ACS Nano
·
2025
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IF 16
Hengdong Ren,Chensi Zhou,Ka Wang,Ximing Zhang,Lei Feng,Wenqing Wei,Yuqing Sun,Yukang Liu,Jun Dai,Xiaobing Xu,Zhiyong Zhang,Xinglong Wu
Interface polarization (one of the slow polarizations) is considered the primary mechanism driving microwave absorption (MA), but limitations in material composition and microstructure design often lead to weak interfacial polarization relaxation. In this work, we developed an interesting heterostructure consisting of carbon nanotube-encapsulated α-Fe2O3 nanocolumns (CNTs@α-Fe2O3). The curvature effects of CNTs induce a built-in electric field between CNTs and α-Fe2O3 nanocolumns, facilitating effective interface polarization. Under microwave irradiation, electron accumulation at the interfaces, driven by the energy-level mismatch between the two materials, further strengthens interface polarization, leading to a highly efficient MA performance. This heterostructured material achieves a minimum reflection loss of −74.1 dB at a thickness of 1.8 mm and an effective absorption bandwidth (reflection loss ≤ −10 dB) of 5.2 GHz (11.9 ∼ 17.1 GHz) at a thickness of only 1.5 mm. X-ray photoelectron spectroscopy and Raman scattering show a distinct blueshift in the Fe 2p binding energy and the A1g mode energy (exclusively associated with Fe atom vibrations), suggesting substantial charge transfer and redistribution at the interface associated with enhanced interface polarization. This work provides insights into interface polarization through the strategic design of energy levels and materials.
研究领域:
材料科学
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物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
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IF 21.1
Mazhar Khan,Zeeshan Akmal,Muhammad Tayyab,Seemal Mansoor,Dongni Liu,Ziwei Ye,Jinlong Zhang,Shiqun Wu,Lingzhi Wang
The rational design of heterojunction photocatalysts is crucial for enhancing CO 2 photoreduction efficiency, yet precisely channeling photogenerated electrons to the CO 2 adsorption sites remains an enormous challenge. In this work, we developed an organic-inorganic heterostructure with continuous inter- and intra-component electric fields. The integration of BiOBr with MIL-125 via chemical bonding established a heterojunction, where the built-in electric field between the two components facilitated the efficient transfer of photogenerated electrons from BiOBr to MIL-125. The intrinsic electric field of MIL-125 further drove the accumulation of photogenerated electrons at Ti sites. This tandem electric field effect, in conjunction with the CO 2 adsorption and activation at Ti sites, significantly enhanced the efficiency of CO 2 reduction within the heterojunction system. The optimized photocatalyst achieving CO production at a rate of 65.6 μmol g −1 h −1 with nearly 90 % selectivity without the use of sacrificial agents, exhibiting a remarkable 43-fold and 8-fold enhancement in activity compared to pristine MIL-125 and BiOBr, respectively. In-situ infrared spectroscopy and theoretical calculations confirmed the energy optimization effect of the heterostructure on CO 2 activation and the hydrogenation reaction, facilitating the formation of the key intermediate *COOH. This work elucidates the mechanism by which tandem built-in electric fields facilitate charge separation.
研究领域:
材料科学
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环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2024
·
IF 16.8
Hongyu Chen,Zengxuan Chen,Shoufu Cao,Zhaojie Wang,Xiaodong Chen,Xiaojing Lin,Qi Hou,Shuxian Wei,Siyuan Liu,Baojun Wei,Xiaoqing Lu
Nitrogen-doped carbon (NC) for carbon dioxide reduction reaction (CO 2 RR) are promising candidates. However, its selectivity and activity are limited by the undeveloped pore and limited electronic effect. Herein, we propose a strategy of three birds with one stone to utilize the embedded nickel for inducing electron-rich pyridinic-NC with multimodal porous structure based on the hard template assisted sacrificial template method. Nickel acts as sacrificial agent and inducer to facilitate the formation of mesoporous and reactive nitrogen species for capturing and activating reactants, respectively. Besides, we find that nickel as electron donor endows the NC with electron accumulation for participating actively in PCET reaction. The resultant Ni 0.87 -NC-1-AE exhibits an eminent FE CO of 97.6 % with excellent activity and stability. In-situ Raman spectroscopy and the projected crystal orbital Hamilton populations (pCOHP) confirm the accumulation of *COOH and the stable adsorption of *COOH on the surface. What’s more, the well-designed experiments and DFT calculations accurately locate pyridinic-N as the active site, where the aggregated electrons donated by nickel significantly reduce the energy barrier of rate-determining step and promote the desorption of CO. This work provides an instructive perspective to construct advanced NC electrocatalysts with high mass transfer efficiency and high catalytic activity.
研究领域:
材料科学
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电催化
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Jiamei Ma,Wei Zhong,Langlang You,Yi Pei,Chunxin Lu,Zhiyin Xiao,Zhongquan Shen,Xiujuan Jiang,Nianlong Qian,Xiaoming Liu,Shuhua Zhang
In this work, three materials of Cu-Cu 2 O/rGO-NH 2 -4.4/1, -1/1 and -1/10.4, in which the numeric suffices denote the ratio of Cu/Cu 2 O in the materials, were described and characterized using various analytical techniques including FTIR, XRD, SEM, HRTEM, XPS and Raman spectroscopy. To probe the band structures of these materials, UPS, cyclic voltammetry, and UV–vis reflection spectroscopy were also employed. The formation of heterojunctions in the ternary materials tune their band structures by raising the energy level of valence band maximums (VBMs), inducing an internal electric field (IEF) and an electron accumulation layer (EAL) within the materials. Augment of copper content in the materials can enhance the energy level rising. The coordination of N-methylimidazole (NMI) with Cu 2 O of the materials can also contribute to raising the energy level. The changes in these electronic properties bring about a synergistic effect in selective aerobic oxidation of benzylic alcohols via improving O 2 activation and facilitation of electron transfer between the catalyst and the reactants due to the rising of the energy level of VBM and the formation of IEF.
研究领域:
材料科学
·
催化
·
电化学
·
表面科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）