室温下制备以{211}晶面为主的Ti1-xVxO2薄膜及其可见光催化性能

以金属Ti和V作为靶材,采用直流反应共溅射技术在室温下制备了以{211}晶面为主的锐钛矿相Ti_1-xV_xO₂薄膜,研究了不同V靶功率对Ti_1-xV_xO₂薄膜的薄膜成分、晶相结构和可见光催化性能的影响。研究表明,Ti_1-xV_xO₂薄膜的晶相结构为锐钛矿相,择优取向为(211),而结晶度受V靶功率的影响。随着V靶功率的增加,薄膜中V元素含量逐渐增加,同时,晶粒和沉积速率也逐渐增加。另外,当V靶功率为150W时,薄膜的表面粗糙度值有一个最大值。V的掺杂导致薄膜的能带间隙变窄,对光的吸收向可见光区偏移,从而有效地改善了薄膜的可见光催化能力。当V靶功率为150W时,Ti_1-xV_xO₂薄膜的能带间隙值为2.82eV,其在2h的可见光照射下分解了80%的RhB染料。这被归结于能带间隙窄,高能晶面{211}和结晶度高的共同作用。

Visible-Light Photocatalytic Properties of Ti1-xVxO2 Films with Dominant {211} Facets Deposited at Room Temperature

Ti_1-xV_xO₂ films with dominant {211} facets were deposited by direct current reactive magnetron sputtering with Ti and Vtargets (99.99% purity) at room temperature. We study the composition, crystal structure and visible-light photocatalytic properties of the films as a function of power of Vtarget. The results showed that crystal phase of Ti_1-xV_xO₂ films was anatase with (211) preferred orientation, but the films deposited at different power of Vtarget had different crystallinities. With the increase of power of Vtarget, the relative contents of Velement increased gradually, meanwhile, crystal grain and deposition rate also increased. In addition, the surface roughness of the film had a maximum value when the power of Vtarget was 150 W. The addition of Velement gives rise to the band gap of TiO₂ films narrowing down. As a result, the optical absorption edge of the Ti_1-xV_xO₂ films shifts towards visible-light zone, improving the visible-light photocatalytic activity of the films. When the power of Vtarget came to 150 W, the value of band gap of the Ti_1-xV_xO₂ film was about 2.82 eV, and the film degraded ~80% RhBdyes after 2 h visible-light irradiation. This can be attributed to the synergistic effect of narrow band gap, high energy facet {211}, and high crystallinity.