Scandium-III-nitrides: A New Material Platform for Semiconductor Photocatalysts with High Reducing Power

Semiconductor nanowires have become emerging photocatalysts in artificial photosynthesis processes for solar fuel production. For reduction reactions, semiconductor photocatalysts with high reducing powers are highly desirable, especially for chemicals that are extremely difficult to reduce. This study introduces a new semiconductor photocatalyst, scandium (Sc)-III-nitrides, which have higher reducing powers than all conventional semiconductor photocatalysts. In specific, we focus on Sc_<i>x</i>Ga_1-<i>x</i>N (ScGaN) nanowires. The detailed material synthesis and characterization of such nanowires are explored, and the photocatalytic reduction of carbon dioxide (CO₂), as an example of chemicals that are difficult to reduce, is also performed. The photocatalytic CO₂ reduction using GaN, a well-known high-performance semiconductor photocatalyst, is conducted as well as a reference. It is found that compared to using GaN nanowires, using ScGaN nanowires can significantly increase the production rate of formic acid (HCOOH). Moreover, ScGaN nanowires can further reduce HCOOH to methanol (CH₃OH).