Chemical‐Stabilized Aldehyde‐Tuned Hydrogen‐Bonded Organic Frameworks for Long‐Cycle and High‐Rate Sodium‐Ion Organic Batteries

Abstract

Hydrogen‐bonded organic frameworks (HOFs) are considered as potential choice for future energy storage systems due to their adjustable chemistry, environment friendliness, and cost‐effectiveness. In this study, structurally stabilized and aldehyde‐tuned hydrogen‐bonded organic frameworks (HOFs‐8) are designed and prepared to contain arrayed electronegative sites for sodium‐ion storage. Benefitting from the flexible hydrogen bond and unique structural symmetry, HOFs‐8 can achieve efficient utilization of the active sites and fast transport of sodium ions and electrons. The HOFs‐8 electrode exhibits an impressive lifespan of 5000 cycles at 3.66 A g−1 (20 C). In situ Fourier Transform infrared spectroscopy (in situ FT‐IR) and ex situ X‐ray Photoelectron Spectroscopy (ex situ XPS) analyses are performed to illustrate the mechanism of sodium‐ion storage involving aldehyde‐tuned C═O. Additionally, flexible hydrogen bonds in HOFs materials with unique structural symmetries are investigated to elucidate the mechanism of hydrogen bonding for improving their electrochemical properties. Density functional theory (DFT) simulations verified that HOFs‐8 has excellent Na+ diffusion kinetics, enabling it to demonstrate outstanding rate capability. This work offers insight into the design of new electrodes and improved HOFs, which are expected to have tremendous potential in energy storage systems.

2,2′‐Thienoviologens with Low Reduction Potential for Electrochromism and Visible‐Light‐Driven Hydrogen Evolution Using g‐C3N4‐Based Composites via Hydrogen Bonds

“…[33b,42] The comparative analysis of the O 1s spectra of g-C 3 N 4 with those of the composites revealed the emergence of a distinct peak at 533.48 eV, indicating the presence of C─O bonds (Figure S52, Supporting Information). [43] The presence of a peak at 531 eV corresponding to ─OH in the g-C 3 N 4 spectrum is believed to be due to the absorption of H 2 O, a phenomenon noticeably amplified following the amalgamation of 4, suggesting the effective incorporation of hydroxyl groups. [44] Given the significance of catalyst durability in real-world scenarios, it is imperative to investigate the durability of the g-C 3 N 4 /1 wt.% 4/1 wt.% Pt composites.…”

Flexible hydrogen-bonded organic frameworks (HOFs): opportunities and challenges

“…Unlike MOFs and COFs, which are constructed through strong coordination or covalent bonds, the weaker bond strength and flexible feature of H-bonds lead to challenges in terms of stability and structural design of HOFs, but at the same time, bring new opportunities for structural diversity and flexibility. [10][11][12][13][14][15][16][17][18][19][20][21][22] In recent years, HOFs have shown great potential in gas storage/separation, sensing, proton conduction, etc.…”

Single atom intercalation in 2D triazine-based (g-C6N6) and boroxine-based (B6O6) porous covalent organic framework bilayers and heterostructures

“…23 Atom intercalation, which involves introducing an atom into the interlayer gap of 2D materials, is a promising technique for enhancing photocatalysis, energy storage, and optoelectronic manipulation. [24][25][26][27][28][29] Confinement of a single atom between layers also induces structural modifications, changing the interlayer distance, which directly correlates with the interaction strength between the atom and BL/HTS. 30,31 Additionally, the presence of pores within the porous materials, providing active sites for anchoring atoms, significantly enhances intercalation capabilities by facilitating the adsorption and intercalation processes of atoms and ions.…”