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
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催化化学
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产品关联
DOI
高影响因子
Materials
·
2018
·Vol. 11
·期 6
·995
·
IF 2.467
Anquan Deng,Yufu Zhu,Xin Guo,Lei Zhou,Qingsong Jiang
TiO2micro-/nano-structures with different morphologies have been successfully synthesized via a hydrothermal method. The effects of the solvents on the morphology and structure of the obtained products have been studied. The objective of the present paper is to compare the photocatalytic properties of the obtained TiO2products. During the synthesis process, the tetrabutyl titanate and titanium (IV) fluoride were used as the titanium source. The obtained micro-/nano-structures were characterized by field-emission scanning electron microscopy, X-ray diffraction analysis, and nitrogen adsorption-desorption isotherms. The photocatalytic activity of the samples was evaluated by the degradation of Rhodamine B solution under simulated solar irradiation. It is found that the morphologies and structures of TiO2have a great influence on its photocatalytic activity. Compared with other samples, TiO2flower clusters assembled with nanorods exhibited a superior photocatalytic activity in the degradation of Rhodamine B.Keywords:TiO2;different morphologies;photocatalytic activity;formation mechanisms
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2019
·
IF 4.182
Hai-Tao Wang,Ya-Pan Liu,Hao Zhang,Na Chang,Wei Shao,Meng-Shan Shi,De Ao,Mei-Chan Lu
With the regular structures composed of metal clusters and organic ligands, metal-organic frameworks (MOFs) are expected to be the competent stabilizing matrix for nanoparticles and the excellent precursor of metal oxide with carbon species by means of high temperature pyrolysis , resulting to porous architectures with unexpected adsorptive or catalytic properties. Herein, we design and propose a facile route for preparing porous Carbon doped ZnO/TiO 2 @ZIF-8 (C–ZnO/TiO 2 @ZIF-8) multi-component nano-platform using TiO 2 coated ZIF-8 as precursor and template followed by thermal calcination . The resulted C–ZnO/TiO 2 @ZIF-8 nanocrystal simultaneously possesses original ZIF-8 morphology and porous structure with connected ZnO nanoparticles. As a result, C–ZnO/TiO 2 @ZIF-8 shows obviously better adsorption affinity towards methylene blue (MB). Moreover, benefit from the TiO 2 coating outside ZIF-8 matrix, escape of carbon species which originate from pyrolysis of organic ligands is efficiently inhibited, with the resulted materials doped with abundant carbon. Therefore, charge transfer and isolation of the resulted catalyst are promoted accordingly, with catalytic activity of the prepared C–ZnO/TiO 2 @ZIF-8 multi-component photocatalyst significantly increased by 1.8-fold and 3.0-fold compared to ZnO@ZIF-8 photocatalyst under irradiation of UV and visible light, respectively.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Sustainability
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2021
·
IF 4.524
D. Zheng,C. Lv,X. Zhang,S. Chen,H. Liu,Y. Sun,X. She,D. Li,D. Yang
Developing cost-effective electrocatalysts with efficient activity and superior stability for hydrogen evolution reaction (HER) over a wide pH range is highly desirable and remains a significant challenge. Herein, we report CoP supported RuP 3 nanosheet (RuP 3 –CoP NS) HER electrocatalysts through an ice-templating method. Constructing heterojunctions of RuP 3 and CoP can reduce the loading of scarce Ru species in the catalyst, and meanwhile, maintain efficient HER activity over a wide pH range. The RuP 3 –CoP NS catalyst with only about 15 wt.% loading of Ru species exhibits remarkable HER performance with excellent catalytic stability and low overpotentials of 25, 60, and 81 mV at 10 mA/cm 2 in alkaline, acidic, and neutral media, respectively. The density functional theory calculations indicated that the RuP 3 could induce boosting the catalytic activity of P sites in CoP. The enhancement of the HER performance can be attributed to the electron transfer from RuP 3 to the P sites in CoP, which changes its electronic structure, and thus, optimizing the adsorption strength of H ∗ .
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2013
·
IF 2.145
Wei-guo Pan,Jie-nan Hong,Rui-tang Guo,Wen-long Zhen,Hong-lei Ding,Qiang Jin,Cheng-gang Ding,Shi-yi Guo
MnO x –CuO x /TiO 2 and MnO x –CuO x /Al 2 O 3 catalysts were prepared by sol–gel method and used for low temperature selective catalytic reduction of NO with NH 3 . The results showed that MnO x –CuO x /TiO 2 had better catalytic activity and SO 2 resistance than MnO x –CuO x /Al 2 O 3 in the temperature range of 100–250 °C. The properties of the catalysts were characterized by using XRD, N 2 adsorption, temperature programmed reduction (H 2 -TPR) and temperature programmed desorption (NH 3 -TPD). It was found that the support has a great impact on the acidity of catalyst; TiO 2 and Al 2 O 3 can promote the formation of Lewis acid sites and Brönsted acid sites respectively.
研究领域:
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
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2014
·Vol. 90
·期 5
·947-954
·
IF 2.494
Yunfang Chen,Jianzhang Fang,Shaoyou Lu,Weicheng Xu,Zhang Liu,Xiaoxin Xu,Zhanqiang Fang
BACKGROUND Chlorophenols (CPs) are organic pollutants and are most widespread in the aqueous environment. Photocatalytic degradation of organic compounds has been extensively studied as a potential technology for water treatment. In this study, BiOI/Bi 2 WO 6 hierarchical heterostructure with flower-like morphology was synthesized by a facile method using a one-step hydrothermal approach. The catalytic activities of the photocatalysts were tested by the degradation of 2,4-DCP under visible-light irradiation and the photocatalysis mechanism of BiOI/Bi 2 WO 6 was investigated. RESULTS The as-prepared catalysts exhibited the characteristic peaks of BiOI and Bi 2 WO 6 . The photocatalytic activities, which were evaluated by degradation of 2,4-DCP under visible light irradiation, were enhanced significantly by BiOI/Bi 2 WO 6 hierarchical heterostructures with different molar ratios of BiOI to Bi 2 WO 6 . CONCLUSIONS BiOI/Bi 2 WO 6 hierarchical heterostructure significantly enhanced the photocatalytic activity. The optimum percentage of BiOI was 10%. The optimal initial pH value of 2,4-DCP was determined to be pH 8. The possible reaction mechanisms were discussed on the basis of the calculated energy band positions. © 2014 Society of Chemical Industry
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Sustainable Materials and Technologies
·
2022
·
IF 10.681
Boshu Jiang,Qiming Sun,Bachirou Guene Lougou,Hao Zhang,Xian Li,Zhibin Qu,Yong Shuai,Chi-Hwa Wang
The solar-driven thermochemical CO 2 conversion is an effective way to achieve the mission of carbon peaking and carbon neutrality . However, finding a material with excellent thermal stability, oxygen exchange capacity, and CO selectivity is one of the most important challenges in the thermochemical CO 2 conversion approach. This study investigated the solar thermochemical CO 2 -splitting characteristics through the synergistic thermal catalytic activity of CuO and NiFe 2 O 4 and the effect of SiC photothermal properties. The thermochemical redox cycling performance of CO 2 conversion through thermally activated catalysts was experimentally investigated via thermogravimetric combined quantum chemical calculations to provide comprehensive insights into the physicochemical principles underlying the thermochemical catalytic CO 2 -splitting. The X-ray diffraction, scanning electron microscopy, and energy spectrum detector technics were developed to gain detail on the crystal structure, surface morphology , and chemical composition changes in the reacting media. The newly synthesized composite material consisting of 25%CuO and 75%NiFe 2 O 4 (CNF-13) coated SiC porous skeleton resulted in higher CO 2 -splitting catalytic activity with an instantaneous CO production of 10.98mL ⋅ min ‐1 g CNF‐13 −1 and direct CO 2 -to-CO conversion rate of 33.9% at 1000–1200 K reaction temperature. The thermochemical CO 2 -splitting activity and redox stability of CNF-13@SiC was promoted by the photothermal properties of SiC support and the formation of Cu 2 O and Fe 3 O 4 new active material phases easing CO 2 reduction at low energy. This study provided experimental and theoretical findings that can be used as guidance for the fundamental research and application of CO 2 catalytic conversion into fuels through a solar thermochemical driven strategy.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
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2022
·
IF 9.794
Hengyi Chen,Minghao Hu,Peng Jing,Baocang Liu,Rui Gao,Jun Zhang
Transition metal disulfides (TMD) are considered as promising catalysts for hydrogen evolution reaction (HER) due to their unique structural and electronic properties. However, as a representative, the tungsten disulfide (WS 2 ) shows an insufficient HER performance and is still needed to be further improved. Herein, we report the synthesis of CeO 2 -modified WS 2 nanosheets with abundant heterostructures on carbon cloth (CeO 2 /WS 2 /CC) as an efficient self-supported integral electrode for HER. Experimental results and theoretical calculations imply that the intimate electronic interaction between CeO 2 and WS 2 promotes the production of more oxygen vacancies in CeO 2 to regulate the electronic structure of WS 2 , endowing extra active sites, high electron transfer efficiency, and downshifted d-band center of W, which can lead to thermoneutral hydrogen adsorption Gibbs free energies (ΔG H* ) and thus boosts HER. The optimized CeO 2 /WS 2 /CC electrode displays an improved HER performance with an overpotential of 128 mV at 10 mA cm −2 in 0.5 M H 2 SO 4 aqueous solution, 87 mV smaller than that of the WS 2 /CC electrode. Meanwhile, it also could maintain a 20 h of stable HER activity. Our work provides an effective approach to achieve various hybrid catalysts of rare earth compounds-transition metal compounds with highly active sites for superior electrocatalysis .
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
BIOTECHNOLOGY LETTERS
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2021
·Vol. 43
·期 8
·1617-1624
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IF 2.461
Wang Liuzhu,Jiang Shuiqin,Sun Yangyang,Yang Zeyu,Chen Zhi,Wang Hualei,Wei Dongzhi
Objectives Catalytic promiscuity, or the ability to catalyze a secondary reaction, provides new opportunities for industrial biocatalysis by expanding the range of biocatalytic reactions. Some nitrilases converting nitriles to amides, referred to as the secondary activity, show great potential for amides production. And our goal was exploiting the amide-forming potential of nitrilases. Results In this study, we characterized and altered the secondary activity of nitrilase from Acidovorax facilis 72 W (Nit72W) towards different substrates. We increased the secondary activity of Nit72W towards 2-cyanopyridine by 196-fold and created activity toward benzonitrile and p-nitrophenylacetonitrile by modifying the active pocket. Surprisingly, the best mutant, W188M, completely converted 250 mM 2-cyanopyridine to more than 98% 2-picolinamide in 12 h with a specific activity of 90 U/mg and showed potential for industrial applications. Conclusions Nit72W was modified to increase its secondary activity for the amides production, especially 2-picolinamide.
研究领域:
生物化学
·
工业生物技术
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DOI
PubMed
高影响因子
ACTA PHYSICO-CHIMICA SINICA
·
2017
·Vol. 33
·期 7
·1462-1473
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IF 0.767
HUANG Xue-Hui,SHANG Xiao-Hui,NIU Peng-Ju
Mesoporous SBA-15 with mesopore diameter up to 10.1 nm was prepared by a hydrothermal method, and was further functionalized to obtain different surface properties. Thus-prepared SBA-15 was employed as a template to synthesize rhombohedrally crystallized mesoporous La0.8Sr0.2CoO3
perovskite via a nanocasting method. The surface properties of the SBA-15 were adjusted by treatment with concentrated hydrochloric acid, trimethylchlorosilane (TMCS), and 3-aminopropyltriethoxysilane (APTES). A series of characterization techniques verified that all the synthesized
templates possessed ordered two-dimensional hexagonal mesoporous structure, and the surface was successfully modified with methyl and amino groups. The mesoporous perovskite structure was formed in the samples and the surface properties of SBA-15 significantly influenced the structure and
properties of La0.8Sr0.2CoO3 perovskite oxides. Wide-angle X-ray diffraction patterns suggested that the modified silica templates were conducive to the formation of pure perovskite frameworks with good crystallinity. The catalysts also possessed mesoporous
structure, as confirmed by small-angle XRD patterns, high-resolution transmission electron microscopy images, and nitrogen adsorption analysis. Moreover, the La0.8Sr0.2CoO3 materials synthesized using surface-functionalized templates exhibited relatively higher
catalytic activity and stability in CO oxidation. Complete CO conversion could be achieved at 140°C #xb0;Cusing the thus-prepared La0.8Sr0.2CoO3 materials, and no significant loss in catalytic activity was observed after 100 h of on-stream reaction experiments.
X-ray photoelectron spectroscopy, H2 temperature-programmed reduction, and O2 temperature-programmed desorption experiments revealed that the existence of Co4+, Sr enrichment in the perovskite structure, and high content of adsorbed oxygen species play a critical
role in the enhanced catalytic activity of the catalysts. We also proposed the possible reasons for the effect of surface properties of the silica templates on the structure and properties of the La0.8Sr0.2CoO3 nanomaterials.
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2016
·
IF 3.299
Meichao Gao,Dafeng Zhang,Xipeng Pu,Hong Li,Wenzhi Li,Xin Shao,Dongdong Lv,Bingbing Zhang,Jianmin Dou
Fe-doped BiOCl photocatalysts were synthesized by a simple combustion method. The as-synthesized catalysts were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy and UV–Vis diffuse reflectance spectroscopy. Fe 3+ doping leads to red-shift in the absorption band and increased visible light absorption. The photocatalytic reaction tests in the degradation of the dyes of rhodamine showed that the doping of Fe 3+ could bring about a big increase in the photocatalytic activity under visible light irradiation. The main reactive oxygen species and photocatalytic mechanism of Fe-doped BiOCl under visible light irradiation were discussed in detail.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2012
·Vol. 18
·期 51
·16491-16497
·
IF 5.925
Fan Qin,Guangfang Li,Runming Wang,Jiliang Wu,Hongzhe Sun,Rong Chen
Graphical Uniform Bi 2 O 3 and (BiO) 2 CO 3 nanotubes were synthesized by a solvothermal method without involving any surfactants or templates. The synergistic effect of ethylene glycol and urea played a critical role in the formation of the tubular structure. The Bi 2 O 3 and (BiO) 2 CO 3 nanostructures not only exhibited excellent Cr VI -removal capacity, but also displayed high photocatalytic efficiency for the degradation of Rhodaine B under visible-light irradiation (see figure). Uniform bismuth oxide (Bi 2 O 3 ) and bismuth subcarbonate ((BiO) 2 CO 3 ) nanotubes were successfully synthesized by a facile solvothermal method without the need for any surfactants or templates. The synergistic effect of ethylene glycol (EG) and urea played a critical role in the formation of the tubular nanostructures. These Bi 2 O 3 and (BiO) 2 CO 3 nanotubes exhibited excellent Cr VI -removal capacity. Bi 2 O 3 nanotubes, with a maximum Cr VI -removal capacity of 79 mg g −1 , possessed high removal ability in a wide range of pH values (3–11). Moreover, Bi 2 O 3 and (BiO) 2 CO 3 nanotubes also displayed highly efficient photocatalytic activity for the degradation of RhB under visible-light irradiation. This work not only demonstrates a new and facile route for the fabrication of Bi 2 O 3 and (BiO) 2 CO 3 nanotubes, but also provides new promising adsorbents for the removal of heavy-metal ions and potential photocatalysts for environmental remediation.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
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