Developing efficient electrocatalysts for urea oxidation reaction (UOR) can be a promising alternative strategy to substitute the sluggish oxygen evolution reaction (OER), thereby producing hydrogen at a lower cell-voltage. Herein, we synthesized a binder-free thin film of ultrathin sheets of bimetallic Cu-Fe-based metal–organic frameworks (Cu/Fe-MOFs) on a nickel foam via a drop-casting route. In addition to the scalable route, the drop-casted film-electrode demonstrates the lower UOR potentials of 1.59, 1.58, 1.54, 1.51, 1.43 and 1.37 V vs. RHE to achieve the current densities of 2500, 2000, 1000, 500, 100 and 10 mA cm⁻², respectively. These UOR potentials are relatively lower than that acquired by the pristine Fe-MOF-based film-electrode synthesized via a similar route. For example, at 1.59 V vs. RHE, the Cu/Fe-MOF electrode exhibits a remarkably ultra-high anodic current density of 2500 mA cm⁻², while the pristine Fe-MOF electrode exhibits only 949.10 mA cm⁻². It is worth noting that the Cu/Fe-MOF electrode at this potential exhibits an OER current density of only 725 mA cm⁻², which is far inconsequential as compared to the UOR current densities, implying the profound impact of the bimetallic cores of the MOFs on catalyzing UOR. In addition, the Cu/Fe-MOF electrode also exhibits a long-term electrochemical robustness during UOR.

In this study, the effect of Co2+x:Eu2O3 (x = 5, 10 wt. %) bimetallic oxide nanostructures (NS) on dielectric and cis-trans photoisomerization of liquid crystals (LC) has been studied. First, the Co2+:Eu2O3 NS were synthesized by facile coprecipitation method, and then the as-synthesized NS were characterized by x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy, Brunauer Emmett Teller, and UV-visible analytical techniques. New composite structures were prepared by doping Co2+:Eu2O3 (5, 10 wt. %) over liquid crystal (LC) molecules (compounds 4 and 5) containing oxazole moiety. Optical absorption spectra of liquid crystalline NS (LCNS) showed a maximum absorption peak (λmax) between 350 and 450 nm. A significant improvement in the dielectric constants (ɛ′ and ɛ″) was noticed for LC-4 (compound 4)/LC-5 (compound 5) doped with Co2+ (10 wt. %):Eu2O3 NS. The photoisomerization studies of the Co2+ (10 wt. %):Eu2O3 doped to LC-5 (LCNS-2) containing oxazole moiety showed enhanced properties in solution and exhibited photoisomerization in 40 s whereas reverse process (thermal back relaxation) takes 358 s. Furthermore, it was observed that semiconductor NS especially Co2+ (10 wt. %):Eu2O3 NS doped LC-compounds showed enhanced dielectric and photoisomerization properties and can be a potential candidate for optoelectronics and photonic applications.