Catalyst Design at the Nanoscale: Materials and Modifications Powering Photoelectrochemical CO ₂ Conversion

ABSTRACT The increasing demand for sustainable energy has driven research into technologies that address carbon dioxide mitigation and renewable energy storage. Solar‐driven photoelectrochemical (PEC) CO 2 conversion is a promising approach that directly uses sunlight to convert CO 2 into fuels and valuable chemicals. This review provides a comprehensive overview of PEC CO 2 reduction, covering fundamental principles such as photon absorption, charge separation, and catalytic reaction pathways. We highlight recent advancements in material design, focusing on light absorbers, catalysts, and electrode architectures that enhance efficiency, selectivity, and stability. Furthermore, we discuss cutting‐edge strategies for enhancing solar fuel production, such as novel system designs, interface engineering, and co‐catalyst integration. These approaches have the potential to address current challenges and move PEC technology towards practical application.