Light-Activated Sub-ppm NO2 Detection by Hybrid ZnO/QD Nanomaterials vs. Charge Localization in Core-Shell QD

Artem Chizhov, Roman Vasiliev, Marina Rumyantseva, Ivan Krylov, Konstantin Drozdov, Maria Batuk, Joke Hadermann, Artem Abakumov, Alexander Gaskov

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

New hybrid materials—photosensitized nanocomposites containing nanocrystal heterostructures with spatial charge separation, show high response for practically important sub-ppm level NO2 detection at room temperature. Nanocomposites ZnO/CdSe, ZnO/(CdS@CdSe), and ZnO/(ZnSe@CdS) were obtained by the immobilization of nanocrystals—colloidal quantum dots (QDs), on the matrix of nanocrystalline ZnO. The formation of crystalline core-shell structure of QDs was confirmed by HAADF-STEM coupled with EELS mapping. Optical properties of photosensitizers have been investigated by optical absorption and luminescence spectroscopy combined with spectral dependences of photoconductivity, which proved different charge localization regimes. Photoelectrical and gas sensor properties of nanocomposites have been studied at room temperature under green light (λmax = 535 nm) illumination in the presence of 0.12–2 ppm NO2 in air. It has been demonstrated that sensitization with type II heterostructure ZnSe@CdS with staggered gap provides the rapid growth of effective photoresponse with the increase in the NO2 concentration in air and the highest sensor sensitivity toward NO2. We believe that the use of core-shell QDs with spatial charge separation opens new possibilities in the development of light-activated gas sensors working without thermal heating.

Original languageEnglish
Article number231
JournalFrontiers in Materials
Volume6
DOIs
Publication statusPublished - 24 Sep 2019
Externally publishedYes

Keywords

  • CdSe quantum dots
  • charge spatial localization
  • core/shell heterostructures
  • room temperature semiconductor gas sensor
  • sub-ppm NO detection
  • visible light activation

Fingerprint

Dive into the research topics of 'Light-Activated Sub-ppm NO2 Detection by Hybrid ZnO/QD Nanomaterials vs. Charge Localization in Core-Shell QD'. Together they form a unique fingerprint.

Cite this