Dual Electric Fields Enable Ultrafast Charge Migration in Photochromic Amorphous/Crystalline ZnCdS for Simultaneous Hydrogen Evolution and Wastewater Remediation

Abstract

Directional charge migration across both the bulk and the interface remains a key bottleneck for achieving high-efficiency photocatalysts. Herein, we develop a photochromic amorphous/crystalline ZnCdS (A/CZCS) photocatalyst with dual electric fields to achieve ultrafast charge migration. Specifically, the amorphous ZnCdS induce a strong dipole field, while the A/CZCS generates an internal electric field. The synergistic coupling of these dual electric fields enables directional charge migration between amorphous and crystalline interface. To further accelerate electron utilization, MoS2 is coupled with A/CZCS to form a ternary heterointerface, which effectively suppresses charge recombination and accelerates surface reaction kinetics. Benefiting from the synergistic effects of dual electric fields and directional charge transport mechanism, the A/CZCS/MoS2 photocatalyst achieves an ultrahigh hydrogen evolution rate of 21.73 mmol g-1 h-1 without noble-metal cocatalysts, 310 times higher than that of crystalline ZnCdS, and simultaneously achieves complete degradation of various organic pollutants within 10 min in the same system. The apparent quantum efficiency reaches 72% at 350 nm, surpassing previously reported systems. Furthermore, a flexible 9 cm × 7 cm film fabricated via a simple blade-coating method produces abundant H2 bubbles under natural sunlight, underscoring its scalability and practical potential.