Titanium (IV) oxide composite hollow nanofibres with silver oxide outgrowth by combined sol–gel and electrospinning techniques and their potential applications in energy and environment
Tanatchporn Sirimekanont, Pitt Supaphol, Korakot Sombatmankhong
Abstract
Abstract A two-dimensional nanostructure composed of Ag 2 O nanobranches attached to TiO 2 hollow nanofibres (denoted as 2D Ag 2 O/TiO 2 ) was successfully prepared via sol–gel and coaxial electrospinning techniques. The Ag/TiO 2 hollow nanofibres were fabricated and calcined in ambient air at 500 °C. By calcination, the removal of organic materials and the formation of anatase TiO 2 were achieved with a well-retained hollow structure. The embedded Ag nanoparticles functioned as seeds for the Ag 2 O outgrowth on the TiO 2 surface using a hydrothermal treatment at different times and temperatures, which caused the change in physical appearance, surface area, and electrical conductivity of 2D Ag 2 O/TiO 2 . A high quantity of Ag 2 O nanobranches on TiO 2 nanofibres were obtained with increasing the temperature from 110 to 115 °C and the reaction time to 60 min. Consequently, the electrochemical active surface area (EASA) value was maximised to 65.25 cm 2 per cm 2 with an enhanced electrical conductivity of 91.3 ± 3.9 × 10 −2 S cm −1 . Further studies on the depth-profiles of Ag, Ti, and O revealed the presence of Ag 2 O attached to the core structure of TiO 2 . The photoelectrochemical and photocatalytic tests confirmed the excellent physical and electrochemical properties of 2D Ag 2 O/TiO 2 (@115 °C, 60 min) for use in energy and environmental applications. Graphical Abstract