Interfacing transition metal dichalcogenides with carbon nan-odots for managing photoinduced energy and charge-transfer processes

Journal of the American Chemical Society 2018, 140 (41), pp 13488–13496

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Journal of the American Chemical Society

 

Exfoliated semiconducting MoS2 and WS2 were covalently functionalized with 1,2-dithiolane-modified carbon nanodots (CNDs). The newly synthesized CND-MoS2 and CND-WS2 hybrids were characterized by spectroscopic, thermal and elec-tron microscopy imaging methods. Based on electronic absorption and fluorescence emission spectroscopy, modulation of the optoelectronic properties of TMDs by interfacing with CNDs was accomplished. Electrochemical studies revealed facile oxidation of MoS2 over WS2 in the examined hybrids, suggesting it to be better electron donor. Excited state events, inves-tigated by femtosecond transient absorption spectroscopic studies, revealed ultrafast energy transfer from photoexcited CNDs to both MoS2 and WS2. Interestingly, upon MoS2 photoexcitation charge transfer from an exciton dissociation path of MoS2 to CNDs, within CND-MoS2, was observed. However, such …