Discovery of better photocatalytic materials maximizes product and energy yields, which are particularly important for processes like artificial photosynthesis and other renewable energy sources to become more efficient and reliable. Understanding the underlying charge transfer dynamics in photocatalytic materials aids in the design of even more efficient photocatalytic materials, leading to more green energy solutions. Two-dimensional (2D) materials encapsulated in the silicate clay Laponsite-RD (Lap) have been shown to be better photocatalysts than their nonencapsulated counterparts, and it has been theorized that holes transfer rapidly into Lap increasing the hole lifetime significantly, hence enhancing photocatalytic efficiency. However the exact mechanism has not been fully understood. This study examines the charge transfer in Lap-MoS2 and Lap-In2S3 to inform about the mechanisms at play. Raman spectroscopy and scanning electron microscopy (SEM) were employed to characterize particle size and uniformity. Solid-state high harmonic generation (sHHG) spectroscopy is used to probe the band structure of Lap-MoS2 and Lap-In2S3, and pump-probe sHHG allows measurement of electron-hole lifetimes which are compared to uncoated 2D semiconductor flakes. Uncovering the electron-hole dynamics and possible separation of these species is vital for the design of better photocatalysts as recombination has been a primary limiter in renewable energy efficiency.

Elucidating charge transfer dynamics in 2D clay-encapsulated materials for photocatalytic applications

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.