Article Title

Correlation between types of defects/vacancies of Bi₂S₃ nanostructures and their transient photocurrent

Authors

Mingyang Liu, Department of Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA
Luqing Wang, Department of Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA
Pei Dong, Department of Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA
Liangliang Dong, Department of Chemistry, Rice University, Houston, TX 77005, USA
Xifan Wang, Department of Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA
Jarin Joyner, Department of Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA
Xiangjian Wan, College of Chemistry, Nankai University, Tianjin 300071, China
Boris I. Yakobson, Department of Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA
Robert Vajtai, Department of Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA
Pulickel Ajayan, Department of Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA
Pol Spanos, Department of Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA

Keywords

Bi2S3 microspheres, nanorod assembly, defects/vacancies, positron annihilation spectrometry, transient photocurrent

Abstract

ABSTRACT Crystalline nanostructures possess defects/vacancies that affect their physical and chemical properties. In this regard, the electronic structure of materials can be effectively regulated through defect engineering; therefore, the correlation between defects/vacancies and the properties of a material has attracted extensive attention. Here, we report the synthesis of Bi2S3 microspheres by nanorod assemblies with exposed {211} facets, and the investigation of the types and concentrations of defects/vacancies by means of positron annihilation spectrometry. Our studies revealed that an increase in the calcined temperature, from 350 to 400 °C, led the predominant defect/vacancy densities to change from isolated bismuth vacancies (VBi) to septuple Bi3+–sulfur vacancy associates (VBiBiBiSSSS). Furthermore, the concentration of septuple Bi3+–sulfur vacancy associates increased as the calcined temperature was increased from 400 to 450 °C. The characterized transient photocurrent spectrum demonstrates that the photocurrent values closely correlate with the types and concentrations of the predominant defects/vacancies. Our theoretical computation, through first principles, showed that VBiBiBiSSSS strongly absorbs I (sol) 2 , easily desorbs I (sol)  , and enhances the electrocatalytic activity of the nanostructures.

Graphical Abstract

DOI

https://doi.org/10.1007/s12274-017-1440-7

Publisher

Tsinghua University Press

Recommended Citation

Mingyang Liu,Luqing Wang,Pei Dong,Liangliang Dong,Xifan Wang,Jarin Joyner,Xiangjian Wan,Boris I. Yakobson,Robert Vajtai,Pulickel Ajayan,Pol Spanos, Correlation between types of defects/vacancies of Bi2S3 nanostructures and their transient photocurrent. NanoRes.2017, 10(7): 2405–2414