TiO2/Cu2O/CuO multi-nanolayers highly sensitive toward volatile organic compounds (VOCs) and H2 have been grown in various thicknesses by a cost-effective reproducible combined spray–sputtering–annealing approach. The ultrathin TiO2 films were deposited spray pyrolysis on top of sputtered–annealed Cu2O/CuO nanolayers to enhance their gas sensing performance improve protection against corrosion ...