Study On Low-temperature Liquid Phase Synthesis And Photocatalytic Proprety Of Zn-doped Micro/nano-sized Cu₂O

Cu2O is a typical semiconductor materials with a more wide band gap. It has been applied in many fields and attaracted serious concern of materials scholar. In this work, the best reaction condition of micro/nano-sized Cu2 O and its doping was discussed, the investigation in its photocatalytic property and charge/discharge property was also conducted.Firstly, using cupric acetate as copper source, glucose as the reducing agent, sodium citrate as complexing agent and PVP as the surfactant, micro/nano-sized Cu2 O were successfully prepared by a low temperature liquid phase method. The structures and morphologies of as-prepared samples were characterized by XRD, SEM, TEM and PL. The influences of reaction temperature, reducing agent, complexing agent, pH value and the surfactant were also discussed. Cu2 O samples with different morphology were synthesized by adjusting the dosage of surfactant. Results indicated that the morphology change can enhance photoactivity of micro/nano-sized Cu2 O, which the highest degradation rate for MB solution with an initial concentration of 10mg·L-1 can reach 71.01%. For the later SCS study, the charge/discharge property of Cu2 O samples was also tested, which the capacitance is 284.2 mF /cm2.To further enhance the visible light photoactivities of Cu2 O samples, on the basis of the early research on the controlled synthesis of Cu2 O micro/nanocrystals, using Zn(NO3)2 as doping agent, Zn-doped Cu2 O micro/nanocrystals was successfully prepared by low temperature liquid phase method. The physicochemical properties of as-prepared samples were characterized by XRD, SEM, EDS and UV-vis. The photocatalytic activities of the samples were evaluated by degradation of MB under visable light irradiation. Results indicated that the degradation rate for MB solution with an initial concentration of 10mg·L-1 reached 90.47% in the presence of Zn-doped Cu2 O after visable light irradiation for 2 h. The enhanced photoactivity of samples could be attributed to following aspects: the broaden of band gap reduced recombination of e-/h+, increased surface hydroxyl, as well as improved surface textural properties including deecrease in crystalline size and the formation of p-n heterojunction. Furthermore, the reusability of the samples and the likely mechanisms were also investigated.