An overview of converting reductive photocatalyst into all solid-state and direct Z-scheme system for water splitting and CO₂ reduction

Considering the current scenario of rising environmental and energy concerns, engineering of Z-scheme photocatalytic systems is in the spotlight. The prime reason for this includes efficient redox abilities and effective space separation along with the migration of photoinduced charge carriers over conventional heterojunction systems. Herein we foreground the stumbling blocks of traditional heterojunction systems and enlighten the generations of Z-scheme photocatalysis originating from liquid-phase to direct Z-scheme photocatalytic systems. We provide substantial criteria and selection aspects of choosing reductive type photocatalysts as a potential aspirant for the Z-scheme photocatalytic system. As Z-scheme photocatalytic systems render effective space separation of photogenerated carriers, active species generation, wide optical absorption and amended redox ability. We focus on comprehensive illustration of all solid-state and direct Z-scheme photocatalysts by coupling reductive type photocatalysts with other semiconductor material and explored their potential for efficacious conversion of solar energy into functional energy. Herein, we aim to provide in-depth and updated criteria for selecting Z-scheme photocatalysts for CO₂ reduction, water splitting, and nitrogen fixation. Lastly, the article compiles with a conclusive note about future perspectives and challenges accompanying all solid-state and direct Z-scheme Z photocatalysts and their energy conversion applications.