Selective synthesis and defects steering superior microwave absorption capabilities of hollow graphitic carbon nitride micro-polyhedrons

Fan, Baoxin; Xing, Lidan; He, Qianmei; Zhou, Fanjie; Yang, Xin; Wu, Tong; Tong, Guoxiu; Wang, Dongmei; Wu, Wenhua

doi:10.1016/j.cej.2022.135086

Cited by 53 publications

(13 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…, the smaller the ratio, the higher the crystallinity. 34 The S D / S G value falls from 1.27 to 1.03 at φ = 0–50 mol% and increases slowly from 1.03 to 1.12 at φ = 50–100 mol%, indicating that a moderate φ is more conducive to the graphitization of carbon. This may be influenced by the oxidoreduction between C and CoO (Fig.…”

Section: Resultsmentioning

confidence: 93%

In situ generated gas bubble-directed self-assembly of multifunctional MgO-based hybrid foams for highly efficient thermal conduction, microwave absorption, and self-cleaning

You¹,

Liu²,

Ying³

et al. 2023

Mater. Horiz.

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 93%

In situ generated gas bubble-directed self-assembly of multifunctional MgO-based hybrid foams for highly efficient thermal conduction, microwave absorption, and self-cleaning

You¹,

Liu²,

Ying³

et al. 2023

Mater. Horiz.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The chemical states of C rings in g-CN/C rings -0.1 were further examined by XPS spectra, as shown in Figure 2d C 1s binding energy can be deconvoluted into three peaks at 284.9, 286.4, and 288.2 eV, which can be ascribed to carbon graphite, CN, and NCN in the g-CN/C rings -0.1 sample, respectively. [38,39] Notably, the strongest C 1s peak shifts from 288.3 eV of pristine g-CN sample to 287.8 eV of g-CN/C rings -0.1, while a decrease in binding energy can also be observed in the N 1 s spectrum, with the strongest N 1 s peak shifting from 398.7 eV of the g-CN sample to 398.3 eV of g-CN/C rings -0.1 (Figure S12a, Supporting Information). This result is mainly due to the chemical bonding of C rings with N in g-CN, which would lead to additional electron redistribution.…”

Section: Resultsmentioning

confidence: 99%

π‐Conjugated In‐Plane Heterostructure Enables Long‐Lived Shallow Trapping in Graphitic Carbon Nitride for Increased Photocatalytic Hydrogen Generation

Zhang

Ren

et al. 2023

Small

View full text Add to dashboard Cite

the development of semiconductor-based photocatalysts that can efficiently split water for durable photocatalytic H 2 production is at the forefront. To date, among numerous photocatalysts that have been demonstrated for H 2 production under exposure to UV and visible light, [4][5][6]56] conjugated graphitic carbon nitride has stood out as one of the most investigated photocatalysts in the past decade owing to the advantages of its suitable energy position for water splitting, visible light harvesting, easy functionalization, and facile preparation from low-cost precursors. [7,55] Nevertheless, pristine g-CN suffers from an exceptionally high charge carrier recombination rate primarily due to the relatively short-lived excited states, such as nascent excitons and shallow trapping states, [8] which results in a low photocatalytic performance. Kinetics studies by ultrafast time-resolved spectroscopy reveal three allowable trapping processes for photoinduced charge carriers in g-CN, including short-lived excitons, shallow trapping states, and deep trapping states. [9,10] Among them, the short-lived excitons and the charges in the shallow trap states play a crucial role in photoactivity enhancement. Hence, increasing the decay lifetime of the excitons and shallow trapping in g-CN are expected to enhance the photocatalytic performance yet less investigated.To date, many strategies have been applied to modulate the photoinduced charge-carrier trapping process in g-CN viaThe relatively short-lived excited states, such as the nascent electron-hole pairs (excitons) and the shallow trapping states, in semiconductor-based photocatalysts produce an exceptionally high charge carrier recombination rate, dominating a low solar-to-fuel performance. Here, a π-conjugated in-plane heterostructure between graphitic carbon nitride (g-CN) and carbon rings (C rings ) (labeling g-CN/C rings ) is effectively synthesized from the thermolysis of melamine-citric acid aggregates via a microwave-assisted heating process. The g-CN/C rings in-plane heterostructure shows remarkably suppressed excited-state decay and increased charge carrier population in photocatalysis. Kinetics analysis from the femtosecond time-resolved transient absorption spectroscopy illustrates that the g-CN/C rings π-conjugated heterostructure produces slower exciton annihilation (τ 1 = 7.9 ps) and longer shallow electron trapping (τ 2 = 407.1 ps) than pristine g-CN (τ 1 = 3.6 ps, τ 2 = 264.1 ps) owing to C rings incorporation, both of which enable more photoinduced electrons to participate in the photocatalytic reactions, thereby realizing photoactivity enhancement. As a result, the photocatalytic activity exhibits an eightfold enhancement in visible-light-driven H 2 generation. This work provides a viable route of constructing π-conjugated in-plane heterostructures to suppress the excited-state decay and improve the photocatalytic performance.

show abstract

“…117 When the electromagnetic wave injects into the interior of the materials, many reflections and oscillations can occur in the hollow cavity, which improves the attenuation of the electromagnetic wave. 118 In addition, the materials with a hollow structure often present the characteristic of light weight, which is usually used as a coating material in the military field. 119 Carbon nanotubes (CNTs) can be considered as tubes made of graphite flakes curled around a central axis, which is a typical 1D hollow nanomaterial.…”

Section: Structure Design Of 1d Emwa Nanomaterialsmentioning

confidence: 99%

“…This topology structure not only has large specific surface area, multiple reflections, and scattering but also can accommodate a large number of guest molecules with different sizes . When the electromagnetic wave injects into the interior of the materials, many reflections and oscillations can occur in the hollow cavity, which improves the attenuation of the electromagnetic wave . In addition, the materials with a hollow structure often present the characteristic of light weight, which is usually used as a coating material in the military field …”

Section: Structure Design Of 1d Emwa Nanomaterialsmentioning

confidence: 99%

Recent Progress of One-Dimensional Nanomaterials for Microwave Absorption: A Review

Wang

Zhu

Han

et al. 2023

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

With the increasing problems of electromagnetic interference and electromagnetic radiation, electromagnetic wave absorption (EMWA) materials have received considerable attention in civil and military fields. Among various EMWA materials, one-dimensional (1D) nanomaterials are recognized as a very promising candidate because of their unique aspect ratio, special shape anisotropy, large specific surface area, and simple manufacturing process. Herein, this paper presents a comprehensive review of recent research progress of 1D nanomaterials for EMWA applications, with a special focus on the advances in general preparation strategies and microscopic structure construction. Furthermore, the current challenge and future prospect of 1D electromagnetic absorbers are proposed, which should provide some guidelines for the design of advanced EMWA materials.

show abstract

Selective synthesis and defects steering superior microwave absorption capabilities of hollow graphitic carbon nitride micro-polyhedrons

Cited by 53 publications

References 68 publications

In situ generated gas bubble-directed self-assembly of multifunctional MgO-based hybrid foams for highly efficient thermal conduction, microwave absorption, and self-cleaning

In situ generated gas bubble-directed self-assembly of multifunctional MgO-based hybrid foams for highly efficient thermal conduction, microwave absorption, and self-cleaning

π‐Conjugated In‐Plane Heterostructure Enables Long‐Lived Shallow Trapping in Graphitic Carbon Nitride for Increased Photocatalytic Hydrogen Generation

Recent Progress of One-Dimensional Nanomaterials for Microwave Absorption: A Review

Contact Info

Product

Resources

About