Novel Ni–Co–P hollow nanobricks are constructed with oriented nanosheets and manifest as an excellent bifunctional electrocatalyst for overall water splitting.

Hollow nanostructures with mesoporous shells are attractive for their advantageous structure-dependent high-efficiency electrochemical catalytic performances. In this work, a novel nanostructure of Fe-doped CoP hollow triangle plate arrays (Fe-CoP HTPAs) with unique mesoporous shells is designed and synthesized through a room-temperature postsynthetic ligand exchange reaction followed by a facile phosphorization treatment. The mild postsynthetic ligand exchange reaction of the presynthesized ZIF-67 TPAs with K [Fe(CN) ] in an aqueous solution at room temperature is of critical importance in achieving the final hollow nanostructure, which results in the production of CoFe(II)-PBA HTPAs that not only determine the formation of the interior voids in the nanostructure, but also provide the doping of Fe atoms to the CoP lattice. As expected, the as-prepared mesoporous Fe-CoP HTPAs exhibit pronounced activity for water splitting owing to the advantages of abundant active reaction sites, short electron and ion pathways, and favorable hydrogen adsorption free energy (ΔG ). For the hydrogen and oxygen evolution reactions with the Fe-CoP HTPAs in alkaline medium, the low overpotentials of 98 and 230 mV are observed, respectively, and the required cell voltage toward overall water splitting is only as low as 1.59 V for the driving current density of 10 mA cm .

An important result of research on mixed-lanthanide metal-organic frameworks (M'LnMOFs) is the realization of highly sensitive ratiometric luminescent thermometers. Here, we report the design and synthesis of the new M'LnMOF Tb0.80Eu0.20BPDA with high relative sensitivity in the physiological temperature regime (298-318 K). The emission intensity and luminescence lifetime were investigated and compared to those of existing materials. It was found that the temperature-dependent luminescence properties of Tb0.80Eu0.20BPDA are strongly associated with the distribution of the energy levels of the ligand. Such a property can be useful in the design of highly sensitive M'LnMOF thermometers.

In this work, we prepared two types of isostructural Ln 3+ -based metal−organic frameworks (LnMOFs) under solvothermal conditions, where two structurally similar pyridine-containing dicarboxylate ligands, 6-(4-carboxyphenyl)nicotinic acid and [2,2′-bipyridine]-5,5′-dicarboxylic acid, were used as the organic linkers. The as-synthesized LnMOF compounds were characterized using single-crystal X-ray diffraction (XRD), powder XRD, and thermogravimetric analysis. With the lanthanide co-doping approach, two mixed LnMOFs, Tb 0.95 Eu 0.05 cpna and Tb 0.95 Eu 0.05 bpydc, were obtained and evaluated for application as potential ratiometric luminescence thermometers. The temperature-dependent luminescence of the two materials was investigated, and their emission intensities, luminescence lifetimes, and thermometric parameters were compared. They exhibit an excellent S-shaped response for temperatures in the range of 25−300 K, with favorable relative sensitivity and temperature uncertainty. Moreover, their color changes from green at 25 K to red at 300 K, so that they are also suitable as colorimetric luminescent probes.