The oxidation of water with sunlight provides the electrons and protons required for the generation of solar fuels. However, practical water photo-oxidation remains a significant scientific challenge. The Center for Hybrid Approaches in Solar Energy to Liquid Fuels (CHASE) has sought to develop hybrid photoelectrodes that integrate molecular catalysts with light absorbing semiconductors for efficient photoelectrochemical water oxidation. In this presentation, molecular water oxidation catalysts have been integrated with silicon light absorbers in semiconductor-insulator-conductor architectures. In these hybrid electrodes, the silicon light absorber is protected by an insulating oxide and a transparent conductive oxide overlayer to which molecular catalysts have been attached. These hybrid photoelectrodes provide photovoltages of &gt; 250 mV and sustained catalytic currents for water oxidation with Faradaic efficiencies for oxygen production of &gt; 60%. The photocurrent magnitude has been directly correlated with the structure of the molecular catalyst while mechanistic and theoretical studies have provided insights into key proton-coupled electron transfer steps that comprise the catalytic cycle. The impact of these findings on practical water oxidation with hybrid photoelectrodes will be discussed.

Hybrid photoelectrodes for water oxidation with molecular catalysts

ACS Spring 2022

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