Atomically Dispersed Semimetallic Selenium on Porous Carbon Membrane as an Electrode for Hydrazine Fuel Cells

Abstract

Electrochemically functional porous membranes of low cost are appealing in various electrochemical devices used in modern environmental and energy technologies.H erein we describe as calable strategy to construct electrochemically active,h ierarchically porous carbon membranes containing atomically dispersed semi-metallic Se,d enoted SeNCM. The isolated Se atoms were stabilized by carbon atoms in the form of ah exatomic ring structure,i nw hich the Se atoms were located at the edges of graphitic domains in SeNCM. This configuration is different from that of previously reported transition/noble metal single atom catalysts.T he positively charged Se,e nlarged graphitic layers,r obust electrochemical nature of SeNCM endow them with excellent catalytic activity that is superior to state-of-the-art commercial Pt/C catalyst. It also has long-term operational stability for hydrazine oxidation reaction in practical hydrazine fuel cell.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Single Semi‐Metallic Selenium Atoms on Ti3C2 MXene Nanosheets as Excellent Cathode for Lithium–Oxygen Batteries

“…In sharp contrast, the corresponding maximum in Figure 2g,h located at 9.5 Å −1 (SeSe) and 5.6 Å −1 (SeO) can be, respectively, observed in Se foil and SeO 2 standard sample. [24,31] More detailed EXAF curve fitting parameters of SASe-Ti 3 C 2 catalyst are exhibited in Table S2, Supporting Information. To sum up, advanced characterization including XPS, Raman, and synchrotron XAS can adequately identify the formation of SeC bonds, and further prove that Se SAs partially occupy surface Ti-vacancies, which can favor rapid charge transmission during ORR/OER process.…”

“…Selenium atoms possessing large atom size, rich d-electron, and high electro polarizability as a chalcogen has been identified to significantly improve the electron transfer efficiency of 2D substrates. [24] For SASe-Ti 3 C 2 catalyst, Se SAs are embedded in the surface Ti-vacancies of Ti 3 C 2 nanosheets and further build strong interaction with high conductivity MXenes framework, which can significantly reduce charge transfer resistance and increase the number of nucleation sites of discharge Li 2 O 2 products. Density functional theory (DFT) calculations demonstrate that the intermediates adsorption behavior and charge transport ability could be significantly enhanced by virtue of atomically dispersed Se catalysis centers, which can further modulate the size, morphology, and distribution of Li 2 O 2 products.…”

Single‐Atom Materials: Small Structures Determine Macroproperties

“…Wang and coworkers first reported a SAM consisting of atomic Se atoms supported by the porous carbon membrane (named as the SeNCM, Figure 3d), which was demonstrated to be the efficient catalyst for hydrazine oxidation reaction (HzOR) in hydrazine fuel cells (HzFCs). [ 33 ] Compared with Se powder, the SeNCM‐1000 shows a totally different catalytic activity toward HzOR, which has an onset potential and peak current density of 0.43 V [vs reversible hydrogen electrode (RHE)] and 30.8 mA cm −2 , respectively. Together with the structure fitting results, it can be indicated that there is large overlapping in orbitals between Se and coordinated C atoms, resulting in a valence state of about +3.…”

Crosslinking of a Single Poly(ionic liquid) by Water into Porous Supramolecular Membranes

“…Poly(ionic liquid)s (PILs) have recently emerged as non‐conventional polyelectrolytes that contain an IL species in their repeating unit, providing a multifunctional materials platform in the membrane field . Recently, we developed scalable freestanding PPMs by electrostatic crosslinking of a hydrophobic PIL with a PIL‐derived polyanion; this discovery spawned a myriad of functional materials for various applications . However, challenges remain here to make PPMs structurally reversible and reusable to become adaptive smart materials.…”