Rapid growth of zinc oxide nanorods on kanthal wires by direct heating method and its photocatalytic performance in pollutants removal

Immobilization of photocatalysts on supporting substrates to prevent the loss and deterioration of photocatalytic performances is an issue to be addressed by researchers. However, the common synthesis techniques such as chemical vapour deposition, sol-gel, or hydrothermal are time- and cost inefficient. A lot of heat is loss to environment when the heat generated outside the reactor is transferring into the reactor and precursor solution. In this work, ZnO nanorods were grown on kanthal wires using direct heating (DH) technique. DH technique offers many advantages as compared to common synthesis techniques such as chemical vapor deposition, sol–gel and hydrothermal to produce ZnO nanorods. The heat was generated directly on the substrate itself, providing effective heating, low electric consumption (≤0.060 kWh), and rapid synthesis (15 min) of ZnO nanorods. The presence of ZnO nanorods on kanthal wires are verified by XRD, FESEM, TEM/HRTEM, XPS and RTPL analyses. The ZnO nanorods demonstrated good photocatalytic performance in degradation of RhB dye and heavy metal ions under UV light. Thus, DH is a potential synthesis technique for mass production of wastewater treatment module.