The effect of defect emissions on enhancement photocatalytic performance of ZnSe QDs and ZnSe/rGO nanocomposites
A systematic study about the origin of defects emission of ZnSe structure was conducted by photoluminescence (PL) spectrometer at room temperature. It was observed that different intermediate energy levels in band-gap space of ZnSe structure were generated by different defects such as Se-, Zn-vacanc...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Published: |
Elsevier
2018
|
| Subjects: |
| _version_ | 1825721460005535744 |
|---|---|
| author | Yousefi, Ramin Azimi, Hassan Rayat Mahmoudian, Mohammad Reza Basirun, Wan Jefrey |
| author_facet | Yousefi, Ramin Azimi, Hassan Rayat Mahmoudian, Mohammad Reza Basirun, Wan Jefrey |
| author_sort | Yousefi, Ramin |
| collection | UM |
| description | A systematic study about the origin of defects emission of ZnSe structure was conducted by photoluminescence (PL) spectrometer at room temperature. It was observed that different intermediate energy levels in band-gap space of ZnSe structure were generated by different defects such as Se-, Zn-vacancies, Se-, Zn-interstitials, and surface states. Effects of these defects on the photocatalytic performance of ZnSe quantum dots (QDs) and ZnSe/graphene nanocomposites were investigated. The pristine ZnSe QDs and ZnSe/graphene nanocomposites were synthesized by a co-precipitation method. The PL spectra of the samples showed four emissions from four regions of the visible spectrum such as violet, green, orange, and red emissions. The violet emission was associated with the near-band-edge (NBE) of the ZnSe nanostructures, while, the other emissions were related to different defects of ZnSe structures. Annealing the samples in the H2 atmosphere caused to increase orange emission intensity and indicated that origin of orange emission was a donor-acceptor pair (DAPs) related to singly positively charged Se-vacancies (VSe) to singly negatively charged zinc vacancy (VZn −). Photocatalytic study of the samples to remove the methylene blue (MB) dye showed that the photocatalytic performance of the samples improved by graphene as an additive and increasing the orange emission intensity. |
| first_indexed | 2024-03-06T05:50:39Z |
| format | Article |
| id | um.eprints-20248 |
| institution | Universiti Malaya |
| last_indexed | 2024-03-06T05:50:39Z |
| publishDate | 2018 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | um.eprints-202482019-01-30T07:29:53Z http://eprints.um.edu.my/20248/ The effect of defect emissions on enhancement photocatalytic performance of ZnSe QDs and ZnSe/rGO nanocomposites Yousefi, Ramin Azimi, Hassan Rayat Mahmoudian, Mohammad Reza Basirun, Wan Jefrey Q Science (General) QD Chemistry A systematic study about the origin of defects emission of ZnSe structure was conducted by photoluminescence (PL) spectrometer at room temperature. It was observed that different intermediate energy levels in band-gap space of ZnSe structure were generated by different defects such as Se-, Zn-vacancies, Se-, Zn-interstitials, and surface states. Effects of these defects on the photocatalytic performance of ZnSe quantum dots (QDs) and ZnSe/graphene nanocomposites were investigated. The pristine ZnSe QDs and ZnSe/graphene nanocomposites were synthesized by a co-precipitation method. The PL spectra of the samples showed four emissions from four regions of the visible spectrum such as violet, green, orange, and red emissions. The violet emission was associated with the near-band-edge (NBE) of the ZnSe nanostructures, while, the other emissions were related to different defects of ZnSe structures. Annealing the samples in the H2 atmosphere caused to increase orange emission intensity and indicated that origin of orange emission was a donor-acceptor pair (DAPs) related to singly positively charged Se-vacancies (VSe) to singly negatively charged zinc vacancy (VZn −). Photocatalytic study of the samples to remove the methylene blue (MB) dye showed that the photocatalytic performance of the samples improved by graphene as an additive and increasing the orange emission intensity. Elsevier 2018 Article PeerReviewed Yousefi, Ramin and Azimi, Hassan Rayat and Mahmoudian, Mohammad Reza and Basirun, Wan Jefrey (2018) The effect of defect emissions on enhancement photocatalytic performance of ZnSe QDs and ZnSe/rGO nanocomposites. Applied Surface Science, 435. pp. 886-893. ISSN 0169-4332, DOI https://doi.org/10.1016/j.apsusc.2017.11.183 <https://doi.org/10.1016/j.apsusc.2017.11.183>. https://doi.org/10.1016/j.apsusc.2017.11.183 doi:10.1016/j.apsusc.2017.11.183 |
| spellingShingle | Q Science (General) QD Chemistry Yousefi, Ramin Azimi, Hassan Rayat Mahmoudian, Mohammad Reza Basirun, Wan Jefrey The effect of defect emissions on enhancement photocatalytic performance of ZnSe QDs and ZnSe/rGO nanocomposites |
| title | The effect of defect emissions on enhancement photocatalytic performance of ZnSe QDs and ZnSe/rGO nanocomposites |
| title_full | The effect of defect emissions on enhancement photocatalytic performance of ZnSe QDs and ZnSe/rGO nanocomposites |
| title_fullStr | The effect of defect emissions on enhancement photocatalytic performance of ZnSe QDs and ZnSe/rGO nanocomposites |
| title_full_unstemmed | The effect of defect emissions on enhancement photocatalytic performance of ZnSe QDs and ZnSe/rGO nanocomposites |
| title_short | The effect of defect emissions on enhancement photocatalytic performance of ZnSe QDs and ZnSe/rGO nanocomposites |
| title_sort | effect of defect emissions on enhancement photocatalytic performance of znse qds and znse rgo nanocomposites |
| topic | Q Science (General) QD Chemistry |
| work_keys_str_mv | AT yousefiramin theeffectofdefectemissionsonenhancementphotocatalyticperformanceofznseqdsandznsergonanocomposites AT azimihassanrayat theeffectofdefectemissionsonenhancementphotocatalyticperformanceofznseqdsandznsergonanocomposites AT mahmoudianmohammadreza theeffectofdefectemissionsonenhancementphotocatalyticperformanceofznseqdsandznsergonanocomposites AT basirunwanjefrey theeffectofdefectemissionsonenhancementphotocatalyticperformanceofznseqdsandznsergonanocomposites AT yousefiramin effectofdefectemissionsonenhancementphotocatalyticperformanceofznseqdsandznsergonanocomposites AT azimihassanrayat effectofdefectemissionsonenhancementphotocatalyticperformanceofznseqdsandznsergonanocomposites AT mahmoudianmohammadreza effectofdefectemissionsonenhancementphotocatalyticperformanceofznseqdsandznsergonanocomposites AT basirunwanjefrey effectofdefectemissionsonenhancementphotocatalyticperformanceofznseqdsandznsergonanocomposites |