Persistent luminescent ZnAl-LDH nanosheets for all-weather degradation of nitenpyram and tetracycline: Superoxide radical induction, life cycle analysis and engineering applications

Photocatalysts designed for all-weather applications, capable of efficient charge carrier separation, are set to transform the adoption of photocatalysis-driven advanced oxidation processes in wastewater management. In this investigation, an energy-storing ZnAl-LDH@SrAl₂O₄:Eu²⁺, Dy³⁺ (SALDH) was synthesized successfully, optimized for the photocatalytic selective degradation of NTP and tetracycline hydrochloride (TC) under varying weather conditions, with 100 % degradation of both NTP and TC within 75 min. Remarkably, SALDH demonstrates energy storage capabilities that markedly reduce energy demands relative to traditional photocatalytic approaches. The primary reactive species identified were O₂⁻, and the Fukui index, computed via density-functional theory (DFT), identified the specific interaction sites of O₂⁻ on NTP molecules. Utilizing the energy retention properties of SALDH, a novel, environmentally friendly device was engineered for processing organic pollutants in agricultural wastewater. This system harness the energy from solar radiation to induce the oxidation of pollutants. The experiments that were performed in the both artificially prepared lab-scale and actual agricultural WWT plants indicated the degradation efficiencies of 36 % and 37 %, respectively. As seen during the day, both SALDH and persulfate were capable of effectively decomposing organic contaminants; at night, the SA’s luminescence maintained the oxidative ability of ZnAl-LDH. Meanwhile, SALDH combines the corrosion resistance of ZnAl-LDH with good metal compatibility, enabling SALDH to effectively improve the photostability of long afterglow. This work contributes to the existing knowledge on the degradation of organic pollutants by efficient photocatalysts and points to possible implementations in water treatment processes.