CsPbBr_(3)纳米晶的水相阴极电化学发光机理  

Cathodic electrochemiluminescence behavior related of CsPbBr_(3) NCs in aqueous phase

作　　者：李萌萌 李哲 黄媛 申大忠[1] Li Meng-meng;Li Zhe;Huang Yuan;Shen Da-zhong(College of Chemistry,Chemical Engineering and Materials Science,ShandongNormal University,Jinan 250014,China)

机构地区：[1]山东师范大学化学化工与材料科学学院,山东济南250014

出　　处：《化学传感器》2021年第1期32-38,共7页Chemical Sensors

基　　金：国家自然科学基金资助项目(21874083)。

摘　　要：使用(NH_(4))_(2)S_(2)O_(8)作为共反应剂,以CsPbBr_(3)纳米晶(NCs)修饰的玻碳电极(GCE)上可产生增强的阴极电化学发光(ECL)信号,相对于未修饰的GCE,阴极ECL信号增强4.1倍,且在连续的电化学激发过程中,ECL强度随着电位扫描圈数的增加进一步增强,至4圈后趋于稳定值,其值相对于起始值增强2.6倍。而GCE|CsPbBr_(3) NCs的阳极ECL强度,却随电位扫描圈数的增多快速衰减,4圈之后已无ECL信号。但使用已无阳极ECL的GCE|CsPbBr_(3) NCs仍可激发出增强的阴极ECL信号。此外,用已分解无荧光的CsPbBr_(3)残渣修饰GCE,也能测量到增强的阴极ECL信号,其强度也随电位扫描圈数的增加而增强。由此推测,CsPbBr_(3) NCs在(NH_(4))_(2)S_(2)O_(8)存在下的阴极ECL增强作用,很可能来自CsPbBr_(3)或其分解产物对S_(2)O_(8)^(2-)本身的阴极ECL的增强,它们是S_(2)O_(8)^(2-)阴极ECL的共反应剂或者共反应促进剂,CsPbBr_(3) NCs本身并不是很强的阴极ECL发光体。In the presence of(NH_(4))_(2)S_(2)O_(8) as the co-reactant,moderate-intensity cathodic electrochemiluminescence(ECL)signal was measured on the glassy carbon electrode(GCE)modified by CsPbBr_(3) nanocrystals(NCs),enhancing 4.1 folds in compared with bare GCE.During the continuous cyclic voltammetric scanning,the cathodic ECL intensity is increased gradually and approached to stable level after 4 cycles(2.6 times of the initial intensity).But the anodic ECL of GCE|CsPbBr_(3) NCs is decayed rapidly during the continuous potential scanning cycles.Interestingly,a strong cathodic ECL signal was still measured in the GCE|CsPbBr_(3) NCs without anode ECL.In addition,the GCE modified with non-fluorescent CsPbBr_(3) residue was also generated strong cathodic ECL signal,and its intensity is increased withe increasing potential scanning cycles.Accordingly,it is speculated that the cathodic ECL behavior of GCE|CsPbBr_(3) NCs in the presence of(NH_(4))_(2)S_(2)O_(8) may be originated from the ECL of S_(2)O_(8)^(2-).CsPbBr_(3) NCs and/or its decomposition products are the co-reactant or promoter for the ECL of S_(2)O_(8)^(2-).Hence,CsPbBr_(3) NCs is not a strong luminophore for the cathodic ECL in GCE|CsPbBr_(3) NCs.

关 键 词：电化学发光 钙钛矿 发光机制 共反应促进剂 

分 类 号：TB383.1[一般工业技术—材料科学与工程] O646[理学—物理化学]