Oxygen defects engineered CdS/Bi2O2.33 direct Z-Scheme heterojunction for highly sensitive photoelectrochemical assay of Hg2+
Oxygen defects engineered CdS/Bi2O2.33 direct Z-Scheme heterojunction for highly sensitive photoelectrochemical assay of Hg2+
复制标题
氧缺陷工程 CdS/Bi2O2.33 直接 Z 型异质结用于 Hg2 的高灵敏度光电化学测定
DOI：
10.1016/j.talanta.2020.121090
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发表时间：
2020
期刊：
影响因子：
6.1
通讯作者：
Zhao Yanqiu
中科院分区：
文献类型：
--
作者：
Wu Shuo;Zhao Yan;Deng Xunxun;Yang Xinlan;Wang Xiuyun;Zhao Yanqiu
这项工作表明，CdS/Bi2O2.33直接Z-计划异质结的光电化学响应，通过原位沉积CdS纳米晶体上的缺陷工程Bi2O2.33，可以调制的氧缺陷浓度。适当的氧缺陷不仅增加了可见光吸收，提供活性反应位点，增强PEC活性，而且促进了载流子的分离。CdS/Bi 2 O2. 33直接Z型异质结的形成通过扩展可见光吸收和促进载流子的分离和输运进一步改善了这些特性，但避免了使用贵金属纳米颗粒作为电子转移介质，因此具有低成本和易于制备的技术。CdS/Bi2O2.33直接Z型结的光电流响应比含氧缺陷少的结有明显提高，可作为Hg 2+的光电化学分析平台。Hg 2+与CdS中S2−的特异性相互作用使CdS/Bi2O2.33的光电流响应显著猝灭，这是由于HgS的形成。汞离子浓度在10 - 11 ~ 10 - 6 μ g/mL范围内与光电流呈线性关系，检出限为3.2 μ g/mL。在尿液、河水和海水的真实的样品分析中实现了高精度和良好的再现性。氧缺陷工程与直接Z模式电子输运原理的结合为制备高性能光电化学材料提供了新的途径，并可进一步与生物识别策略相结合，实现对生物分子的超灵敏检测。
This work demonstrates that the photoelectrochemical response of the CdS/Bi2O2.33direct Z-scheme heterojunction, synthesized by in situ deposition of CdS nanocrystals on the defect engineered Bi2O2.33, can be modulated by oxygen defect concentration. The appropriate oxygen defects not only increase the visible light absorption, provide active reaction sites to enhance PEC activity, but also promote the separation of carriers. The formation of CdS/Bi2O2.33direct Z-scheme heterojunction further improves these properties by extending the visible light absorption and promoting separation and transport of carriers, but avoids the usage of noble metal nanoparticles as electron transfer mediators, thus has a low cost and easy fabrication technology. The CdS/Bi2O2.33direct Z-scheme junction shows significantly improved photocurrent response as compared with those containing less oxygen defects, and is applied as a photoelectrochemical assay platform for Hg2+. The specific interaction between Hg2+and the S2−in CdS significantly quenches the photocurrent response of the CdS/Bi2O2.33due to the formation of HgS. The photocurrent decrease is linear to the concentration of Hg2+in the range from 10−11to 10−6g/mL, with the limit of detection of 3.2 pg/mL. High accuracy and good reproducibility are realized in the real sample analysis of urine, river water, and sea water. The integration of oxygen defect engineering and direct Z-scheme electron transport principle provides a new avenue for fabricating high performance photoelectrochemical materials, which can be further combined with bio-recognition strategy for the ultrasensitive detection of biological molecules.