Ruthenium, a transition metal element, has attracted significant attention in the field of photocatalysis due to its distinctive catalytic properties. Ruthenium-based photocatalysts demonstrate strong potential in applications such as photodegradation, photoelectrochemical water splitting, and artificial photosynthesis. This is largely attributed to ruthenium’s high electronic conductivity, broad light absorption capability, and excellent chemical stability, all of which contribute to its outstanding catalytic performance in photocatalytic processes.