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

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.