ABSTRACT
Despite rapid technological progress, heavy metal water pollution, and particularly arsenic contamination, remains a significant global challenge. In addition, the stabilization of trivalent arsenic as neutral arsenite (AsIII) species hinders its removal by conventional sorbents. While adsorption of anionic arsenate (AsV) species is in principle more feasible, there are only few adsorbents capable of adsorbing both forms of arsenic. In this work, we explore the potential of two well-known families of Metal-Organic Frameworks (MOFs), UiO-66 and MIL-125, to simultaneously adsorb and photo-oxidize arsenic species from water. Our results demonstrate that the formation of AsV ions upon light irradiation promotes the subsequent adsorption of AsIII species. Thus, we propose the combined utilization of photocatalysis and adsorption with Metal-Organic Framework photocatalysts for water remediation purposes.
ABSTRACT
Hexavalent chromium (Cr(VI)) is a highly mobile cancerogenic and teratogenic heavy metal ion. Among the varied technologies applied today to address chromium water pollution, photocatalysis offers a rapid reduction of Cr(VI) to the less toxic Cr(III). In contrast to classic photocatalysts, Metal-Organic frameworks (MOFs) are porous semiconductors that can couple the Cr(VI) to Cr(III) photoreduction to the chromium species immobilization. In this minireview, we wish to discuss and analyze the state-of-the-art of MOFs for Cr(VI) detoxification and contextualizing it to the most recent advances and strategies of MOFs for photocatalysis purposes. The minireview has been structured in three sections: (i) a detailed discussion of the specific experimental techniques employed to characterize MOF photocatalysts, (ii) a description and identification of the key characteristics of MOFs for Cr(VI) photoreduction, and (iii) an outlook and perspective section in order to identify future trends.
ABSTRACT
Magnetoelastic resonators are gaining attention as an incredibly versatile and sensitive transduction platform for the detection of varied physical, chemical, and biological parameters. These sensors, based on the coupling effect between mechanical and magnetic properties of ME platforms, stand out in comparison to alternative technologies due to their low cost and wireless detection capability. Several parameters have been optimized over the years to improve their performance, such as their composition, surface functionalization, or shape geometry. In this review, the working principles, recent advances, and future perspectives of magnetoelastic resonance transducers are introduced, highlighting their potentials as a versatile platform for sensing applications. First, the fundamental principles governing the magnetoelastic resonators performance are introduced as well as the most common magnetoelastic materials and their main fabrication methods are described. Second, the versatility and technical feasibility of magnetoelastic resonators for biological, chemical, and physical sensing are highlighted and the most recent results and functionalization processes are summarized. Finally, the forefront advances to further improve the performance of magnetoelastic resonators for sensing applications have been identified.