Ag nanoparticles loaded onto Sn-based MOF with “memory catalysis” effect for photocatalytic continuous degradation of Methyl Orange

Ag was loaded onto Sn-PTA-MI by the photodeposition method. • Dark reaction experiment confirms Sn-PTA-MI/Ag has the “memory catalysis” effect. • “Memory catalysis” effect boosted by free radical chain reaction from released electrons. • Alternating light-dark reaction enhances utilization efficiency of photogenerated carriers. • PDOS spectroscopy confirms strong interaction between Ag atoms and N, C atoms. A Sn-PTA-MI/Ag photocatalyst with “memory catalysis” effect was prepared by the photodeposition method to load Ag onto Sn-based metal-organic framework (MOF), and the “memory catalysis” effect was confirmed by photoreaction, dark reaction, and alternating light-dark reaction experiments. Under photoreaction, the degradation efficiency of methyl orange (MO) catalyzed by Sn-PTA-MI/Ag reached 90.7% in 60 min. The pre-illumination activation of the Sn-PTA-MI/Ag catalyst facilitated the storage of photogenerated electrons, which are released under dark reaction conditions and subsequently participate in MO degradation. Meanwhile, the “memory catalysis” effect can be significantly enhanced through the free radical chain reaction triggered by the released electrons under dark reaction. The alternating light-dark reaction process achieves continuous degradation of MO, and compared to traditional photocatalytic reactions, the degradation effect of MO is improved by approximately 10%. Projected density of states (PDOS) and Fermi level analysis indicate that strong interactions exist between Ag atoms and N, C atoms, confirming that the optimization of electronic properties and the enhancement of charge separation in the Sn-PTA-MI/Ag system are the main reasons for the increase in activity. This study provides a strategy for the continuous degradation of pollutants, which is of great significance for sustainable environmental remediation. Download: Download high-res image (180KB) Download: Download full-size image