TCN-TiO_(2)/Zn(CH_(3)COO)_(2)-ACF复合材料吸附耦合光催化降解烷烃类VOCs性能研究

ADSORPTION-COUPLED PHOTOCATALYTIC DEGRADATION OF ALKANE VOCs BY TCN-TiO_(2)/Zn(CH_(3)COO)_(2)-ACF COMPOSITES

采用Zn(CH_(3)COO)_(2)通过超声-真空浸渍法对活性炭纤维(ACF)进行改性,通过水热横向热剥离法制备了管状氮化碳(TCN),并将其与TiO_(2)复合并负载于改性ACF上制备成TCN-TiO_(2)/Zn(CH_(3)COO)_(2)-ACF复合材料。应用扫描电子显微镜、透射电子显微镜、X射线衍射、N_(2)吸附-脱附、X射线光电子能谱、傅里叶变换红外光谱、紫外-可见分光光谱、光致发光光谱、光电流响应曲线对复合材料进行表征,并对复合材料催化正己烷降解的机理与降解率进行了研究。结果表明:光照条件下,TCN质量分数为4%的复合材料对正己烷的降解效果最好,其最佳的制备条件为负载2次、450℃下煅烧。采用此条件所制复合光催化剂,在体积空速为1000 h-1的条件下,质量浓度为200 mg/m^(3)的正己烷气体降解率可达到87.9%。采用Zn(CH_(3)COO)_(2)对ACF进行改性,使ACF吸附能力得到增强;TCN与TiO_(2)复合形成异质结,降低了电子-空穴复合率,从而提高复合光催化剂的吸附耦合光催化效率。

The tubular carbon nitride(TCN)was prepared by hydrothermal lateral thermal stripping method,the ACF was successfully modified with Zn(CH_(3)COO)_(2) by ultrasonic-vacuum impregnation method,TCN-TiO_(2)/Zn(CH_(3)COO)_(2)-ACF composites were prepared by loading TiO_(2) onto modified ACF.The composites were characterized by SEM,TEM,XRD,BET,XPS,FT-IR,UV-vis,PL,and I-T photocurrent response,and the degradation mechanism and degradation efficiency of n-hexane were studied.The results showed that the degradation effect of n-hexane was best when the mass fraction of TCN was 4%under light conditions,and the optimum preparation conditions were calcination at 450℃after loading twice.Under these conditions,the degradation rate of n-hexane gas with concentration of 200 mg/m^(3) at a space velocity of 1000 h-1 could reach 87.9%.When ACF was modified by Zn(CH_(3)COO)_(2),the adsorption capacity of ACF was enhanced,the heterojunction of TCN and TiO_(2) was formed,and the recombination rate of electron-hole was reduced.Thus,the adsorption-coupling photocatalytic efficiency of the composite photocatalyst could be improved.