g-C_(3)N_(4)/TiO_(2)-PVDF光响应膜界面实现高效油水分离:不同暴露晶面诱导的渗透性和选择性差异及性能  

Efficient Oil-water Separation at the g-C_(3)N_(4)/TiO_(2)-PVDF Photoresponsive Membrane Interface:Permeability and Selectivity Differences Induced by Different Exposed Crystal Planes and Performance

作　　者：祖鹏 袁鹏程 王曙光[2] 孙雪菲 ZU Peng;YUAN Pengcheng;WANG Shuguang;SUN Xuefei(School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009,China;School of Environmental Science and Engineering,Shandong University,Qingdao 266237,China)

机构地区：[1]合肥工业大学资源与环境工程学院,合肥230009 [2]山东大学环境科学与工程学院,青岛266237

出　　处：《高等学校化学学报》2023年第6期121-130,共10页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:51978227)资助.

摘　　要：油滴堵塞导致的膜污染问题限制了膜技术在油水分离中的应用,构建选择性分离油水混合液的功能界面是实现高效油水分离的重要途径.本文制备了TiO_(2)(001)和(101)晶面暴露的g-C_(3)N_(4)/TiO_(2)-PVDF(聚偏氟乙烯膜)光催化膜,研究了不同暴露晶面对油水分离效果的影响及作用过程.结果显示,光照射下,TiO_(2)(001)晶面赋予了g-C_(3)N_(4)/TiO_(2)(001)-PVDF膜优异的超亲水和水下超疏油特性,与TiO_(2)(101)晶面暴露的膜相比,g-C_(3)N_(4)/TiO_(2)(001)-PVDF膜具有更优异的油水分离性能.g-C_(3)N_(4)/TiO_(2)(001)PVDF膜在可见光照射下,纯水通量达到2002.9 L·m^(-2)·h^(-1),较g-C_(3)N_(4)/TiO_(2)(101)-PVDF膜提升了60.8%,较黑暗条件下提升了47.1%;对5种不同油类物质的截留效率均>99%,且保持420.4~665.2 L·m^(-2)·h^(-1)的高渗透通量.而g-C_(3)N_(4)/TiO_(2)(101)-PVDF膜截留效率最高仅有61.8%,且渗透通量不足200 L·m^(-2)·h^(-1).通过瞬态光电流响应和电子顺磁共振技术探究了不同晶面暴露光催化膜的作用机理.结果表明,g-C_(3)N_(4)/TiO_(2)(001)-PVDF膜的光响应电流更强且羟基自由基产量更多.g-C_(3)N_(4)/TiO_(2)(001)-PVDF膜经过长达360 min的连续实验,渗透通量依然有264 L·m^(-2)·h^(-1);8次循环再生实验中始终保持高截留效率和渗透通量.Membrane technology is constrained by membrane fouling of oil droplet obstruction in oil-water separation.A crucial step toward effective oil-water separation is the construction of a functional interface for selective separation of the oil-water mixture.In this paper,g-C_(3)N_(4)/TiO_(2)-PVDF(polyvinglidene fluoride)photocatalytic membranes with different exposed crystal planes of TiO_(2)were prepared,and the effects of different exposed crystal planes on oil-water separation were studied.The experimental results show that the TiO_(2)(001)surface endows the g-C_(3)N_(4)/TiO_(2)(001)-PVDF membrane with excellent superhydrophilicity and underwater superoleophobicsuperoil transport properties under sunlight irradiation,and compared with the TiO_(2)(101)surface exposed membrane,g-C_(3)N_(4)/TiO_(2)(001)-PVDF membrane has better oil-water separation performance.Under visible light,the pure water flux of g-C_(3)N_(4)/TiO_(2)(001)-PVDF membrane reaches 2002.9 L·m^(-2)·h^(-1),which is 60.8%higher than that of g-C_(3)N_(4)/TiO_(2)(101)-PVDF membrane,and 47.1%higher than that under dark conditions.Simultaneously,the rejection efficiency of the five kinds of oil substances is more than 99%,and the high permeation flux of 420.4—665.2 L·m^(-2)·h^(-1)is maintained.The highest rejection efficiency of g-C_(3)N_(4)/TiO_(2)(101)-PVDF membrane is only 61.8%,and the permeation flux is less than 200 L·m^(-2)·h^(-1).The mechanism of different crystal planes was explored by transient photocurrent response and electron paramagnetic resonance technology.The results showed that the g-C_(3)N_(4)/TiO_(2)(001)-PVDF membrane had a stronger light response current and more hydroxyl radical production.The permeation flux of g-C_(3)N_(4)/TiO_(2)(001)-PVDF membrane was still 264 L·m^(-2)·h^(-1)after a 360 min continuous experiment.High rejection efficiency and permeation flux were always maintained in the 8 cycles of regeneration experiments.Obviously,the photocatalytic membrane with exposed TiO_(2)(001)has a greater permeability,select

关 键 词：油水分离 光诱导转化 g-C_(3)N_(4)/TiO_(2) 晶面暴露 

分 类 号：O643[理学—物理化学]