Hao Hua

Preparation and Improved Photocatalytic Activity of WO3·0.33H2O Nanonetworks

Multi-structural tungsten oxide (WO3·0.33H2O) samples were prepared using a hydrothermal method in the presence of different salts Na2SO4 and CaCl2 respectively. The experimental results showed that pH value of the reaction solution greatly affects crystal morphology of the final products. To explore the photocatalysis originated from nanonetwork hierarchical structure, the photodegradation of methylene blue was carried out under simulated sunlight irradiation. The photocatalytic activity of the WO3·0.33H2O nanonetworks was compared with that of the nanoplates, and the former showed a higher photocatalytic activity owing to its novel hierarchical structure. Our investigation demonstrates that nanonetwork hierarchical structure can promote sunlight absorption due to higher specific surface area.Graphical abstract

Three-dimensional Ag{sub 2}O/WO{sub 3}·0.33H{sub 2}O heterostructures for improving photocatalytic activity

Three-dimensional Ag2O/WO3·0.33H2O heterostructures were fabricated by loading Ag2O nanoparticles on WO3·0.33H2O 3D networks via a simple chemical precipitation method. The Ag2O/WO3·0.33H2O heterostructures exhibited much enhanced photocatalytic activity for the degradation of methylene blue (MB) under simulated solar light irradiation. The optimal molar ratio of Ag2O and WO3·0.33H2O is 1:2. The outstanding photocatalytic activity of the Ag2O/WO3·0.33H2O can be attributed to its large surface area of the three-dimensional networks, the enhanced sunlight absorption and the prevention of electrons–holes combination from the heterostructures. The experiment result demonstrates that wide band gap semiconductor (WO3·0.33H2O) modified by narrow band gap metal oxide (Ag2O) with 3D architecture will be an effective route to enhance its photocatalytic activity.