TY - JOUR

T1 - Insight into morphology dependent charge carrier dynamics in ZnSe-CdS nanoheterostructures

AU - Mittal, Mona

AU - Dana, Jayanta

AU - Lübkemann, Franziska

AU - Ghosh, Hirendra N.

AU - Bigall, Nadja C.

AU - Sapra, Sameer

N1 - Funding Information: MM and JD acknowledge the CSIR for the SRF fellowship. The project was partially funded by DST–SERB (grant no. EMR/2015/000005 and DST/TMD/CERI/C166(C)). The authors are also grateful for the financial support from the DAAD DST PPP Project ID 57212806 (INT/FRG/DAAD/P-07/2016). N. C. B. and F. L. acknowledge the funding from the German Federal Ministry of Education and Research (BMBF) within the framework of the program NanoMatFutur (support code 03×5525). The project leading to this application has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 714429).

PY - 2022/4/14

Y1 - 2022/4/14

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=85128192673&partnerID=8YFLogxK

U2 - 10.1039/d1cp05872j

DO - 10.1039/d1cp05872j

M3 - Article

C2 - 35348140

AN - SCOPUS:85128192673

VL - 24

SP - 8519

EP - 8528

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 14

ER -