摘要
TiO_(2)异相结主要通过高温方法制备,所制备材料的形貌和组成较难控制,尤其是在较低温度下一步制备一维TiO_(2)异相结仍具有一定的挑战性。采用简单、方便的一步水热法,在较低温度下(180℃)制备了一维纳米TiO_(2)异相结材料。X射线衍射(XRD)和高分辨透射电镜(HRTEM)分析表明,制备的材料以一维金红石相TiO_(2)纳米棒(长度:(400±50)nm,直径:(60±5)nm)为基本结构,粒径分布均匀的锐钛矿相TiO_(2)纳米粒子(直径:(9.5±0.5)nm)高密度、单分散地负载在纳米棒上。通过控制水热反应时间成功调控了异相结中锐钛矿相TiO_(2)的含量(20%~50%),进而实现了其光催化降解HCHO性能的调控。实验结果表明,当锐钛矿相TiO_(2)的含量为33%时(TiO_(2)-24,水热时间24 h制备的样品),异相结光催化剂表现出最佳的HCHO降解性能:在低光强LED灯(波长为365 nm,光强为12.26 mW·cm^(-2))照射下,浓度约为120 mg·L^(-1)的HCHO气体在25 min后的降解率达到了92%,实现了高效、快速地去除空气中的HCHO(矿化为CO_(2))。稳态荧光光谱和光电化学测试表明,与其他水热时间的样品相比,TiO_(2)-24具有更高效的光生电荷分离和传输效率。一维TiO_(2)异相结不仅有利于光生电荷的传输,而且对电荷的分离具有定向驱动作用,使其具有较高的光催化降解HCHO性能。
TiO_(2) heterophase junctions are mainly prepared by high-temperature method,and it is difficult to control the morphology and composition of the prepared materials.Especially,it is still challenging to prepare a one-dimensional TiO_(2) heterophase junction at a lower temperature.In this paper,a simple and convenient one-step hydrothermal method was developed prepared one-dimensional nano-TiO_(2) heterophase junctions at a relatively low temperature(180℃).X-ray diffraction(XRD)and high-resolution transmission electron microscopy(HRTEM)analyses show that the one-dimensional rutile TiO_(2) nanorods(length:(400±50)nm,diameter:(60±5)nm)are the basic structure of the prepared materials,and the anatase TiO_(2) nanoparticles with uniform size distribution(diameter:(9.5±0.5)nm)are loaded on the nanorods in a high-density,monodispersed form.By adjusting the hydrothermal time,the anatase TiO_(2) contents in the prepared materials could be controlled within the range of 20%-50%.The TiO_(2) heterophase junctions were successfully applied to the photocatalytic degradation of formaldehyde.When the content of anatase phase TiO_(2) was 33%(TiO_(2)-24,the hydrothermal time was 24 h),the TiO_(2) heterophase junction had the best formaldehyde degradation performance.After 25 min photocatalytic reaction,the 92%of formaldehyde(120 mg·L^(-1))was degraded into CO_(2) under a low-intensity LED lamp(wavelength:365 nm,light intensity:12.26 mW·cm^(-2)),confirming the efficient activity of the TiO_(2) heterophase junction.Steady-state fluorescence spectroscopy and photoelectrochemical tests showed that charge separation and transfer efficiencies on TiO_(2)-24 were much higher than those on other samples prepared at different hydrothermal times.The one-dimensional TiO_(2) heterophase junction not only is beneficial to the transfer of photogenerated charge but also can directionally drive the separation of the charges,which makes one-dimensional TiO_(2) heterophase photocatalyst has a higher formaldehyde degradation performance.
作者
查凤娟
刘庆
王建友
林雨寒
王传义
李英宣
ZHA Feng-Juan;LIU Qing;WANG Jian-You;LIN Yu-Han;WANG Chuan-Yi;LI Ying-Xuan(School of Environmental Science and Engineering,Shaanxi University of Science&Technology,Xi′an 710021,China.;Yulin Yushen Industrial Zone Energy Technology Development Co.,Ltd.,Yulin,Shaanxi 719302,China)
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2022年第3期510-518,共9页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.21972082)资助。
