Embedding Atomically Dispersed Iron Sites in Nitrogen‐Doped Carbon Frameworks‐Wrapped Silicon Suboxide for Superior Lithium Storage

Abstract

Silicon suboxide (SiO x ) has attracted widespread interest as Li-ion battery (LIB) anodes. However, its undesirable electronic conductivity and apparent volume effect during cycling impede its practical applications. Herein, sustainable rice husks (RHs)-derived SiO 2 are chosen as a feedstock to design SiO x /iron-nitrogen co-doped carbon (Fe-N-C) materials. Using a facile electrospray-carbonization strategy, SiO x nanoparticles (NPs) are encapsulated in the nitrogen-doped carbon (N-C) frameworks decorating atomically dispersed iron sites. Systematic characterizations including high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and X-ray absorption fine structure (XAFS) verify the existence of Fe single atoms and typical coordination environment. Benefiting from its structural and compositional merits, the SiO x /Fe-N-C anode delivers significantly improved discharge capacity of 799.1 mAh g −1 , rate capability, and exceptional durability, compared with pure SiO 2 and SiO x /N-C, which has been revealed by the density functional theory (DFT) calculations. Additionally, the electrochemical tests and in situ X-ray diffraction (XRD) analysis reveal the oxidation of Li x Si phase and the storage mechanism. The synthetic strategy is universal for the design and synthesis of metal single atoms/clusters dispersed N-C frameworks encapsulated SiO x NPs. Meanwhile, this work provides impressive insights into developing various LIB anode materials suffering from inferior conductivity and huge volume fluctuations.

Space‐Confined Metal Ion Strategy for Carbon Materials Derived from Cobalt Benzimidazole Frameworks with High Desalination Performance in Simulated Seawater

“…In addition, the cubic structure of CoZIF9 after pyrolysis can make the Co nanoparticles or other metal particles uniformly confined into the carbon skeleton, along with exposing more metal active sites and significantly enhancing the capacitive properties. [37][38][39][40] The schematic diagram in Figure 1a illustrates how a series of CoM n+ ZIF9 materials were obtained by a space-confined synthesis strategy with CoZIF9 as the carrier using room-temperature stirring. The morphology of products obtained with different molar ratios (Co/M n+ = 0/1, 1/1, 5/1) varied significantly and deviated from expectations, as revealed by scanning electron microscopy (SEM, Figures S2-S12, Supporting Information).…”

The bio-inspired heterogeneous single-cluster catalyst Ni100–Fe4S4 for enhanced electrochemical CO2 reduction to CH4

“…4e and f ) for Ni100-Fe 4 S 4 and Ni100-Fe 4 S 4 -*CO 2 , respectively. The work function is an essential physical property of metallic materials, 66 which has been widely used in the design and evaluation of various photo/electrocatalysts, [67][68][69] can be obtained by calculating the difference between the electrostatic potential at the vacuum level E vac and the electrostatic potential at the Fermi level E F using ESI eqn (S4) and (S5). † The detailed electrostatic potential and work function calculation formula are given in ESI S3 and S4.…”

Nanoscale MOFs in nanomedicine applications: from drug delivery to therapeutic agents

“…Intensive efforts have been devoted to exploiting biomaterials for preclinical or clinical applications, 1,2 such as diagnosis, therapy and beyond. 3–5 To date, a variety of nanomaterials have been developed as diagnostic agents, therapeutic agents, and even theranostic agents and have made enormous progress in the field of biomedicine due to their tunable size, unique surface characterizations, and high cargo loadings. Notably, nanomaterial-based agents have some intrinsic advantages over their counterparts, such as controllable release, enhanced accumulation, and augmented blood circulation, allowing for boosting the therapeutic efficacy and alleviating adverse reactions.…”