ChemCatChem
·
2020
·Vol. 12
·期 13
·3512-3522
·
IF 4.853
Chunlei Zhang,Guojuan Liu,Ping Wu,Gaofeng Zeng,Yuhan Sun
Graphical Formaldehyde oxidation : Complete HCHO removal was achieved at 90 °C under demanding conditions over the interconnected 3D structure of Na 1.1 Mn 4 O 8 -nanosheet@ Mn 5 O 8 -nanorod biphasic-crystals. Structure defects on the nano-rod/-sheet shared-edges significantly enhance the activity. With the increasing concerns on the formaldehyde (HCHO) hazard, the efficient oxidation of HCHO over affordable and harmless catalyst is of significant practical interest. Herein, the intermediate state of Mn 5 O 8 −Na 1.1 Mn 4 O 8 (Na−Mn 5 O 8 ) biphasic-crystal catalyst, which features Na 1.1 Mn 4 O 8 -nanosheet@ Mn 5 O 8 -nanorod interconnected 3D structure, is successfully fabricated through the anaerobic calcination of manganite followed by alkali treatment. The resultant Na−Mn 5 O 8 exhibits 100 % conversion of HCHO (150 ppm and 60000 h −1 ) and reliable stability (50 h) at 90 °C under demanding water-free feed conditions, which is superior to that of the reference samples of Mn 5 O 8 , Na 1.1 Mn 4 O 8 , MnO 2 and Na−MnO 2 . The experimental results demonstrate that the abundant structure defects (oxygen vacancies) on Na−Mn 5 O 8 , which may locate along the phase interfaces / shared-edges of Mn 5 O 8 nanorods and Na 1.1 Mn 4 O 8 nanosheets, significantly enhance the active oxygen species and finally contribute to the high activity for HCHO oxidation. Furthermore, the 3D structure of Na−Mn 5 O 8 favors mass transfer and fully exposing active sites for the HCHO adsorption and conversion. These findings reveal a way to enhance the catalytic activity of metal oxides via controlling the intermediate state of heteropical crystals.
研究领域:
材料科学
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环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Hao Li,Manling Zhang,Yufeng Jiang,Yi Liu,Wenjun Duan,Di Lang,Wei Du,Zhaofeng Chang,Peng Zhang,Bo Pan
s Biochar exhibited excellent performance in activating persulfate (PS) for the degradation of organic contaminants. However, the role of endogenous metals in the activation of PS needs to be clarified, which will hinder the understanding of the PS activation mechanism by biochar and the design of efficient biochar for PS activation. In this study, biochars were prepared at different temperatures using cellulose, and trace amounts of Fe (0.069 %) and Mn (0.056 %) were incorporated separately or together into biochar to mimic the endogenous metals whose concentrations were consistent with the ones in local corn stalks. Our results demonstrated that a trace amount of Fe could greatly enhance the removal of ofloxacin (OFL) in the C1000-Fe system. Removing metals from biochar via acid-washing did not significantly impact the removal efficiency of OFL. The Raman analysis showed that Fe could increase the defect structures in C1000-Fe, which were converted during the cycling experiments, indicating they participated in the activation of PS. ROS capturing and quenching experiments confirmed that the increased defect structures via Fe in C1000-Fe facilitate the activation of PS to generate superoxide anions (O 2 •− ) and then convert them into singlet oxygen ( 1 O 2 ) for OFL degradation. Our results highlighted that a trace amount of Fe in biochar enhanced its activation of PS for degradation of OFL via altering the carbon structure, not itself as the activation site, which will benefit understanding the role of endogenous metals in the activation of PS.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Xiaokun Zhu,Xin Gu,Jiamei Han,Jiabin Jiang,Zimeng Pan,Jiachen Wang,Zihao Chen,Xiang Liu
Facile-prepared films with a high-temperature coefficient of resistivity ( TCR ) are crucial for application in high-sensitivity bolometers. In this study, La 0.7 Ca 0.25 K 0.05 MnO 3 (LCKMO) films were grown on (001)-oriented La 0.3 Sr 0.7 Al 0.65 Ta 0.35 O 3 (LSAT) substrates using the spin-coating method. Various sintering temperatures (900 °C ≤ T s ≤ 1050 °C) were utilized in the film preparation, causing the lattice mismatch between films and substrate degraded. The effect of T s on the strain state of films was investigated through X-ray diffraction (XRD) analysis. The distortion of MnO 6 octahedra and the Mn–O bond were assessed using Raman and FTIR spectra, respectively. The structural perfection and elemental valence of films were adjusted via optimizing T s . Meanwhile, the strain state and defect structure were effectively improved with T s increasing. These results indicate that the LCKMO films with high crystalline quality can be achieved by optimizing the sintering process. The TCR of LCKMO films was modified. When T s at 1000 °C, the LCKMO films exhibit the remarkable TCR of 16.29% K -1 at 269.54 K, indicating the substantial potential of LCKMO films in infrared bolometers.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2024
·
IF 4.2
Z.H.A.O.-X.U.A.N. Jiang
In this investigation, UiO-66-NH 2 was effectively synthesized through a solvothermal approach, utilizing benzoic acid and hydrochloric acid (HCl) as modulating agents. This synthesis process intentionally introduced defects mediated by benzoic acid, and the degree of these defects was precisely adjusted by the concentration of HCl. Subsequently, the material underwent a covalent modification process through an amidation reaction, resulting in the attachment of tetrakis (4-carboxyphenyl) porphyrin (TCPP). The results demonstrated a significant improvement in the photocatalytic reduction of Cr(VI), showcasing a 125 % elevation in reduction efficiency as compared to the unmodified UiO-66-NH 2 material serving as the baseline. The performance enhancement is due to the synergistic effect of the defect structure and TCPP modification, which enhances the light absorption, promotes charge transfer and separation, reduces the recombination rate, and improves the adsorption capacity and light absorption efficiency of Cr(VI). This research introduces an innovative approach and a highly effective catalyst, offering a novel solution for modifying metal-organic frameworks (MOFs) and enhancing their photocatalytic performance in the reduction of Cr(VI).
研究领域:
材料科学
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环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SYNTHETIC METALS
·
2021
·
IF 3.266
Siqin Jia,Qiguan Wang,Jian Chen,Sumin Wang
Carbon doped metallic compounds have attracted a great deal of interest due to their new synergistic properties and enhanced catalytic performance from the doped-element induced defects. In this paper, polyaniline (PANI) is used as the carbon source to dope molybdenum carbide , which is annealed at 1000 °C to be nitrogen-doped carbon coupled with Mo 2 C (NC@Mo 2 C). Through the XRD , SEM and TEM methods the prepared NC@Mo 2 C composite is thoroughly characterized. The NC@Mo 2 C composite illustrates two-dimensional nanoplate morphology, and shows low overpotential in hydrogen evolution reaction (HER, 0.04 V) and oxygen evolution reaction (OER, 0.13 V) in 1 M KOH solution. Tafel slopes of NC@Mo 2 C for HER and OER are 100 mV decade −1 and 99 mV decade −1 , respectively, rather lower than pure Mo 2 C (HER: 130 mV decade −1 and OER: 126 mV decade −1 ). The Raman and XPS results show that it is the structural defects of Mo 2 C derived from NC doping that activate the reaction. Meanwhile, the NC doping and resulted defects enhance the conductivity of Mo 2 C, as well as endow NC@Mo 2 C nanoplates high electrochemical active surface area, facilitating the ion transfer, water absorption and gas desorption. The results of our work open up a new chance to design efficient non-noble metal-based catalysts for water electrolysis.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Energy Materials
·
2019
·Vol. 9
·期 35
·1901313
·
IF 24.884
Ruixiang Ge,Lei Li,Jianwei Su,Yichao Lin,Ziqi Tian,Liang Chen
Developing efficient and durable electrocatalysts for the oxygen evolution reaction (OER) in acidic media is attractive but still challenging. In this study, ultrafine defective RuO 2 nanoparticles are successfully prepared on carbon cloth by means of dip-coating, annealing, and acid etching. As a self-supported electrocatalyst, it exhibits an ultralow overpotential of 179 mV in 0.5 m H 2 SO 4 . More importantly, the high activity can be well maintained for 20 h. The density functional calculations revealed that the defect can not only increase the number of active sites but also improve the intrinsic OER activity.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Xiaowen Huo,Yingying Zhao,Zhaojing Jing,Jian Wang,Haitao Wang,Na Chang
One of the main approaches to improve the permeability of membranes is the preparation of PA layers with nanostructures based on metal organic framework (MOF) materials. However, the interaction between MOF additives and PIP/TMC monomers and the mechanisms affecting the interfacial polymerization process have not been elucidated. In this study, the adsorption conformation between the two-phase monomers and UiO-66 (UiO-66-TFA) was established by density functional theory (DFT) calculations based on Lewis acid-base theory. The results showed that the hydrogen bonding force between UiO-66 (UiO-66-TFA) with defect structures and PIP (−199.62 kcal/mol) was significantly stronger than that between UiO-66-TFA and TMC (−26.39 kcal/mol). Moreover, two PA layers with ridged and granular morphologies were prepared by dispersing UiO-66/UiO-66-TFA in the water/organic phase to influence interfacial polymerization, using UiO-66-TFA nanoparticles as additives. Among them, the PA layers showed more pronounced morphological transformation and excellent separation properties when UiO-66-TFA was used as an additive in the aqueous phase . The representative ridge-like nanostructured nanofiltration membrane showed a pure water flux of 27.51 L·m −2 ·h −1 and 98.8 % retention of Na 2 SO 4 . This study provides a new idea for the preparation of PA layers with different surface nanostructures based on the IP reaction of nano-additives.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Mengna Shi,Tie Ma,Chenqi Wang,Changcheng Liu,Que Huang,Li Guo,Dan Li
The thermal stability of lithiated graphite plays an important role in the thermal safety of lithium-ion batteries (LIBs). However, a safer graphite anode usually leads to a lower energy density. This article starts from multiple hazardous factors of lithiated graphite when thermal runaway occurs, considering the impact of defects on the electrochemical performance and thermal safety of graphite electrodes. In this study, turbostratic graphite was prepared as the anode for LIBs. The stacking of graphite was altered to form narrow pores and spherical aggregates, and introducing defects. By varying the ball-milling time, the structural changes of different ball-milled graphites were analyzed. The impact mechanism of defect structure on electrode electrochemical performance and safety performance was investigated. The results show that the spherical structure and large specific surface area are beneficial to increase the active sites and delay the self-heating of the battery. The formation of defects and pores increases the adsorption sites, which makes the surface adsorption of Li + dominant and improves the ion diffusion. In addition, the dominance of surface adsorption and desorption effectively suppresses the problem of graphite flake peeling and intensified thermal runaway caused by graphite phase transition and lithium evolution heat release at high temperature. The thermal safety test was carried out by accelerated calorimeter (ARC), and its thermodynamics and reaction kinetics were quantitatively analyzed. It was proved that the introduction of surface adsorption lithium storage method successfully delayed the thermal runaway of the battery, realizing the balance between high electrochemical performance and high safety.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2025
·
IF 5.5
Jin Li,Zhujun Chen,Xin Li,Bingshuang Li,Pengxuan Wu,Xiaoxi Huang
Indium sulfide-based electrocatalysts often suffer from the reduction of In3+ to In0 species in the electrocatalytic CO2 reduction reaction (CO2RR), and this dynamic transformation leads to undesired hydrogen evolution reaction. Promoting the stability of high-valent In3+ species under operating conditions is a challenging but important task for maintaining their excellent electrocatalytic activity. In this work, In2S3 electrocatalysts with controllable crystallinity are synthesized by a hydrothermal reaction at a tunable temperature. The low-crystalline In2S3-1 exhibits more abundant defective and amorphous/crystalline interface structures compared with the high-crystalline ones, thus endowing the low-crystalline In2S3-1 with a higher formate faradaic efficiency (FEformate) of 91.6% at −1.45 V vs RHE in the H-type cell compared with the high-crystalline In2S3-3 (FEformate = 79.3%). This improved electrocatalytic activity can be attributed to its abundant defect structures and amorphous/crystalline interface structures with robustly high-valent In3+ species under the operating conditions. In situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy results reveal the *OCHO reaction pathway. Density functional theory (DFT) calculations indicate that defective structures, such as sulfur vacancies, play an important role in lowering the energy barrier for the key intermediate *OCHO formation. This work provides important insight into defect engineering to promote CO2RR.
研究领域:
材料科学
·
电化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Xiaoyu Shi,Xiaodong Zhang,Fukun Bi,Zenghui Zheng,Lijun Sheng,Jingcheng Xu,Zhong Wang,Yiqiong Yang
In this thesis, defective UiO-66-NH 2 using cetyltrimethylammonium bromide (CTAB) as a template was successfully synthesized. The toluene adsorption-desorption properties were studied using breakthrough experiments and temperature programmed desorption (TPD). Modified UiO-66-NH 2 showed a high toluene increase due to the increased specific surface area and total pore volume and extra accessible adsorption sites generated by defects. Additionally, adsorption mechanisms were discussed at micro and molecule levels in light of density functional theory (DFT) calculations. By calculation, the amino hydrogen bonding gave rise to a higher toluene adsorption over UiO-66-NH 2 . In terms of the modified UiO-66-NH 2 with the most deficiencies, synergistic effects among π-π, -NH 2 , OH-CH 3 and OH-π hydrogen bonding strength also significantly intensified toluene adsorption. Furthermore, it could be noted that the OH-π interaction was stronger than the two bonded μ 3 -OH mechanisms. Notably, TPD and binding energies (BEs) depicted that defective UiO-66-NH 2 had a weaker toluene affinity than did UiO-66-NH 2 . Thus, gas toluene was easy to desorb with defective UiO-66-NH 2 at 298 K under atmospheric pressure. Finally, the repetitive regeneration experiment showed that the reproducibility of the materials was excellent.
研究领域:
材料科学
·
环境科学
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Tianyi Xu,Dongxu Jiao,Lei Zhang,Haiyan Zhang,Lirong Zheng,David J. Singh,Jingxiang Zhao,Weitao Zheng,Xiaoqiang Cui
Development of efficient electrocatalysts requires construction of catalytic surfaces with moderate H adsorption energy. Here, we address this challenge by Br-induced formation of P-poor defective nickel phosphide and show that the H adsorption energy can be optimized by regulating the vacancy concentration. We show that when such defective Ni 12 P 5−x Br x nanoparticles are distributed on the surface of Ni 2 P nanosheets (Ni 12 P 5−x Br x /Ni 2 P NS), excellent catalytic activity for water splitting is obtained in alkaline media. Density functional theory computations revealed that Br doping induce the formation of a P-poor nickel phosphide with vacancies, leading to an optimal H adsorption strength with a volcano-type relationship. This is the best reported for a non-precious metal phosphide at present: the overpotential for HER is 18 mV at 10 mA cm −2 and 155 mV for OER. This leads to an exceptionally low cell voltage requirement of only 1.44 V to drive overall water splitting in an alkaline electrolyzer.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Haojie Zhao,Beili Yi,Xiaomeng Si,Wenda Bao,Lei Cao,Longxing Su,Yanli Wang,Lien-Yang Chou,Jin Xie
Metal–organic frameworks (MOFs), a new type of porous material, have shown many possible applications in gas storage and separation, biomedicine, catalysis, and so on. While most MOFs are synthesized through solvothermal synthesis where a large quantity of organic solvent is used, the green synthetic approach using a minimized amount of solvent is important to prevent irreversible environmental compacts. In this study, we successfully synthesized Zr-MOFs with SBUs (e.g., UiO-66 and MIL-140A) using a simple metal source and investigated the role of organic modulators in modulating the MOF structures during solid-state synthesis. Meanwhile, UiO-66 rich in defects synthesized via a solid-state conversion strategy shows good catalytic performance for the ring-opening of epoxides with alcohols. This work contributes to the understanding of the role of organic modulators in the solid-state synthesis of MOFs.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）