Programmable Photocatalysis via Symmetry-Defined Periodic Potentials

TL;DR

This paper introduces symmetry-defined periodic potentials as a novel method to enhance photocatalysis in atomically thin semiconductors by spatially separating photoexcited charge carriers, demonstrated through moiré patterns in monolayer InSe.

Contribution

It proposes and experimentally demonstrates a new approach using moiré patterns to control charge separation without altering surface chemistry in 2D materials.

Findings

Moiré patterns induce miniband formation and band-gap renormalization in monolayer InSe.

Periodic potentials enable effective charge separation while minimally affecting surface adsorption.

Electrostatic modulation from moiré patterns can be transferred to the active layer, controlling carrier distribution.

Abstract

Photocatalysis in atomically thin semiconductors is often limited by rapid electron-hole recombination, making it difficult to translate favorable band structures into efficient chemical function. Here we propose symmetry-defined periodic potentials as a strategy for photocatalysis: instead of modifying the chemistry of the active layer, one engineers a long-wavelength electrostatic landscape that spatially separates photoexcited electrons and holes. Applied to monolayer InSe, we show that experimentally accessible moir\'e patterns, such as those generated by twisted hBN, produce miniband formation, band-gap renormalization, and robust carrier separation. Using commensurate BN/InSe local registries, we further show that the moir\'e control layer transfers a measurable electrostatic modulation to InSe, providing the microscopic link between continuum potential engineering and the local surface environment. The key result is that the periodic potential strongly reorganizes carrier distribution while only weakly perturbing adsorption trends, thereby identifying a practically useful regime in which charge separation can be engineered without demanding major changes to the underlying surface chemistry. These results position periodic potentials as a broadly applicable design principle for photocatalysis and other light-driven interfacial phenomena in two-dimensional materials.