Facile synthesis of TaOxNy photocatalysts with enhanced visible photocatalytic activity†
Abstract
N-doped TaOxNy 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 TaOxNy sample sintered at 550 °C (TaOxNy-550), and the UV results show TaOxNy-550 has a rather strong absorption in the visible light region. The photocatalytic activities of TaOxNy are evaluated in hydrogen generation by water splitting and photodegradation of methyl orange. The N-doped TaOxNy 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.