A facile synthesis of CNTs/Cu2O-CuO heterostructure composites by spray pyrolysis and its visible light responding photocatalytic properties

Carbon nanotubes (CNTs)/Cu₂O-CuO composite powder was fabricated by a spray pyrolysis (SP) method. The copper acetate monohydrate (Cu(CH₃COO)₂·H₂O) solution within CNTs dispersion was used as a precursor. The influences of decomposition temperatures, concentration of Cu(CH₃COO)₂ solutions and CNTs mass fractions on the constituent phases and microstructures of the composite powder were investigated by XRD, FESEM, TEM, UV–Vis analysis methods. The results show that the composite powder prepared at 500?°C, with the concentration of 1.0?g/l Cu(CH₃COO)₂·H₂O and 30.0?wt.% CNTs mass fraction, has the best photocatalytic performance due to the numerous particles precipitated on the CNTs surface and lower recombination rate of the photogenerated electron-hole pairs. Furthermore, tentative mechanisms of the nucleation-growth and photodegradation properties were explored based on the microstructure and photocatalytic analysis.