POLYMER DEGRADATION AND STABILITY
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2019
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IF 3.78
Tian Liu,Xingrong Zeng,Xuejun Lai,Hongqiang Li,Yanlin Wang
Organosilicon materials with high capacity of organic-to-inorganic conversion at elevated temperature are always favorable in the field of high-temperature-resistant materials, flame retardant materials, chemical engineering and functional materials in electrical engineering. In this work, it was found out that the platinum-nitrogen catalytic system could obviously enhance the organic-to-inorganic conversion efficiency of silicone rubber (SiR) at elevated temperature. The residual rate of Pt/N/SiR (SiR containing 0.33 phr Karstedt's catalyst (Pt) and 2 phr nitrogenous silane (N)) at 1000 °C was significantly improved from 3.0% to 44.8% in comparison with SiR and its thermal stability was also enhanced. DLS , TEM and UV–vis absorption spectrometry revealed that the platinum in Karstedt's catalyst would aggregate at elevated temperature and deteriorate its catalytic activity for organic-to-inorganic conversion of SiR. And the addition of nitrogenous silane can efficiently inhibit the aggregation and retain the high catalytic efficiency of platinum. A thorough TG-FTIR study, together with SEM/EDX and XPS analyses suggested that the platinum-nitrogen system might suppress the intramolecular cyclic transition and enhance the radical coupling between polymer chains of SiR during thermal degradation , which resulted in the high capacity of organic-to-inorganic conversion of Pt/N/SiR at elevated temperature.
研究领域:
材料科学
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化学工程
·
电气工程
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2019
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IF 3.131
Xuesheng Liu,Xueli Li,Xuewei Liu,Sisi He,Junsu Jin,Hong Meng
To improve the photocatalytic performance of ZnO nanoparticles , based on the collective effect as electron sink of Ag and perfect two-dimensional (2-D) feature of graphene, Ag-ZnO-rGO nanoparticles were prepared by polyvinyl alcohol assisted freeze-drying and subsequent hydrothermal reduction method. Through photocatalytic degradation of methyl orange solution under UV irradiation , all as-prepared samples were assessed and compared with those of published works. The surface morphology , microstructure and optical property of materials were systematically studied by XRD , XPS , SEM , TEM and DRS , respectively. XPS and Raman spectra results confirmed that GO has successfully been reduced to rGO; SEM and TEM characterizations manifested that Ag-ZnO NPs were uniformly distributed in rGO with two-dimensional sheets structure; DRS characterization and Kubelka-Munk formula calculation illustrated that Ag-ZnO-rGO exhibited the smallest band gap and the best optical absorption performance. Moreover, the photocatalytic degradation results indicated that Ag-ZnO-rGO NPs combine the advantages of graphene and Ag which not only has significant adsorption but also maintains high photoreactivity.
研究领域:
材料科学
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环境科学
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纳米技术
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
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IF 16.744
Yunning Chen,Renquan Guan,Xueying Cheng,Jie Zhao,Zhengkai Wu,Yan Wang,Qingkun Shang,Yingnan Sun
In this paper, two surface oxygen vacancy-rich TiO 2 composite photocatalysts were successfully constructed by solid thermal reduction ((R-Vo)TiO 2 ) and bimetallic doping (Nd-Fe-(D-Vo)TiO 2 ). The oxygen vacancies were characterized in detail using XPS, Raman, EPR and STEM. The results show that the excellent photocatalytic performance of Nd-Fe-(D-Vo)TiO 2 deriving from its doping energy and surface oxygen vacancies. Nd-Fe-(D-Vo)TiO 2 could degrade 58 % of phenol within 120 min, which was much greater than 15 % of TiO 2 and 27 % of (R-Vo)TiO 2 . Three composite photocatalysts, TiO 2 @EA, (R-Vo)TiO 2 @EA and Nd-Fe-(D-Vo) TiO 2 @EA, with better visible light absorption and photocatalytic performance were further obtained by bonding ellagic acid (EA) to the surface of TiO 2 . Nd-Fe-(D-Vo)TiO 2 @EA could almost completely degrade ethinyl estradiol within 20 min with a high minimization degree of 84 %. The possible sites of ethinyl estradiol attacked by free radicals were predicted by theoretical calculation combining with high-resolution mass spectrometry analysis, and the possible degradation mechanism was proposed.
研究领域:
环境科学
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材料科学
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化学工程
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光化学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2021
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IF 6.953
Lingyuan Chen,Jiali Tang,Xinyue Zhang,Shixing Wang,Zhaogang Ren
A novel benzothiazole modified chitosan ( BCS ) with excellent Au(III) adsorption performance and selectivity was prepared as adsorbents. The structure and morphology of the adsorbents were characterized by FTIR, SEM, XRD and XPS. The adsorption property of the adsorbents for Au(III) were investigated under different reaction time, initial concentration of Au(III), temperature, pH and coexisting ions. The maximum adsorption capacity of BCS for Au(III) was 1072.22 mg/g at 298 K and optimal pH = 4, which was better than that of other adsorbents reported in literature. The adsorption kinetics and isotherm models fit the pseudo-second-order and Langmuir equations. This shows that the adsorption process of Au(III) is a monolayer chemical adsorption. The adsorption process can proceed spontaneously and belong to the endothermic reaction according to the thermodynamic results. The excellent adsorption performance is mainly attributed to the ion exchange and chelation of the nitrogen, sulfur and oxygen groups on the adsorbent with gold ions. Significantly, BCS has excellent selectivity toward Au(III) and remarkable recycle performance. With the high adsorption capacity, excellent selectivity and outstanding reusability, the BCS adsorbent could be a promising candidate to adsorb Au(III) from wastewater.
研究领域:
材料科学
·
环境化学
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分析化学
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产品关联
DOI
PubMed
高影响因子
Biomass Conversion and Biorefinery
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2022
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IF 4.05
Xiao Yaoxin,Zhang Jun,Zhu Lingjun,Shan Rui,Yuan Haoran,Chen Yong
A series of inexpensive electroplating sludge-derived magnetic copper-containing catalysts were developed for the selective hydrogenation of biomass-based furfural (FFR) into furfuryl alcohol (FA) and 2-methylfuran (MF). The specific structural characteristics of as-prepared magnetic copper-containing samples were clearly identified through various techniques, including XRD, XPS, N 2 adsorption–desorption, NH 3 -TPD, SEM and so on. The characterizations revealed that the hydrogen pre-activated magnetic catalysts supplied metallic Cu species, medium acidity and porosity for the catalytic upgrading of FFR in hydrogen atmosphere. As for FFR-to-FA as well as FFR-to-MF transformations, the magnetic copper-containing catalyst with calcination temperature of 800 °C exhibited excellent performance towards the formation of FA and MF, wherein desirable FA yield of 98.5 mol% and MF yield of 71.3 mol% were achieved at reaction temperatures of 160 °C and 240 °C, respectively. The reuse experiments indicated that the recycled catalysts still maintained excellent activity and stability even after four-time recycling. The present study thus highlights a new approach for the resource utilization of electroplating sludge, which also supplies low-cost and efficient catalytic materials for the selective upgrading of various biomass-derived platform molecules.
研究领域:
催化
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化学工程
·
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2022
·
IF 13.7
Zhuyang Chen,Chen Xu,Fu Zhao,Shibo Xi,Weixuan Li,Mingcheng Huang,Bijun Cai,Meng Gu,Hsing-Lin Wang,X.-D. Xiang
A combinatorial high-throughput aerogel synthesis method is developed to systematically study the synergistic catalytic effects of multiple non-noble metal elements. A large number of aerogels with different compositions were synthesized and the corresponding ternary phase diagrams of the composition–electrocatalytic performance were constructed. A batch of aerogel catalysts with outstanding catalytic performance and stability for the electrochemical oxygen evolution reaction (OER) were discovered. Amorphous Fe3Co3Ni2-(oxy)hydroxide with excellent electrocatalytic performance (Tafel slope of 49 mV dec–1 and η100 of 421.48 ± 6.41 mV) was found to achieve a mass activity of 611.23 A/gmetal at 1.63 V (vs RHE). X-ray photoemission spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) studies reveal that the incorporation of a third atom (Ni and Ce) into the binary aerogels enlarges the Co–O atomic distance and reduces the average valence state of Co, which in turn speed up the oxygen evolution reaction kinetics. This work puts forward a strategy for high-throughput synthesis and screening of electrocatalysts and provides valuable data sets for future machine learning and prediction of high-performance electrocatalysts.
研究领域:
材料科学
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电化学
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催化
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2022
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IF 10.319
Yue Liu,Feng Peng,Guang-Ling Yang,Zhi-Hui Xie,Wenxin Dai,Yuejun Ouyang,Liang Wu,Chuan-Jian Zhong
The utilization of photoelectrochemical cathodic protection (PECCP) enables an indirect corrosion protection of metals with low self-corrosion potential by introducing a metallic nickel interlayer. However, the ability to enhance the PECCP efficiency remains challenging because of the inherent property of the semiconductor. Herein, this ability is demonstrated by coupling a covalent organic framework (TpBD) decorated TiO 2 photoanode (TiO 2 /TpBD) with nickel coating on magnesium alloy for an effective corrosion protection. The composite photoanode showed direct PECCP for the nickel interlayer and indirect corrosion protection of the magnesium alloy. The composite structure of the nanotube array and the covalent organic framework for the photoanode were confirmed by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The enhanced photoelectrochemical conversion capability and PECCP performance of the nickel-coated Mg alloy were evidenced by the results from electrochemical and photoelectrochemical measurements including Mott-Schottky curves, photoinduced potential variations, and electrochemical impedance spectroscopy (EIS). Lastly, a corrosion protection mechanism is proposed, where the enhanced PECCP efficiency is attributed to the formation of a direct Z-scheme heterojunction, which is substantiated by the results from valence band (VB) XPS and electron spin resonance characterizations.
研究领域:
材料科学
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电化学
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腐蚀科学
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光电化学
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
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2019
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IF 6.669
Chaofan Zheng,Huaili Zheng,Yongjun Sun,Bincheng Xu,Yili Wang,Xinyu Zheng,Yongjuan Wang
Poly(4-vinyl pyridine) decorated magnetic chitosan biopolymer (VMCP), as an absorbent and reductant, was prepared and used to remove hexavalent chromium (Cr(VI)) from aqueous solution. Compared with undecorated magnetic biopolymer, VMCP exhibited significantly improved removal performance under identical experimental conditions. The kinetics, isotherms, and thermodynamics of Cr(VI) adsorption onto VMCP were investigated. Results demonstrated that the maximum monolayer adsorption capacity of VMCP was 344.83 mg/g, which was considerably higher than most reported adsorbents. The mechanism for Cr(VI) removal was explored based on XPS and FTIR analyses. The main mechanisms were concluded to be Cr(VI) adsorption onto the positively charged VMCP surface and the reduction of Cr(VI) to Cr(III), followed by coordination between Cr(III) and N atoms. The easy regeneration, satisfactory reusability, and remarkable performance in column tests revealed the high potential of VMCP in treating Cr(VI)-contaminated water.
研究领域:
环境科学
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材料科学
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化学工程
·
水处理
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DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
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IF 3.5
Yanxue Yue,Weiyu Zhu,Alhadi Ishag,Bo Zhang,Yubing Sun
The natural clay mineral was activated using the acid treatment under ultrasonic conditions to improve its adsorption performance. The acid-activated clay (AAC) was investigated to remove Cr(VI) from wasted lubricant and U(VI) from aqueous solution by batch, spectroscopy, and modeling. Batch experiments showed that the isotherms and adsorption kinetics of Cr(VI)/U(VI) on AAC were satisfactorily followed by Frenudlich and the pseudo-second-order model, respectively. The decreased adsorption of U(VI) on AAC with the increase of ion strength indicated the outer surface complexation of U(VI) on AAC. The interaction mechanism of Cr(VI)/U(VI) on AAC was demonstrated to be surface complexation by oxygenated functional groups (e.g., hydroxyl) according to X-ray photoelectron spectroscopy (XPS) analysis. According to fitting of surface complexation models using three approaches, the adsorption of U(VI) on AAC at different pH can be better fitted by the double-layer model compared to the constant-capacitance model and triple-layer model. These findings are great important for the application of acid activated clay in the removal of heavy metals and radionuclides from the environment.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2025
·
IF 8.3
Luoming Kang,Bin Jiang,Xiaoming Xiao,Longfei Zhang,Xiaodong Yang,Na Yang,Yongli Sun,Luhong Zhang
Liquid organic hydrogen carrier (LOHC) systems require efficient, low-cost catalysts for scalable hydrogen storage. Here, a reusable CoNi bimetallic catalyst was developed through one-step reductive pyrolysis of ZIF-67-L, forming CoNi alloy nanoparticles embedded in a 3D carbon nanosheet/nanotube (CNS/CNT) heterostructure. Using N-ethylcarbazole (NEC) as a model compound, the optimized catalyst enables rapid hydrogenation (5.72 wt% H 2 uptake at 150 °C, 8 MPa in 80 min) and dehydrogenation (5.64 wt% H 2 release at 220 °C, 0.1 MPa), with high recyclability over seven cycles. The CNS/CNT facilitates electron transport, enhances active site exposure, and provides a high surface area. Combined XPS and DFT results reveal that the synergy between the CNS/CNT architecture and CoNi alloying modulates the electronic environment of Co 0 sites, reduces the energy barrier for H 2 dissociation, and improves catalytic performance. This study provides new insights into the design of highly active and stable non-noble metal catalysts for LOHC systems to achieve reversible hydrogen storage.
研究领域:
材料科学
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能源存储
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纳米技术
·
催化
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2025
·
IF 4.2
Lijie Sun,Jianlei Guo,Bo Li
In laser-driven inertial confinement fusion (ICF) facities, sol-gel derived silica antireflective films have been widely prepared on optical components to improve the laser transmission performance. Current researches indicate that long-term exposure of final optical assemblies in high-power laser systems can lead to the degradation of anti-pollution performance, directly affecting the high-flux output of the laser facities. However, the underlying mechanisms remain unclear. Therefore, we conducted a multiscale investigation combining macroscopic wettability analysis with nanoscale structural characterization. Contact angle measurements demonstrated a systematic hydrophilicity shift ( Δ θ > 50 ° ) accompanied by a 139 % increase in surface free energy following gamma irradiation. High-resolution surface metrology via white light interferometry (WLI) confirmed roughness stability across irradiation doses up to 1000 kGy , while scanning electron microscopy (SEM) imaging revealed stochastic crack formation. Crucially, controlled experiments on geometrically ideal substrates established that such nanoscale topographical defects contribute minimally to wettability alterations, decisively shifting focus to chemical modification mechanisms. X-ray photoelectron spectroscopy (XPS) analysis revealed a notable decrease in relative carbon content from 18.96 % to 14.85 % as radiation dose increased from 0 kGy to 1000 kGy . Combined with the observation that hydrophobicity in non-irradiated samples primarily originates from surface-grafted hydrophobic groups (-CH 3 ), this confirms radiation-induced degradation of hydrophobic moieties as the key mechanism driving the hydrophobic-to-hydrophilic transition. This work elucidates the physicochemical mechanisms of surface contamination of the optical components in high-power laser systems, providing theoretical foundations for optimizing radiation resistance in antireflective films.
研究领域:
材料科学
·
光学
·
核工程
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表面化学
·
薄膜材料
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2025
·
IF 5.7
Ying Li,Huaping Xiong,Wei Shi,Zheming Ni,Shengjie Xia
Defect engineering and heterostructure construction are important strategies to enhance the photocatalytic performance of single-phase materials. In this study, an O- and Cd-dual-defect-modified LaOCl@CdS heterojunction (Ov-L@Cdv-C) was successfully constructed. Under visible light irradiation, using the typical fluoroquinolone antibiotic ciprofloxacin (CIP) as the target pollutant, Ov-L@Cdv-C exhibited superior photocatalytic degradation performance compared to Ov-LaOCl and Ov-L@CdS. Under optimal conditions (0.5 g/L catalyst, 0.010 g/L initial CIP concentration, pH = 5), the degradation efficiency of CIP reached 84.79 % within 150 min, significantly higher than that of Ov-LaOCl (48.73 %) and Ov-L@CdS (71.96 %). XPS and EPR characterizations confirmed the presence of abundant O and Cd dual defects in the Ov-L@Cdv-C heterojunction. ESR and free radical quenching experiments revealed that the main reactive species during the degradation process were ·O 2 − and h⁺. Based on work function calculations and built-in electric field analysis, a Z-scheme photocatalytic mechanism for the Ov-L@Cdv-C dual-defect heterojunction was proposed. Furthermore, LC-MS analysis identified the degradation intermediates and proposed three possible degradation pathways. In addition, T.E.S.T. predictions indicated that the toxicity of CIP gradually decreased during the photocatalytic degradation process.
研究领域:
环境科学
·
催化
·
材料科学
·
化学工程
·
光化学
·
分析化学
·
毒理学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）