B掺杂对负载型TiO_2光催化剂脱硝性能的影响

采用超声辅助溶胶-凝胶法制备活化半焦负载B掺杂TiO_2光催化剂,即B-TiO_2/ASC。在相同实验条件下,分别在紫外和可见光下研究其对模拟烟气的光催化氧化脱硝性能。结果表明,在紫外和可见光下,B掺杂光催化剂的活性得到提高,在可见光下的活性增加更加显著,反应180 min后仍可保持80%以上的脱硝率。结合XRD和FT-IR分析,可以看出B以取代掺杂的方式存在于TiO_2中并且导致TiO_2表面缺陷。表面缺陷有助于光生载流子的分离,从而延长光生电子的寿命并增加参与光催化反应的光生电子数量,从而产生更多的羟基自由基氧化NO,最终提高光催化脱硝率。

Effect of B doping on DeNOx performance of supported TiO2 photocatalyst

B-doped TiO₂ photocatalyst supported on activated semi-coke,namely B-TiO₂/ASC,was prepared by ultrasonic-assisted sol-gel method.Under the same experimental conditions,photocatalytic activities for NO removal was studied under UV and visible light irradiation, respectively.The results showed that under UV and visible light irradiation,activity of B-doped catalysts was improved,activity under visible light irradiation increased more significantly, and NO removal efficiency could still maintained over 80% after 180 min reaction.X-ray diffraction and FT-IR spectra results indicated that B got into TiO₂ lattice by substitution doping and caused TiO₂ surface defects.Surface defects contributed to the separation of photogenerated carriers,thereby prolonged the lifetime of photo-generated electrons and increased the number of photo-generated electrons involved in photocatalytic reactions,generated more hydroxyl radicals to oxidize NO,and ultimately increased photocatalytic denitration efficiency.