Photoswitchable Zirconium MOF for Light-Driven Hydrogen Storage

Abstract

Here, we report a new photosensitive metal–organic framework (MOF) that was constructed via the modification of UiO-66-NH2 with diarylethene molecules (DAE, 4-(5-Methoxy-1,2-dimethyl-1H-indol-3-yl)-3-(2,5-dimethylthiophen-3-yl)-4-furan-2,5-dione). The material that was obtained was a highly crystalline porous compound. The photoresponse of the modified MOF was observed via UV–Vis and IR spectroscopy. Most of the DAE molecules inside of the UiO-66-pores had an open conformation after synthesis. However, the equilibrium was able to be shifted further toward an open conformation using visible light irradiation with a wavelength of 520 nm. Conversely, UV-light with a wavelength of 450 nm initiated the transformation of the photoresponsive moieties inside of the pores to a closed modification. We have shown that this transformation could be used to stimulate hydrogen adsorption–desorption processes. Specifically, visible light irradiation increased the H2 capacity of modified MOF, while UV-light decreased it. A similar hybrid material with DAE moieties in the UiO-66 scaffold was applied for hydrogen storage for the first time. Additionally, the obtained results are promising for smart H2 storage that is able to be managed via light stimuli.

Impact of Polymers on Magnesium-Based Hydrogen Storage Systems

“…The safe and efficient technique is to store the hydrogen in the solid state of material-based hydrogen storage systems [77,78]. In material-based hydrogen storage systems, the hydrogen can be stored in two forms: (i) physical adsorption on the material and (ii) stored through chemical bonds [79,80]. Among the different hydrogen storage materials, magnesium (Mg) has been considered one of the excellent materials for hydrogen storage material because of its different forms in hydrides [81][82][83][84].…”

Photoresponsive Metal-Organic Frameworks as Adjustable Scaffolds in Reticular Chemistry

“…These molecules easily exchange the open ring and closed ring forms by the application of a photochemical stimulus (Figure 5). Along with their diverse structural functionalization, diarylethenes are suitable candidates for the development of photoresponsive metal-organic porous materials due to their exceptional photoreactivity and thermal stability [65][66][67]. grey = thorium clusters; red = rods representing the azobenzene ligand 2 and n azo functionality; light grey = carbon atoms; white = hydrogen atoms; purple =…”

Li Decorated Penta-BCN as a Competitive Reversible Hydrogen Storage Media: A First-Principles Study

“…An ideal hydrogen storage medium should possess desirable characteristics, such as adequate binding energy for Kubas-type interactions ranging from 0.1 to 0.8 eV/H 2 ; chemisorption and physisorption; high hydrogen loading capacity (>5.5 wt %) for efficient storage; high gravimetric capacity; a lightweight composition; excellent stability for commercial transportation and preservation; and an environmentally friendly chemical composition with minimal environmental impact . In response to these considerations, researchers have focused on various nanostructure materials, such as two-dimensional (2D) sheets, ,− metal atom-modified covalent organic frameworks, and a metal organic frameworks, − since they can significantly improve kinetics during the absorption process by decreasing the enthalpy of formation and hydrogenation temperature, along with other catalytic effects. Among these materials, 2D materials with a high surface-to-volume ratio and active site density show the most promise.…”