Cu/Ni助催化剂对TiO_2光催化制取苯酚性能的影响

Effect of Cu-Ni Cocatalyst on Visible Photocatalytic Activity of TiO_2 for Phenol Preparation

以Ti O2纳米粒子为主催化剂,采用"浸渍-还原法"构筑了铜、镍共负载的二氧化钛基光催化系统。以苯为起始原料,H2O2为氧化剂,研究了Cu/Ni助催化剂对Ti O2可见光催化制取苯酚性能的影响并对Cu/Ni助催化剂的作用机制进行了探讨。结果表明,在可见光照射下,纯Ti O2纳米粒子对苯氧化制取苯酚反应没有催化活性。铜、镍的引入可以明显地增强Ti O2可见光催化制取苯酚的活性。当使用负载有铜、镍的Ti O2作为催化剂时,苯酚的产率可达到18%。结果还表明Cu、Ni之间存在着很强的协同作用。在该协同作用下,Cu、Ni共负载的Ti O2纳米粒子表现出了较单一金属负载的Ti O2纳米粒子高得多的光催化活性。

The Cu-Ni co-modified TiO2-based photocatalytic system was fabricated using TiO2 nanoparticles as the main catalyst component by an impregnation process followed by a reduction procedure. The effect of Cu-Ni cocatalyst on the visible photocatalytic activity of TiO2 for phenol preparation was studied using benzene as the starting material and hydrogen peroxide as the oxidant. The action mechanism of Cu-Ni cocatalyst for the photocatalytic activity of TiO2 nanoparticles is discussed. The results show that the pure TiO2 nanoparticles do not have photocatalytic activity for the phenol production from benzene under visible light irradiation. In contrast, the photocatalytic activity of TiOa nanoparticles can be enhanced obviously due to the introduction of Cu and Ni. The yield of phenol is 18% when the Cu-Ni co-modified TiO2 nanoparticles are used as a photocatalyst. Moreover, there exists noticeable synergistic effect between Cu and Ni. The Cu-Ni co-modified TiO2 nanoparticles exhibit much higher photocatalytic activity in comparison with that of the Cu or Ni alone modified ones due to the synergistic effect. These results imply that the cheap cocatalyst with outstanding performance than that of noble metals may be prepared by taking advantage of the synergistic effect between various metals.