Solvothermal synthesis of N-doped ZnO microcrystals from commercial ZnO powder with visible light-driven photocatalytic activity

Abstract

N-doped ZnO microcrystals were fabricated by a one-step low temperature (140°C) solvothermal route from commercial ZnO (A.R), HNO3, and ethanol, in which HNO3 was utilized as the nitrogen source. The structure, composition, BET specific surface area and optical properties of N-doped ZnO sample were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, wavelength dispersive X-ray fluorescence, field emission scanning electron microscopy, N2 adsorption–desorption isotherms, Raman and UV–vis diffuse reflectance spectroscopy. The photocatalytic results demonstrated that as-synthesized N-doped ZnO microcrystals possessed much higher photocatalytic activity than N-doped TiO2 (which was solvothermally synthesized using P25 TiO2 and HNO3) and commercial pure ZnO in the reduction of aqueous Rhodamine 6G under visible light (λ>420nm) irradiation. Moreover, the photocatalytic results indicated that the as-synthesized N-doped ZnO was a kind of promising photocatalyst in remediation of water polluted by some chemically stable azo dyes under visible light irradiation.