the amount of ethanol led to the production of VO x sheets. The solvothermal condition using pure ethanol as solvent produced VO x nano-urchins on the surface of HRG. The as-prepared hybrid materials were characterized using various spectroscopic and microscopic techniques, including X-ray diffraction, UV-vis, FTIR, SEM and TEM analyses. The photocatalytic activities of different HRG-VO x nanocomposites were investigated for the photodegradation of methylene blue (MB) and methyl orange (MO). The experimental data revealed that all HRG-VO x composite-based photocatalysts demonstrated excellent performance toward the photocatalytic degradation of the organic dyes. Among all photocatalysts studied, the HRG-VO x nanocomposite consisting of urchin-shaped VO x nanoparticles (HRG-VO x -U) demonstrated superior photocatalytic properties towards the degradation of dyes.