负载型Cu-BiVO_4复合光催化剂的制备及可见光降解气相甲苯

Preparation of Supported Cu-BiVO_4 Photocatalyst and Its Application in Oxidative Removal of Toluene in Air

以P123为软模板,在200 oC采用水热法合成了BiVO4粉体,再用浸渍法制备Cu改性BiVO4催化剂,然后通过硅溶胶将其分散负载于金属不锈钢丝网上.考察了催化剂负载量和Cu复合量对该样品在可见光下催化氧化去除气相甲苯效能的影响.结果表明,催化剂涂覆两层(负载量约为2～2.2 mg/cm2,以SiO2,BiVO4和Cu计),Cu复合量为5.0%时活性最高,反应5 h后,对初始浓度为80 mg/m3左右的甲苯最高去除率由纯BiVO4的34%提高到90%.采用X射线衍射、扫描电镜、X射线光电子能谱和紫外-可见光谱等表征手段对催化剂的结构性质进行了表征.结果表明,Cu的复合使可见光吸收带发生红移,吸收强度也有较大幅度的提高.

Visible-light photocatalysts bismuth vanadate（BiVO4）,hydrothermally prepared at 200 oC using P123 as template,and Cu-doped BiVO4 by impregnation and calcination,were dispersed in a tetraethyl orthosilicate sol and than loaded onto stainless steel mesh followed by drying.Photocatalytic removal of toluene in air using these photocatalysts was investigated for different Cu dopings and catalyst loadings.The catalyst with two layers of coated 5.0%Cu-BiVO4 catalyst（the total of SiO2,BiVO4,and Cu was approximately 2.0–2.2 mg/cm2） has the highest catalytic activity.After 5 h,the removal rate of toluene at 80 mg/m3 initial concentration was enhanced from 34% with pure BiVO4 to 90%.The composite photocatalysts were characterized by X-ray diffraction,scanning electron microscopy,X-ray photoelectron spectroscopy,and ultraviolet-visible absorption spectroscopy.The Cu-BiVO4 catalyst has a significant red-shift in the absorption band in the visible region,and the absorption intensity increases greatly for the composite catalyst containing 5.0% Cu.