2D Germanane-Based Z-Scheme Heterojunctions for Ultrafast Antibiotic Degradation and Mineralization.

The escalating global concern over antibiotic contamination in aquatic environments demands the development of efficient photocatalytic systems capable of achieving both rapid degradation and deep mineralization. Herein, an all-solid-state Z-scheme heterojunction has been engineered through the rational wet-chemical immobilization of tetrahedral Ag3PO4 nanocrystals onto 2D germanane (2D-GeH) nanosheets, with metallic Ag nanoparticles serving as a pivotal electron mediator. Under visible light irradiation, the resulting 2D-GeH/Ag/Ag3PO4 heterojunction exhibits ultrafast tetracycline (TC) degradation (96.1% in 3 min) together with deep mineralization efficiency (70.5% total organic carbon removal). Mechanistic investigations reveal the pivotal role of superoxide radicals in the degradation process, while chromatographic analyses identify two dominant TC transformation pathways leading to mineralization. Thus, this work highlights the potential of 2D-GeH-based Z-scheme heterojunctions as effective visible-light-driven photocatalysts for effective antibiotic remediation.