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150 W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150 W时,Ti_1-xV_xO₂薄膜的能带间隙值为 2.82 eV,其在2 h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 V targets (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 V target. 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 V target had different crystallinities. With the increase of power of V target, the relative contents of V element 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 V target was 150 W. The addition of V element 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 V target 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% RhB dyes 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.