Nano gold supported on ordered mesoporous WO3/SBA-15 hybrid nanocomposite for oxidative decolorization of azo dye

• Au nanoparticles were loaded in WO3/SBA-15 using wet impregnation process.
• Nanocomposite catalytic performance was evaluated on Methyl orange degradation.
• Effect of pH, catalyst dosage and dye concentration were evaluated.
• Under visible light, 98% MO dye was degraded in 30 min of illumination time.

A facile approach was embraced to synthesize heterogeneous catalysts using ordered mesoporous silica SBA-15 as framework, WO3 as auxiliary and Au nanoparticles as the catalytic active sites, signified as Au-WO3/SBA-15. Characterization results show that the Au nanoparticles were found dispersed uniformly inside the pore channels instead of aggregation outside the surface of SBA-15. Catalytic degradation studies for advanced oxidation processes (AOPs) demonstrate that Au-WO3/SBA-15 catalysts can efficiently degrade (>98%) high concentration of dye pollutants (C = 0.3 g l−1) within 30 min and can retain a good degradation efficiency at a pH value of 2 when using Methylene orange (MO) as the model toxin. The excellent AOP synergist performance could be ascribed to the combined effects, including enhanced reactant adsorption by the mesoporous structure of SBA-15, well-distribution of WO3 inside the mesopores and reduced electron–hole recombination rates due to Au loading. Our work here shows a basic method to synthesize ordered mesoporous heterogeneous catalyst with well dispersed nano-sized catalytic active sites for AOPs by using WO3 as the auxiliary agent.

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