Recent advances in semiconductor quantum dots for photocatalytic CO₂ reduction

Developing efficient carbon capture, utilization and storage methods is essential to offset adverse global climate changes. Among those methods, photocatalytic CO₂ conversion is an emerging as an effective and sustainable solution. Among the various photocatalysts, semiconductor quantum dots (QDs) are particularly promising for the CO₂ reduction reaction (CO₂RR) due to their unique features, such as quantum confinement effect, large absorption coefficient, and beneficial surface properties. This review provides a comprehensive and distinctive perspective by integrating three critical dimensions: advanced mechanistic understanding through cutting-edge characterization techniques, systematic stability analysis under realistic operating conditions, and direct CO₂ capture-utilization integration. We highlight recent strategies for improving the CO₂RR performance of QDs, including bandgap tuning, ion doping, defect and heterojunction engineering, ligand modification and cocatalyst loading. We also explore integrated approaches that couple CO₂ capture with photocatalytic conversion. Furthermore, we address the critical transition from laboratory demonstrations to real-world implementation by analyzing long-term stability, degradation mechanisms, and realistic cyclic operating conditions inadequately addressed in current research. Finally, we address prevailing challenges and future prospects, aiming to spark continuous innovation in applying QDs to CO₂ capture and conversion.