N-dope d NaTaO3 synthesize d from a hydrothermal method for photocatalytic water splitting under visible light irradiation

作者：Hu Che Chia; Huang Hui Hsin; Huang Yu Chi

来源：Journal of Energy Chemistry, 2017, 26(3): 515-521.

DOI：10.1016/j.jechem.2016.12.002

• Photocatalysis
• H-2 production
• N-doped NaTaO3
• Hydrothermal method
• Visible light

NaTaO3-xNx catalysts were synthesized by a hydrothermal (H) and a solid-state (S) methods in this study. The H-and S-NaTaO3-xNx samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible (UV-vis) diffuse reflectance spectroscopy, and photoluminescence (PL) spectroscopy. The XRD patterns of the H-and S-samples showed peaks indexed to the pure phase of perovskite NaTaO3 and minor peaks assignable to Ta3N5 at various synthesis temperatures. Substitution of oxygen by nitrogen ions causes the light absorption of the H-and S-NaTaO3-x N-x samples to be extended to the 600-650 nm region, thus making the samples visible-light active. The NaTaO3-x N-x samples exhibited photocatalytic activity for H-2 and O-2 evolution from aqueous methanol and silver nitrate solutions under visible-light irradiation. The UV-vis and PL spectra of the Hand S-catalysts revealed the presence of cationic vacancies and reduced metallic species, which acted as recombination centers. These results demonstrated that the preparation method plays a critical role in the formation of defect states, thereby governing the photocatalytic activity of the NaTaO3-x N-x catalysts.

• 出版日期2017-5