Unveiling the Defect‐Accelerated Charge Transfer Mechanism in ZnIn ₂ S ₄ /g‐C ₃ N ₄ Z‐Scheme Heterojunctions for Efficient Solar Fuel Production

Design and fabrication of efficient Z‐scheme heterojunctions are critical for advancing solar fuel production, yet constructing directed interfacial charge transfer pathways remains challenging. Herein, we report ZnIn 2 S 4 /g‐C 3 N 4 Z‐scheme heterojunctions where interfacial defects serve as electron highways for rapid charge separation. These heterostructures exhibit a significant enhancement in CO 2 photoreduction efficiency compared to pristine components, while maintaining > 90% activity after three cycles. Experimental and theoretical analyses confirm that interfacial defects act as charge‐transfer mediators, synergistically accelerating surface redox kinetics to enable efficient solar fuel production (232.92 μmol g − 1 of CO and 10.7 mmol g − 1 of H 2 after 5 h of illumination). This work establishes interfacial defect utilization as an efficient strategy for high‐performance Z‐scheme systems in value‐added chemical synthesis.