(15d) Optimizing Nanoscale Catalyst/Semiconductor Photoelectrocatalysts with Interfacial Design

A promising system for high-efficiency photoelectrochemical water splitting consists of two series-connected semiconductors each coupled with nanoparticle electrocatalysts to perform the hydrogen evolution and oxygen evolution half-reactions.¹ It has been established that the interface between the semiconductor and electrocatalysts plays a pivotal role in the efficiency of these systems.² In this contribution, we perform rigorous electrochemical experiments, interfacial atomistic characterization, and computational modeling to study the interface of a functioning semiconductor (silicon) and nickel electrocatalysts in photoelectrochemical water splitting. We found that the interface is highly dynamic under operating conditions and that the evolution of the interface plays a critical role in (1) minimizing the electron/hole recombination by influencing the charge carrier fluxes, (2) increasing the barrier height of the junction, and (3) improving the stability of the system.³ Overall, these findings are important for fundamentally understanding and optimizing nanoparticle catalyst/semiconductor interfaces which are ubiquitous in photoelectrocatalysts.

References:

[1] Seitz, L. C.; Chen, Z.; Forman, A. J.; Pinaud, B. A.; Benck, J. D.; Jaramillo, T. F. ChemSusChem 2014

[2] Quinn, J.; Hemmerling, J.; Linic, S. ACS Energy Lett. 2019

[3] Hemmerling, J.; Quinn, J.; Linic, S. Adv. Energy Mater. 2020