ZnxCd1–xS quantum dot with enhanced photocatalytic H2-production performance  

锌镉硫量子点增强的光催化产氢活性

作　　者：Rongrong Gao Bei Cheng Jiajie Fan Jiaguo Yu Wingkei Ho 高荣荣;程蓓;范佳杰;余家国;Wingkei Ho(武汉理工大学材料复合新技术国家重点实验室,湖北武汉430070;郑州大学材料科学与工程学院,河南郑州450001;香港教育大学科学与环境学系,中国香港)

机构地区：[1]State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,Hubei,China [2]School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,Henan,China [3]Department of Science and Environmental Studies,The Education University of Hong Kong,Hong Kong,China

出　　处：《Chinese Journal of Catalysis》2021年第1期15-24,共10页催化学报（英文）

基　　金：国家重点研发计划(2018YFB1502001);国家自然科学基金(21871217,U1905215,51961135303,51932007,U1705251);武汉理工大学材料复合新技术国家重点实验室创新基金(2017-ZD-4).

摘　　要：H2 is an important energy carrier for replacing fossil fuel in the future due to its high energy density and environmental friendliness.As a sustainable H2-generation method,photocatalytic H2 production by water splitting has attracted much interest.Here,oil-soluble ZnxCd1-xS quantum dot(ZCS QD)with a uniform particle size distribution were prepared by a hot-injection method.However,no photocatalytic H2-production activity was observed for the oil-soluble ZCS QD due to its hydrophobicity.Thus,the oil-soluble ZCS QD was converted into a water-soluble ZCS QD by a ligand-exchange method.The water-soluble ZCS QD exhibited excellent photocatalytic H2-production performance in the presence of glycerin and Ni^2+,with an apparent quantum efficiency of 15.9%under irradiation of 420 nm light.Further,the photocatalytic H2-generation activity of the ZCS QD was~10.7 times higher than that of the ZnxCd1-xS relative samples prepared by the conventional co-precipitation method.This work will inspire the design and fabrication of other semiconductor QD photocatalysts because QD exhibits excellent separation efficiency for photogenerated electron-hole pairs due to its small crystallite size.光催化分解水产氢是利用太阳能解决当今能源危机和环境污染问题的理想策略.硫化镉光催化剂由于具有较窄的带隙、有效的光吸收能力、较负的导带位置和较强的还原能力等而受到广泛关注.然而,硫化镉光催化剂的光生电子-空穴复合速率高,导致其光催化活性比较低,因此在光催化领域的应用受到限制.为此,人们采取了很多方法来改善硫化镉光催化剂的光催化性能,例如加入助催化剂、构建异质结、表面修饰以及形成固溶体光催化剂等.合成固溶体光催化剂被认为是提高硫化镉光催化活性最具有发展前景的方法之一,固溶体光催化剂通过形成轨道杂化而表现出可控的带隙和带边位置.在固溶体光催化剂中,锌镉硫胶体量子点引起了很多关注.锌镉硫胶体量子点的颗粒尺寸较小,这就使得光生电子和空穴由催化剂内部转移到表面的距离较短,增大了载流子分离效率.另外,锌镉硫胶体量子点具有较负的导带位置、可调控的带隙、较好的水中分散性以及良好的光吸收等优点,因此锌镉硫胶体量子点从其他光催化剂中脱颖而出.本文分别采用热注法和传统共沉淀法制备了油溶性锌镉硫量子点和水溶性锌镉硫纳米颗粒.发现油溶性量子点亲水性能较差,几乎没有光催化活性,但油溶性量子点易通过配体交换过程转换成水溶性量子点,无机硫作为锌镉硫量子点的表面水溶性配体,可使量子点具有较好的亲水性.通过电化学测试、稳态荧光以及时间分辨荧光测试结果表明,相比于锌镉硫纳米颗粒,水溶性锌镉硫量子点具有更高的电子空穴分离效率.光催化产氢测试发现,在牺牲剂甘油存在的条件下,水溶性锌镉硫量子点的光催化产氢速率(1220μmol g^−1 h^−1)显著提高,约是锌镉硫纳米颗粒产氢速率的10倍.加入助催化剂Ni^2+后,锌镉硫量子点表现出最高的光催化产氢活性(2253μmol g^�

关 键 词：ZnxCd1-xS Solid-solution photocatalyst Photocatalytic H2 production Oil-soluble quantum dot Water-oil soluble quantum dot 

分 类 号：TQ116.2[化学工程—无机化工] O643.36[理学—物理化学] O644.1[理学—化学]