B离子掺杂TiO2催化剂(TiO(2-x)Bx)光催化活性的研究

Study on Photocatalytic Activity of Boron Doped TiO_2 Catalyst (TiO_(2-x)B_x)

采用溶胶-凝胶法制备出纳米TiO2和TiO2-xBx催化剂.光催化实验证明,TiO2-xBx催化剂的紫外、可见光催化活性均高于TiO2.XRD,XPS和Raman结果表明,B离子是以取代式掺杂占据了TiO2的O2-的晶格位置.UV-Vis和PL谱的结果表明,B离子的2p轨道与O的2p轨道形成混合价带,产生可见光响应,B离子的掺入有效地阻止了光生载流子的复合,促进了其分离,是TiO2-xBx催化剂紫外、可见光催化活性提高的主要原因.

Samples of pure TiO2 and TiO2-xBx were obtained with Ti（OC4H9）4 by sol-gel methods. Compared with the pure TiO2, the samples of TiO2-xBx exhibited higher photocatalytic activity under both ultraviolet and visible light irradiation. The reasons were discussed, based on the characterization with XRD, Raman, XPS, UV-Vis and PL spectra. The lattice O is substituted by B, and the orbital of B2p is mixed with O2p orbitals, which is responsible for the band gap narrowing. The raise of the photocatalytic activity is chiefly because B doping enhanced the absorption of visible light, and promoted the separation of photogenerated carriers.