Cubic-like Co/NC composites derived from ZIF-67 with a dual control strategy of size and graphitization degree for microwave absorption

Abstract

MOFs with high tunability is considered as an ideal candidate for microwave absorbing materials. Strict experimental conditions can implement repeatability and maximize the potential of materials. In this paper, the...

Hollow C@MoS2 Nanospheres for Microwave Absorption

“…The A D / A G ratios of the MHCS-MoS 2 –1.5 samples treated at 600 and 800 °C are 2.06 and 1.94, respectively, indicating that the A D / A G ratios tend to decrease with the increase in calcination temperature . Increased graphitization led to enhanced electronegativity difference between graphitized and nongraphitized regions, improving edge-induced dipole polarization . Meanwhile, the electronegativity difference between MHCS cores and MoS 2 shells increases, inducing interfacial polarization relaxation.…”

“…28 Increased graphitization led to enhanced electronegativity difference between graphitized and nongraphitized regions, improving edge-induced dipole polarization. 56 Meanwhile, the electronegativity difference between MHCS cores and MoS 2 shells increases, inducing interfacial polarization relaxation. Finally, the effect of graphitization levels of MHCS cores on EMA performances is displayed in 3D contour maps with projections (Figure 8a,b).…”

ZIFs@chitosan Derived Efficient Bimetallic Carbon-Based Catalyst for Oxygen Reduction

“…The XPS spectrum was applied to analyze the surface chemical state of ZnCo-ZIF@CS-n-800 catalysts (Figure 4 and Figure S5). As shown in Figure 4a, the peak at 795.6 eV is designated as the metal Co 0 , 46 and the peaks at 779.7 and 781.4 eV of Co 2p 3/2 are attributed to Co 3+ and Co 2+ , respectively. 44,47 Furthermore, the satellite peak can be found at 804.5 eV for ZnCo-ZIF@CS-1-800 and ZnCo-ZIF@CS-2-800.…”

“…For ZnCo-ZIF@CS-1-800 and ZnCo-ZIF@CS-2-800, only pyrrolic-N peak (400.5 eV) appears in the high-resolution spectrum. However, in the spectra of ZnCo-ZIF@CS-3-800 and ZnCo-ZIF@CS-4-800, in addition to the pyrrolic-N peak, there is also the pyridinic-N peak at 398.6 eV, and the N–O peak (404.5 eV) also appears in the spectrum of ZnCo-ZIF@CS-3-800. , Various states of nitrogen provide an opportunity to improve the catalytic activity of the carbon-based products . It can be observed from the Zn 2p spectra (Figure c) that due to the high Zn content in the ZnCo-ZIF precursor of ZnCo-ZIF@CS-3-800 and ZnCo-ZIF@CS-4-800, Zn 2+ was not completely reduced and removed as the vapor during carbonization, but a small portion remained.…”

Texture Regulation of Metal–Organic Frameworks, Microwave Absorption Mechanism‐Oriented Structural Optimization and Design Perspectives

“…c1) Regulation of MOFs size based on growth temperature. Reproduced with permission [120]. Copyright 2021, Royal Society of Chemistry.…”