Preparation, characterization and photoluminescence of Zn 2+ /GaOOH nanowires

Gallium oxide hydroxide (GaOOH) is a kind of semiconductor material with broad-band gap and has extensive potential applications in the fields such as photocatalytic degradation of organic dyes, direct methanol fuel cell, lithium ion battery, bioluminescent imaging and so on. In our study, Zn2+/GaOOH nanowires have been synthesized via a facile and controllable hydrothermal method with zinc acetate and gallium nitrate as reactants and ethylenediaminetetraacetic acid disodium salt(Na2Y)as template. The products were characterized by XRD、SEM、HRTEM and EDS techniques. The length of the as-prepared uniform Zn2+/GaOOH nanowires is up to several micrometers and the diameter is about 100 nm. Zn2+/GaOOH is single crystalline and grew along crystalline direction . The phase and morphology of Zn2+/GaOOH were affected by reactants and their amounts. Keeping the reactant amount of 1.5 mmol gallium nitrate stand, Zn2+/GaOOH nanowires formed with 1.0 mmol zinc acetate and 1.0~1.7 mmol Na2Y, while spinel ZnGa2O4 nanoparticles obtained with 0.5 mmol Na2Y. When the reactant amount of zinc acetate was changed to 2.0 mmol, only spinel ZnGa2O4 nanoparticles can be obtained with the reactant amount of 1.5 mmol gallium nitrate. The detail of the effects of the products by Zn∶Ga∶Y mole ratios on the phase and morphology was studied, showing the forming condition of phase-pure and uniform Zn2+/GaOOH nanowires with the Zn∶Ga∶Y mole ratio of 2∶3∶3. The result of photoluminescence determination showed that Zn2+/GaOOH nanowires exhibit strong PL emission in the blue-green wavelength range, attribute to the recombination of the defect-related excitations through an excitation-excitation collision process. The strongest PL emission is at 469 nm with the excitaton of 214 nm. The intensity of the emission peak at 469 nm rises with the blue-transiton of excitation wavelength. Zn2+/GaOOH nanowires showed higher intensity of the emission peak at 469 nm by the excitation wavelength of 226 nm, accompanied with ZnGa2O4 nanoparticles, indicating more excellent photoluminescence performance.