Hydrolysis of Dimethyl Phosphite by Zr- and Hf-UiO-66.

Metal-organic frameworks have been utilized as heterogeneous catalysts for the degradation of chemical warfare agents, typically organophosphorous nerve agents. Vibrational spectroscopy techniques coupled with nuclear magnetic resonance (NMR) were utilized to study the adsorption and degradation of dimethyl phosphite (DMP), a simulant molecule of the organophosphorus nerve agent Soman (GD), by Zr- and Hf-UiO-66 as a function of particle size, defect type, and defect density. Defective Zr- and Hf-UiO-66 have been synthesized via a modulated synthesis protocol to engineer missing linker and missing cluster defects into the crystal structure.

Vibrational spectroscopy investigation of defects in Zr- and Hf-UiO-66.

Defect engineering in metal-organic framework compounds has allowed for improvements in catalysis-based functionalities, gas sensing, and gas storage. Metal-organic framework UiO-66 compounds with Zr- and Hf-based metal secondary building units were studied with Raman and infrared vibrational spectroscopy. Missing linker and missing cluster defects were engineered into the crystal structure a modulated synthesis technique.

Investigation of band gap narrowing in nitrogen-doped La2Ti2O7 with transient absorption spectroscopy.

Doping a semiconductor can extend the light absorption range, however, it usually introduces mid-gap states, reducing the charge carrier lifetime. This report shows that doping lanthanum dititinate (La2Ti2O7) with nitrogen extends the valence band edge by creating a continuum of dopant states, increasing the light absorption edge from 380 nm to 550 nm without adding mid-gap states. The dopant states are experimentally resolved in the excited state by correlating transient absorption spectroscopy with a supercontinuum probe and DFT prediction.