Highly Luminescent Eu3+-Incorporated Zr-MOFs as Fluorescence Sensors for Detection of Hazardous Organic Compounds in Water and Fruit Samples.

Considering the risk of toxic organic compounds to both human health and the environment, highly luminescent Eu3+-incorporated amino-functionalized zirconium metal-organic frameworks, namely, Eu/MOF and Eu@MOF were synthesized via the solvothermal method. The synthesized luminescent europium-incorporated MOFs act as outstanding sensor materials for diphenylamine and dinitrobenzene detection in water and fruit samples. The synergistic effect of Eu3+ metal ions and amino-functionalized MOFs enhances the luminescent properties of the MOFs improving the fluorescence sensing ability toward the analytes. The enhancement in the detection capacity of the Eu3+-incorporated sensors than the sole MOF toward toxic organic compounds was confirmed using the Stern-Volmer equation of limit of detection (LOD) measurements along with fluorescence lifetime measurements. The sensors exhibited turn-on fluorometric detection toward their respective analytes due to the inner filter effect. The plausible fluorescence sensing mechanism has been studied. The DFT calculations have been integrated to study the structure, stability, and charge transfer processes.

Mesoporous SBA-15 supported gold nanoparticles for solvent-free oxidation of cyclohexane: superior catalytic activity with higher cyclohexanone selectivity.

Surface modification of mesoporous SBA-15 with (3-mercaptopropyl) trimethoxysilane greatly enhances its capability to adsorb the tetrachloroauric anion (AuCl4-). The calcination of the sample after the adsorption experiment led to the generation of homogeneously dispersed, spherical, single crystalline gold nanoparticles (Au0 NPs) of less than 5 nm size, embedded on SBA-15 as observed from the TEM images. The as-prepared SBA-15/Au0 nanohybrid material has offered excellent catalytic activity for the selective oxidation of cyclohexane using TBHP as the oxidant in the absence of any solvent. A maximum of 48.7% cyclohexane conversion was achieved and surprisingly, cyclohexanone (K) has much higher selectivity (>95%) than cyclohexanol (A). The hot-filtration study confirmed the leach-resistant characteristics as well as the true heterogeneous catalytic activity of the SBA-15/Au0 nanohybrid catalyst. The catalyst was recycled up to four times without significant loss in its catalytic activity.