Synthesis of WO₃@Graphene composite for enhanced photocatalytic oxygen evolution from water

Abstract

Abstract"Nano tungsten oxide (WO3) particles were synthesized on the surface of graphene (GR) sheets by using a simple sonochemical method. The obtained composite, WO3@GR, was characterized by X-ray diffraction, N-2 adsorption/desorption analysis, thermo-gravimetric analysis, Raman spectroscopy and UV-vis diffuse reflectance spectra measurements. It was found that chemical bonds between the nano WO3 particles and the GR sheets were formed. The average particle size of the WO3 was evidenced to be around 12 nm on the GR sheets. When used as photocatalyst for water splitting, the amount of evolved O-2 from water for the WO3@GR composite with 40 wt% GR inside was twice and 1.8 times as much as that for pure WO3 and mixed-WO3/GR, respectively. The excellent photocatalytic property of the WO3@GR composite is due to the synergistic effects of the combined nano WO3 particles and GR sheets. The sensitization of WO3 by GR enhances the visible light absorption property of WO3@GR. The chemical bonding between WO3 and GR minimizes the interface defects, reducing the recombination of the photo-generated electron-hole pairs. Furthermore, the GR sheets in the WO3@GR composite enhance electrons transport by providing low resistance conduction pathways, leading to improved photo-conversion efficiency. The methodology opens up a new way of obtaining photoactive GR-semiconductor composites for photodissociating water under visible light." Nano tungsten oxide (WO 3 ) particles were synthesized on the surface of graphene (GR) sheets by using a simple sonochemical method. The obtained composite, WO 3 @GR, was characterized by X-ray diffraction, N 2 adsorption/desorption analysis, thermo-gravimetric analysis, Raman spectroscopy and UV-vis diffuse reflectance spectra measurements. It was found that chemical bonds between the nano WO 3 particles and the GR sheets were formed. The average particle size of the WO 3 was evidenced to be around 12 nm on the GR sheets. When used as photocatalyst for water splitting, the amount of evolved O 2 from water for the WO 3 @GR composite with 40 wt% GR inside was twice and 1.8 times as much as that for pure WO 3 and mixed-WO 3 /GR, respectively. The excellent photocatalytic property of the WO 3 @GR composite is due to the synergistic effects of the combined nano WO 3 particles and GR sheets. The sensitization of WO 3 by GR enhances the visible light absorption property of WO 3 @GR. The chemical bonding between WO 3 and GR minimizes the interface defects, reducing the recombination of the photo-generated electron-hole pairs. Furthermore, the GR sheets in the WO 3 @GR composite enhance electrons transport by providing low resistance conduction pathways, leading to improved photo-conversion efficiency. The methodology opens up a new way of obtaining photoactive GR-semiconductor composites for photodissociating water under visible light.

Facile synthesis of decorated graphene oxide sheets with WO3 nanoparticles

“…3a), the G and D lines appear at 1582 and 1326 cm -1 , respectively. The value of 1582 cm -1 can be primarily attributed to the presence of single-layer GO sheets [18,[32][33][34][35]. As shown in Fig.…”

“…It was reported that the combination of WO 3 with graphene oxide sheets improves significantly its conductivity [17,25]. Several methods were studied to synthesize graphene-based nanocomposites, including grinding method [26], chemical synthesis [17,27] and sonochemical method [18]. In these methods, the nanoparticles usually attach to the GO sheets by formation of weak bond.…”

“…So far, several methods have been reported to attach nanoparticles to graphene oxide or graphene [16][17][18]. Nanostructure of tungsten trioxide (WO 3 ) is one of the metal oxide nanoparticles, which can modify the GO properties [17][18][19][20].…”

Controlled fabrication of Si nanoparticles on graphene sheets for Li-ion batteries

“…Similar phenomenon has been reported by many others. 17 The morphology of Si-Gr composite was revealed by SEM and TEM micrographs. GO shows a crumpled, stacked but expanded structure (Fig.…”

A Green Strategy to Synthesize Environment Friendly Metal Oxide Nanoparticles for Potential Applications – A Review

“…Controlling the size of the NPs is the major parameter for a variety of applications. Metal oxides can be synthesized by chemical methods such as sol-gel [1], hydrothermal [2], microwave [3], coprecipitation [4], sonochemical [5], solvothermal [6], and laser ablation method [7]. In the conventional methods, chemicals such as hydrazine monohydrate [8], cetyltrimethyl ammonium bromide [8], and polyvinyl pyrrolidone (PVP) [9] are used as reducing reagent and capping agent.…”