钒-氮共掺杂TiO_2的合成、表征及光催化性能

Synthesis,characterization and Degradation performance of V-N-TiO_2 nanoparticle photocatalysts

以偏钒酸铵作为钒源、二乙醇胺作为氮源,采用溶胶-凝胶法合成了钒-氮共掺杂TiO2.通过XRD、UV-Vis、TEM、XPS、BET等表征手段,对光催化剂的晶体结构及形貌、紫外可见光响应特性、比表面积、表面元素及存在形式进行分析,探讨钒氮共掺杂TiO2的影响机制.以苯酚为污染物,评价其在紫外光及可见光下的光催化活性.结果显示,所合成的光催化剂均为锐钛矿,钒氮共掺杂能够增大其比表面积,并使光吸收范围拓展至可见光区,N以O—Ti—N、Ti—O—N结构存在于钒氮共掺杂TiO2中,V以V5+的形式存在,钒-氮共掺杂TiO2在紫外光下对苯酚降解速率是TiO2的3.18倍,在可见光下对苯酚的降解速率为TiO2的2.56倍,重复使用7次后,钒-氮共掺杂TiO2对苯酚的降解率仍可以达到99%以上.

V-N-TiO2 nanoparticle were synthesized by sol-gel method,with diethanolamine as nitrogen source,and ammonium metavanadate as vanadium source.The samples were characterized by XRD,UV-Vis,TEM,XPS,BET etc,and their photocatalytic activity was investigated in the degradation of phenol.The result shows that all the samples were anatase form.Vanadium and nitrogen co-doping increased the specific surface area of the material and expanded the light absorption to the visible region.The result of XPS shows that nitrogen in V-N-TiO2 is in the form of O—Ti—N and Ti—O—N,and vanadium in V-N-TiO2 is in the form of V5＋.V-N-TiO2 demonstrated high catalytic activity in the degradation of phenol under UV-light（3.18 times higher than TiO2） and visible light（2.56 times higher than TiO2）.Furthermore,the degradation rate of phenol by V-N-TiO2 catalyst reached 99% after being re-used for 7 times.