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Mittal M, Dana J, Lübkemann F, Ghosh HN, Bigall NC, Sapra S. Insight into morphology dependent charge carrier dynamics in ZnSe-CdS nanoheterostructures. Phys Chem Chem Phys 2022; 24:8519-8528. [PMID: 35348140 DOI: 10.1039/d1cp05872j] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Semiconductor nanoheterostructures (NHSs) are being increasingly used for the photocatalytic conversion of solar energy in which photo-induced charge separation is an essential step and hence it is necessary to understand the effect of various factors such as size, shape, and composition on the charge transfer dynamics. Ultrafast transient absorption spectroscopy is used to investigate the nature and dynamics of photo-induced charge transfer processes in ZnSe-CdS NHSs of different morphologies such as nanospheres (NSs), nanorods (NRs), and nanoplates (NPs). It demonstrates the fast separation of charge carriers and localization of both charges in adjacent semiconductors, resulting in the formation of a charge-separated (CS) state. The lifetime of the charge-separated state follows the order of NSs < NPs < NRs, emphasizing the effect of morphology on the enhancement of photo-induced charge separation and suppression of backward recombination. The separated charge carriers have been utilized in visible light driven hydrogen production and the hydrogen generation activity follows the same order as that for the lifetime of the CS state, underlining the role of charge separation efficiency. Therefore, the variation of the morphology of NHSs plays a significant role in their charge carrier dynamics and hence the photocatalytic hydrogen production activity.
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Affiliation(s)
- Mona Mittal
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. .,Deparment of Chemistry, University Institute of Science, Chandigarh University, Gharaun, Punjab 140413, India
| | - Jayanta Dana
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai - 400085, India
| | - Franziska Lübkemann
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, D-30167 Hannover, Germany
| | - Hirendra N Ghosh
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai - 400085, India.,Institute of Nano Science and Technology, Knowledge City, Sector - 81, Mohali, Punjab 140306, India
| | - Nadja C Bigall
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, D-30167 Hannover, Germany
| | - Sameer Sapra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
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