Synthesis, defect characterization and photocatalytic degradation efficiency of Tb doped CuO nanoparticles

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Japan, 2017-11, Vol.28 (11), p.3026-3038
• Main Authors: Vimala Devi, L., Sellaiyan, S., Selvalakshmi, T., Zhang, H.J., Uedono, A., Sivaji, K., Sankar, S.
• Format: Article
• Language: English
• Subjects: Band gap; Defects; PAS; Photocatalyst; Tb doped CuO
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2017.09.013

[Display omitted] •CuO and Tb doped CuO were synthesized by solution-combustion method.•Crystal structure, functional group and optical property were studied.•Type of defects and its effect on photodegradation of MB and MO were investigated.•Effect of dopant on lattice defect was examined at different temperature.•Valence state of electron and surface area were also studied. Monoclinic undoped and Tb doped CuO are prepared by solution combustion method and annealed at different temperatures. The effect of annealing and doping on their structural and optical properties of CuO are examined using XRD, FTIR and DRS. The surface and lattice defects in CuO and Tb doped CuO is analyzed qualitatively and quantitatively using positron lifetime and Doppler broadening spectroscopy. The average positron lifetime and electron momentum (energy) S parameter increases owing to the number of vacancies in the CuO lattice upon doping and decreases with increasing temperature. The migration of vacancies from grain to grain boundary region is observed at 600°C annealed samples. At 800 °C, the overall behavior of lifetime value denotes that the vacancy type defect is recovered, cluster vacancy and microvoids exists with reducing size. The photocatalytic performance of undoped and Tb doped CuO on degradation of methylene blue (MB) and methyl orange (MO) is investigated under visible light for two different lamp power and dye concentration. The influence of annealing temperature and dopant ion on the efficiency is also elaborated. Enhanced photocatalytic efficiency in Tb doped CuO is observed upon annealing. X-ray photoelectron spectroscopy (XPS) result indicates that the valence states of Cu, O and Tb ions exist at the surface of the particles. Brunauer–Emmett–Teller N2 adsorption–desorption analyses were employed to characterize specific surface area and porosity of Tb doped CuO. The doped CuO with pore size of about ∼34nm have a surface area of 16–28m2/g. The surface area effect plays an important role in the enhanced catalytic performance on Tb doped catalysts.