Abstract

Creating mesoporous architecture on the surface of metal oxides without using pore creating agent is significant interest in electrochemical sensors because these materials act as an efficient electron transfer process between the electrode interface and the analytes. Recent advances in mesoporous titanium dioxide (TiO2)-based materials have acquired extraordinary opportunities because of their interconnected porous structure could act as a host for doping with various transition metals or heteroatoms to form a new type of heterojunction. Herein, a simple method is developed to synthesize mesoporous copper oxide (CuO) decorated on TiO2 nanostructures in which homogenous shaped CuO nanocrystals act as dopants decorated on the mesoporous structure of TiO2, resulting in p-n heterojunction nanocomposite. The TiO2 particles exhibit a mesoporous structure with a pore volume of about 0.117 cm3/g is capable to load CuO nanocrystals on the surface. As a result, large pore volume 0.304 cm3/ g is obtained for CuO-TiO2 heterojunction nanocomposite with the loading of uniform-shaped CuO nanocrystals on the mesoporous TiO2. The resulting CuO-TiO2 nanocomposite on modified glassy carbon (GC) electrode exhibits good electrochemical performance for oxidation of catechol with the observation of strong enhancement in the anodic peak potential at +0.36 V. The decrease in the overpotential for the oxidation of catechol when compared to TiO2/GC is attributed to the presence of CuO nanocrystals providing a large surface area, resulting in wide linear range 10 nM to 0.57 mu M. Moreover, the resultant modified electrode exhibited good sensitivity, selectivity and reproducibility and the sensor could able to determine the presence of catechol in real samples such as lake and river water. Therefore, the obtained CuO-TiO2 nanocomposite on the modified GC delivered good electrochemical sensing performance and which could be able to perform a promising strategy for designing various metal oxide doped nanocomposites for various photochemical and electrocatalytic applications.