首页 | 本学科首页   官方微博 | 高级检索  
     检索      

Ag2S2O7/Ag2O纳米颗粒异质结构的制备及其太阳光全光谱光催化降解应用
引用本文:李海东,陈廷翰,王瑶,唐建国,王亚娜,桑元华,刘宏.Ag2S2O7/Ag2O纳米颗粒异质结构的制备及其太阳光全光谱光催化降解应用[J].催化学报,2017,38(6).
作者姓名:李海东  陈廷翰  王瑶  唐建国  王亚娜  桑元华  刘宏
作者单位:1. 青岛大学杂化材料研究院,山东青岛,266071;2. 清华大学附属中学1506班级,北京,100084;3. 山东大学晶体材料国家重点实验室,山东济南,250100
基金项目:b06015).国家自然科学基金,创新研究群体,高等学校学科创新引智计划
摘    要:Ag2O是优良的感光材料,很少作为光催化材料,而常被用作光催化材料的共催化剂.此外,由于Ag2O禁带宽度窄,且可有效吸收近红外光,因而不能用于全太阳光谱的光催化应用中.同时很少被用作NIR催化剂.本文中不仅研究了纳米Ag2O颗粒的UV-Vis光催化性能,而且还系统探究了其NIR光催化活性.由于在紫外线和可见光的照射下,Ag2O纳米颗粒易发生光还原失活,因而对Ag2O表面硫化处理,使其表面上生长Ag2S2O7层以形成Ag2S2O7/Ag2O异质结,探究了该异质结UV-Vis光催化活性及其光催化循环稳定性;同时,考察了其近红外光催化及其重复使用性能.利用沉淀法成功制备了Ag2O纳米颗粒,并通过在其表面部分硫化处理得到Ag2S2O7,成功构筑Ag2S2O7/Ag2O异质结构,并研究了该Ag2S2O7/Ag2O异质结构UV-Vis-NIR光催化降解有机污染物性能.研究表明,Ag2O纳米颗粒在光子能量较低的NIR照射条件下具有较强的光催化活性,但UV-Vis照射下,虽然Ag2O具有光催化活性,但易发生光还原生成单质银,降低其光催化稳定性;Ag2S2O7/Ag2O纳米异质结,虽然在UV-Vis-NIR范围内光催化活性略降于Ag2O,但稳定性显著提高,总体来看,Ag2S2O7/Ag2O异质结构在全光谱催化方面更具优势.这主要是由于Ag2O表面部分硫化得到的Ag2S2O7纳米颗粒,且二者之间能带匹配促进了光生载流子分离,同时Ag2O表面的Ag2S2O7颗粒直接吸收能量较高的UV-Vis,进而保护内部Ag2O,抑制了其自身还原,可显著提高Ag2S2O7/Ag2O异质结在UV-Vis-NIR催化活性及稳定性.实验结果分析表明,Ag2S2O7/Ag2O异质结纳米颗粒在UV-Vis-NIR条件下均具有稳定且高效的光催化活性,其主要原因为:(1)具有窄带隙的Ag2O可有效拓宽该异质结的光谱吸收;(2)Ag2S2O7/Ag2O异质结能带匹配可有效促使光生载流子分离;(3)Ag2O颗粒表面的Ag2S2O7纳米颗粒可有效提高Ag2S2O7/Ag2O异质结纳米颗粒的光化学稳定性,尤其是在UV-Vis条件下的化学稳定性.Ag2O纳米颗粒受到光照(UV-Vis-NIR)激发后产生电子-空穴对,由于Ag2S2O7与Ag2O能带位置的匹配,Ag2O导带的光生电子注入Ag2S2O7的导带;而Ag2S2O7价带的光生空穴注入Ag2O的价带.Ag2O表面的Ag2S2O7颗粒可有效捕捉电子,从而阻止Ag2O产生的电子-空穴对复合,进而提高光催化活性;同时当光子能量较高(UV以及部分短波长的Vis)时,Ag2O表面的Ag2S2O7颗粒直接吸收该部分光能,进而保护内部Ag2O发生自身还原,因此,Ag2S2O7/Ag2O异质结纳米颗粒在UV,Vis及NIR条件下均具有稳定且高效的光催化活性,在高效利用全光谱光催化降解有机污染物方面具有较大的潜力.

关 键 词:全光谱太阳光  Ag2O纳米颗粒  Ag2O/Ag2S2O7  异质结  光催化

Surface-sulfurized Ag2O nanoparticles with stable full-solar-spectrum photocatalytic activity
Haidong Li,Tinghan Chen,Yao Wang,Jianguo Tang,Yana Wang,Yuanhua Sang,Hong Liu.Surface-sulfurized Ag2O nanoparticles with stable full-solar-spectrum photocatalytic activity[J].Chinese Journal of Catalysis,2017,38(6).
Authors:Haidong Li  Tinghan Chen  Yao Wang  Jianguo Tang  Yana Wang  Yuanhua Sang  Hong Liu
Abstract:Ag2O has attracted much recent attention, because of its high photocatalytic activity in the ultravio-let (UV)-visible region. However, there have been few reports on the near-infrared (NIR) photo-catalytic activity of Ag2O. This paper reports the high NIR photocatalytic activity of Ag2O nanoparti-cles. Ag2O is unsuitable for application in full-solar-spectrum photocatalysis, because it is unstable under UV irradiation. A surface sulfurization process was carried out to address this issue. Specifi-cally, a layer of Ag2S2O7 nanoparticles was grown on the surface of the Ag2O nanoparticles, to im-prove the stability of the Ag2O photocatalyst and enhance its photocatalytic activity in the UV, visible and NIR regions. The Ag2O/Ag2S2O7 heterostructure is a stable and efficient full-solar-spectrum photocatalyst. It has potential application in the photodegradation of organic pollutants, and more generally in environmental engineering where full utilization of the solar spectrum is required.
Keywords:Full-solar-spectrum  Silver oxide nanoparticles  Ag2O/Ag2S2O7  Heterostructure  Photocatalysis
本文献已被 万方数据 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号