负载金的掺氮二氧化钛的制备及其可见光催化性能

以纳米管钛酸为前驱体,采用水热法先制备得到新型N掺杂二氧化钛,然后用沉积沉淀法在N掺杂二氧化钛表面负载微量贵金属Au,制备得到负载Au的掺N二氧化钛.利用TEM、XRD、XPS、ESR和DRS等手段研究了样品的形貌、晶体结构、元素化学态和光谱吸收性质.样品光催化活性通过可见光催化降解丙烯进行评价,结果表明,样品N-TiO₂和Au/N-TiO₂具有明显的可见光(λ≥420 nm)催化活性.ESR结果表明,掺氮过程中生成的束缚单电子的氧空位是样品具有可见光响应的原因.

Preparation of Gold-Modified Nitrogen-Doped TiO2 and Its Visible Light Photocatalytic Activity

N-doped TiO2 was obtained from nanotube titanic acid and aqueous ammonia by hydrothermal method,and then gold-modified N-doped TiO2 was prepared using deposition-precipitation method to deposit Au on the surface of N-doped TiO2.The physicochemical properties of resultant N-doped or Au/N-doped TiO2 samples were investigated by means of transmission electron microscopic(TEM),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),diffuse reflectance spectra(DRS),and electron spin resonance(ESR).The photocatalytic activity was evaluated by monitoring oxidation of propylene under visible light irradiation.Results indicated that N-TiO2 and Au/N-TiO2 showed obviously the visible light(λ≥420 nm) photocatalytic activity.The visible light sensitization was ascribed to the formation of single-electron-trapped oxygen vacancies.