Facile synthesis of TaOxNy photocatalysts with enhanced visible photocatalytic activity

Abstract

N-doped TaO_xN_y is prepared using ethylenediamine as the nitrogen source by a sol–gel method. The obtained samples are subsequently calcined at 500–900 °C. XRD analysis and XPS survey indicate the presence of immature TaO₂ (Ta⁴⁺) in the N-doped TaO_xN_y sample sintered at 550 °C (TaO_xN_y-550), and the UV results show TaO_xN_y-550 has a rather strong absorption in the visible light region. The photocatalytic activities of TaO_xN_y are evaluated in hydrogen generation by water splitting and photodegradation of methyl orange. The N-doped TaO_xN_y sample sintered at 550 °C shows the highest H₂ generation rate of 3.12 mmol g⁻¹ h⁻¹, and only 3.1% methyl orange is left after 90 min irradiation. Such photocatalytic activities are comparable to the conventional nitrogen-doped titania.