Femtosecond transient absorption spectroscopy investigation into the electron transfer mechanism in photocatalysis

Abstract

Femtosecond transient absorption spectroscopy (fs-TAS) is a powerful technique for monitoring electron transfer kinetics in photocatalysis. Several important works have successfully elucidated the electron transfer mechanism in heterojunction photocatalysts (HPs)...

Deciphering ligand-controlled charge transfer from a metal–organic framework to cadmium sulfide for enhanced photocatalytic hydrogen evolution reaction

“…A similar situation was also reported for Pt/CdS, where the trapped state is formed and reduced in the charge recombination process. 75…”

“…A similar situation was also reported for Pt/CdS, where the trapped state is formed and reduced in the charge recombination process. 75 Further, we have carried out the TA studies for PBA-CdS. In contrast to NP-CdS-2, where an intermediate state was observed, the evolution of the long-lived state directly from the excited state was detected for PBA-CdS without the formation of a new intermediate state.…”

Highly Selective Photoconversion of CO2 to CH4 over SnO2/Cs3Bi2Br9 Heterojunctions Assisted by S-Scheme Charge Separation

“…In an inert Ar QDs are contributed by photoelectrons. 60 The normalized recovery kinetics at 485 and 550 nm within 100 ps are fitted for pure SnO 2 , Cs 3 Bi 2 Br 9 QDs, and SC4, corresponding to the dynamics of photoelectrons in the CB of SnO 2 and Cs 3 Bi 2 Br 9 , respectively (Figure 4g and h). Photogenerated electron relaxation in pure SnO 2 and Cs 3 Bi 2 Br 9 CBs occurs through two pathways: diffusion over lattices (Process 1, I) and recombination of charge carriers (Process 2, II).…”

S-Scheme Co9S8 Nanoflower/Red Phosphorus Nanosheet Heterojunctions for Enhanced Photocatalytic H2 Evolution

“…Recently, S-scheme heterojunction has received a lot of attention because it not only achieves effective spatial separation of charges but also maintains a robust redox capability. , In addition, its charge transfer process follows the thermodynamic law. Yu et al demonstrated the mechanism of the enhanced photocatalytic performance of the S-scheme heterojunction photocatalyst from the perspective of electron transfer kinetics by femtosecond transient absorption spectroscopy (fs-TAS). , The development of RP-based S-scheme heterojunction can address the drawback of the high charge recombination rate of RP, while keeping the strong redox ability of the original catalyst. For example, Jiang et al prepared α-Fe 2 O 3 /RP heterojunctions using a hydrothermal method; the 1.5% α-Fe 2 O 3 /RP composite had the highest H 2 (6.49 μmol·h –1 ·g –1 ) and O 2 (2.81 μmol·h –1 ·g –1 ) evolution rates, and the S-scheme charge transfer route promoted the charge separation between RP and α-Fe 2 O 3 effectively along with a strong redox ability .…”