Atomically Dispersed Iron with Densely Exposed Active Sites as Bifunctional Oxygen Catalysts for Zinc-Air Flow Batteries.

Atomically dispersed iron embedded carbon is a promising bifunctional catalyst for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), but its exposed iron sites must be increased. Herein, the authors propose a double steric hindrance strategy by using zeolitic imidazolate frameworks-8 as the first barrier skeleton and encapsulated phenylboronic acid as the second space obstruction to realize densely exposed atomic iron sites. Prepared PA@Z8-FeNC has the highest iron content (5.

Synergistically Optimized Electron and Phonon Transport of Polycrystalline BiCuSeO Pb and Yb Co-Doping.

Polycrystalline BiCuSeO is considered as a promising thermoelectric material due to its intrinsically low thermal conductivity and moderate Seebeck coefficient. However, its low electrical conductivity and coupled electron-phonon transport properties restrict the further improvement of the thermoelectric performance. In this work, Pb and Yb dopants are incorporated into BiCuSeO to substitute for Bi sites ball milling and high-pressure and high-temperature sintering, leading to a synergistic optimization of the electron and phonon transport and improved thermoelectric performance.

Multiple Roles of Unconventional Heteroatom Dopants in Chalcogenide Thermoelectrics: The Influence of Nb on Transport and Defects in BiTe.

Improvements in the thermoelectric performance of n-type BiTe materials to more closely match their p-type counterparts are critical to promote the continued development of bismuth telluride thermoelectric devices. Here the unconventional heteroatom dopant, niobium, has been employed as a donor in BiTe. Nb substitutes for Bi in the rhombohedral BiTe structure and exhibits multiple roles in its modulation of electrical transport and defect-induced phonon scattering.

Facile Synthesis of Hierarchical Nanosized Single-Crystal Aluminophosphate Molecular Sieves from Highly Homogeneous and Concentrated Precursors.

The synthesis of hierarchical nanosized zeolite materials without growth modifiers and mesoporogens remains a substantial challenge. Herein, we report a general synthetic approach to produce hierarchical nanosized single-crystal aluminophosphate molecular sieves by preparing highly homogeneous and concentrated precursors and heating at elevated temperatures. Accordingly, aluminophosphate zeotypes of LTA (8-rings), AEL (10-rings), AFI (12-rings), and -CLO (20-rings) topologies, ranging from small to extra-large pores, were synthesized.