CAJ | 학술논문

用X射线衍射、透射电镜、紫外-可见光漫反射光谱等表征手段研究了纳米TiO2/C光催化剂的晶体结构和性能.结果表明:碳黑改性促使TiO2在较低温度(＜500 ℃)发生由锐钛矿相向金红石相转变,并有效抑制了纳米TiO2晶粒长大,经400 ℃热处理后,TiO2晶粒尺寸为7.3 nm.由于纳米碳黑弥散分布于纳米TiO2颗粒中,提高了该催化剂对亚甲基蓝分子的吸附性能.通过碳黑粒子的光敏化作用提高纳米TiO2的可见光光催化性能,加入5%(质量分数)纳米碳黑的TiO2/C光催化剂在400 ℃热处理后对亚甲基蓝降解率可达到93%.过多的碳黑会因其阻碍纳米TiO2与有机物接触而降低其降解效果,而过少的碳黑则会降低纳米碳黑对催化剂的敏化作用而降低其催化活性.
용X사선연사、투사전경、자외-가견광만반사광보등표정수단연구료납미TiO2/C광최화제적정체결구화성능.결과표명:탄흑개성촉사TiO2재교저온도(＜500 ℃)발생유예태광상향금홍석상전변,병유효억제료납미TiO2정립장대,경400 ℃열처리후,TiO2정립척촌위7.3 nm.유우납미탄흑미산분포우납미TiO2과립중,제고료해최화제대아갑기람분자적흡부성능.통과탄흑입자적광민화작용제고납미TiO2적가견광광최화성능,가입5%(질량분수)납미탄흑적TiO2/C광최화제재400 ℃열처리후대아갑기람강해솔가체도93%.과다적탄흑회인기조애납미TiO2여유궤물접촉이강저기강해효과,이과소적탄흑칙회강저납미탄흑대최화제적민화작용이강저기최화활성.
Nano-TiO2/C composites were prepared and characterized by X-ray diffraction, transmission electron microscopy and ultraviolet-visible light diffusion reflectance spectroscopy. The results show that nano-carbon black (NCB) improved the transformation of TiO2 from anatase to rutile at the low temperature (＜500 ℃) and restrained the growth of TiO2 crystals. Nano-TiO2 crystals of about 7.3 nm were obtained after heat treated at 400 ℃. NCB particles was dispersed on the TiO2particles and improved the adsorption property on methylene blue of the catalysts. The visible light photocatalytic activity of the catalysts was promoted by the photo-sensitization of NCB. The degradation rate of methylene blue reaches 93% as the nano-TiO2 modificated with 5% (in mass)NCB treated at the 400 ℃ for 4 h. However, more NCB decreased the catalytic activity due to the lower contact probability between the nano-TiO2 particles and methylene blue molecules. On the contrary, the insufficient NCB adding also decreased the catalytic activity of the catalysts for the lower photo-sensitization.