Bandgap‐Regulation for Directly Solar Energy Conversion in Zinc‐Air Battery with 4.55% PCE

Abstract Direct conversion of solar energy in zinc‐air batteries (SZABs) represents a promising direction for energy storage with huge market potential. However, the key issue to be overcome is the pronounced photo‐generated carrier recombination and a mismatch in optoelectronic‐catalytic properties. Here, we report an atomic‐ level bandgap‐engineering regulation method to unlock high‐efficiency solar energy harvesting and catalytic activation in SZABs based on nitrogen‐substituting graphdiyne (N‐GDYs). The bandgap‐regulation creates tailored electronic structures of N‐GDYs, which not only extends the light absorption range, but also enhances the ability of separation and migration of photo‐generated carriers. Interestingly, the 2N‐GDY demonstrates superior photocatalytic performance, due to its optimal matching bandgap structure. The resulting SZABs device employing 2N‐GDY achieves exceptional battery efficiency of 96.8% under visible light illumination, accompanied by a remarkably low voltage gap of 0.04 V. Notably, under monochromatic light excitation, the system demonstrates enhanced light utilization through wavelength‐selective absorption, achieving a power conversion efficiency (PCE) of up to 4.55%. This work fundamentally advances the rational design of 2D catalytic materials, offering a critical pathway toward high‐efficiency solar rechargeable energy systems that bridge the gap between sustainable energy harvesting and storage.