3D macroporous TiO2 inverse opal binary and ternary composite materials and their photocatalytic activity

Abstract

This work reports the design of binary and ternary thin film based photocatalysts consisting of 3D macroporous inverse opal (IO) titanium dioxide, IO-TiO₂, embedded with gold nanoparticles (AuNPs) and cadmium sulfide (CdS) thin film. The composite materials thus created are IO-TiO₂–AuNPs, IO-TiO₂–CdS, and IO-TiO₂–AuNPs–CdS. The IO-TiO₂ 3D macroporous films are obtained by a liquid phase co-assembly method consisting of the simultaneous self-assembly of polystyrene (PS) nanospheres with a water soluble titania precursor. AuNPs and CdS thin films are integrated to the above IO-TiO₂ by in situ synthesis and successive ionic layer adsorption and reaction (SILAR) methods, respectively. The composite materials demonstrated very good photocatalytic proficiency against an organic pollutant analog under UV and visible lighting conditions. The morphologies of the photocatalysts were imaged with scanning electron microscopy (SEM). The elemental components were determined using energy dispersive X-ray (EDX) line analysis, and Raman spectroscopy. UV-visible spectroscopy was used to assess the photocatalytic efficiency of the composites in decomposing organic pollutant analog.