Phase‐Engineered Catalysts for Photocatalytic Conversion of C ₁ Molecules

Photocatalytic conversion of C₁ molecules (CO, CO₂, CH₄, CH₃OH, HCOOH, etc.) represents a potential approach for sustainable energy conversion and carbon neutrality. In recent years, phase engineering has been emerging as a promising means to enhance the performances of photocatalysts. By controlling the crystalline phase structures, heterophases, and surface properties of materials, this approach can allow to optimize light absorption, charge separation, and charge transfer to activate of targeted C₁ molecules. In addition, it can also alleviate two core challenges in photocatalytic conversion of C₁ molecules: the competitive formation of multiple side-products and the stability of catalytic sites. This review aims to provide a brief summary of recent research progresses in the field of phase engineering materials, and insights for designing efficient photocatalysts via multi-scale structural regulation. Several possible research perspectives are further suggested, including exploring the phase-performance relationship, dynamic phase-transition mechanisms, and scalable preparation processes to advance future practical applications of photocatalytic technology for the C₁ molecule conversion.