Microwave-assisted growth of WO3·0.33H2O micro/nanostructures with enhanced visible light photocatalytic properties

Abstract

Various micro/nanostructured WO₃·0.33H₂O crystallites were successfully controlled by employing microwave heating under different conditions. By using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and high resolution transmission electron microscopy, the phase and morphology of the products were identified. Comparing the as-prepared crystallites under conventional and microwave heating processes found that microwave heating may play a crucial role to initiate the oriented growth of orthorhombic WO₃·0.33H₂O micro/nanostructures. Moreover, these oriented structures exhibit clearly improved photocatalytic activity over the structures prepared under the conventional heating process. By applying the multi-site complexation model, the improved photocatalytic properties were found to relate to the exposure of high surface acidity orthorhombic WO₃·0.33H₂O crystallites, which originate from the oriented growth of microstructures prepared under the microwave heating process.