Will Cuprous Oxide Really Make It in Water-Splitting Applications?

For cost-effective solar hydrogen production on an industrial scale, Earth-abundant, low-cost, and easily processable materials are required. In this Perspective, a case is made that cuprous oxide has strong potential for practical large-scale water splitting. Recent research directions for improved efficiency and durability are highlighted, which target both the back and front interfaces of the Cu2O light absorber as well as protective overlayers and co-catalysts. The translation of high-efficiency thin-film device architectures to photocatalytic sheets or particles is proposed as a disruptive approach to solar hydrogen generation with fertile ground for new scientific discoveries.

Automated summary

In order to achieve cost-effective solar hydrogen production on a large scale, materials that are abundant, low-cost, and easily processed are necessary. This article argues that cuprous oxide shows strong potential for practical water splitting on a large scale, and emphasizes recent research directions for improving efficiency and durability, such as the interfaces of the Cu2O light absorber, protective overlayers, and co-catalysts. It proposes translating high-efficiency thin-film device architectures into photocatalytic sheets or particles as a disruptive approach to solar hydrogen generation, offering opportunities for new scientific discoveries.