Understanding the Role of Copper Vacancies in Photoelectrochemical CO2 Reduction on Cuprous Oxide

• Published in: The journal of physical chemistry letters 2022-04, Vol.13 (16), p.3667-3673
• Main Authors: Sequeda, Ingrid N, Meléndez, Angel M
• Format: Article
• Language: English
• Subjects: Physical Insights into Chemistry, Catalysis, and Interfaces
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.2c00751

Controlling the electronic and photoexcited properties of cuprous oxide (Cu2O) through slight modifications of the synthesis method can impact a wide range of emerging technologies. Herein, we consider copper vacancies in Cu2O as a prototype of a p-type oxide semiconductor for studying the impact of crystal and electronic structure on carbon dioxide photoreduction. Oriented films of copper vacancy modulated Cu2O consisting of nano twin structures are electrodeposited by changing the potential in an aqueous alkaline copper­(II)-lactate solution. The copper vacancies introduce tail states inside the band gap, improving the hole concentration and facilitating the charge separation and transfer in the Cu2O photocathode. This study gives an in-depth view of how a cation-deficient structure regulates and promotes photoelectrochemical activity toward CO2 reduction.