Enhancement in NO₂ and H₂-Sensing Performance of CuxO/TiO₂ Nanotubes Arrays Sensors Prepared by Electrodeposition Synthesis

The Cu_xO/TiO₂ nanotubes arrays are fabricated in two stages. Firstly, TiO₂-NTs are grown by the Ti-foil anodization process and then annealed for 2h at 500 ^oC. Subsequently, Cu_xO thin film was deposited with different deposition times on the nanotubes by electrochemical cathodic reaction, then heated twice, once at 200 ^oC in the air and then at 300 ^oC in the closed furnace for 2 h, respectively. Pure-TNT and Cu_xO/TNTs heterostructure are characterized by XRD, FE-SEM, EDX, Hall effect, and as a gas sensor. Results show that the gas sensor (CuO_x=1 /TiO₂ for NO₂ and H₂ gases) prepared at the time (1 min) is higher than the pure TiO₂-NTs and also higher than Cu_x=2O/TiO₂   which were synthesized at various times 3, 5, 7, and 10 mins.