Boosting the Loading of Metal Single Atoms via a Bioconcentration Strategy

Abstract

Increasing the mass loading of transition metal single atoms coordinated with nitrogen in carbon‐based materials (M‐N‐C) is still challenging. Herein, inspired by the bioconcentration effect in the living body, a biochemistry strategy for the synthesis of Fe‐N‐C single atoms is demonstrated. Through introducing ferrous glycinate into the growth of fungus, the Fe atoms are bioconcentrated in hyphae. The highly dispersed Fe‐N‐C single atoms in hyphae‐derived carbon fibers (labeled as Fe‐N‐C SA/HCF) are prepared by the pyrolysis of Fe‐riched hyphae. In the bioconcentration process, the uptake of Fe ions by hyphae promotes the secretion of glutathione and ferritin, which provides additional coordination sites for Fe ions. Accordingly, the mass content of Fe in bioconcentrated Fe‐N‐C SA/HCF reaches 4.8%, which is 5.3 times larger than that of the sample prepared by the conventional pyrolysis process. The present bioconcentration strategy is further extended to the preparation of Co, Ni, and Mn single atoms. Owing to the high content of Fe‐N‐C single atoms, Fe‐N‐C SA/HCF shows the onset potential (Eonset) of 0.931 V versus reversible hydrogen electrode (RHE) and half‐wave potential (E1/2) of 0.802 V versus RHE in oxygen reduction reaction measurements, which is comparable to the commercial Pt/C catalysts.

Synthesis of Uranium Single Atom from Radioactive Wastewater for Enhanced Water Dissociation and Hydrogen Evolution

“…[1][2][3] At present, the uranium in radioactive wastewater is generally treated by the series of extraction, solidification, and landfill, inducing the massive abandonment of uranium resource. [4][5][6][7] In another aspect, uranium has a variety of valences ranging from +3 to +6 because radioactive wastewater was deposited on the MoS 2 nanosheets with precise mass loading and high selectivity for the common coexisting ions. In this case, the uranium was distributed on the sulfur edge (S-edge) sites and defect sites of MoS 2 in the existence form of U(IV) single atoms.…”

Nacre-Inspired Black Phosphorus/Nanofibrillar Cellulose Composite Film with Enhanced Mechanical Properties and Superior Fire Resistance

“…In recent years, scientific researchers have taken a lot of inspiration from nature, like special life processes in the living body, particular structures of natural substances et al and so forth, providing abundant sources for scientific innovation. − Nacre is an organic–inorganic hybrid natural layered structure material created from the long-term evolution of nature, which contains 95 vol % inorganic aragonite platelets with 5 vol % biological nanofibrillar chitin and proteins. , Benefitting from its multistage, ordered “brick-and-mortar” structure, natural nacre is endowed with extraordinary toughness and strength. Inspired by this unique, layered structure, researchers have prepared a series of bionic layered composites with lightweight, high-strength, good toughness, and excellent mechanical properties by different methods. − …”

Recent progress on the synthesis and oxygen reduction applications of Fe-based single-atom and double-atom catalysts

“…These complexes not only can carry out fast redox reactions toward the ORR, but also exhibit excellent electrocatalytic activity in the OER, HER, CO 2 RR and other reactions. 101,103,104 Zhou reported an atomic Fe and N co-doped ordered mesoporous carbon nanosphere (meso-FeÀN-C), which showed excellent ORR activity (Fig. 1a and b).…”