International Journal of Applied Ceramic Technology
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2021
·Vol. 19
·期 2
·729-738
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IF 1.968
Xiao Ma,Zhifeng Huang,Hailong Yuan,Xiangyu Lu,Yujuan Zhou,Qiang Shen,Fei Chen
The traditional model for wLEDs usually encapsulates the phosphor and resin mixture on the InGaN blue-emitting chip. However, the poor thermal stability of silicone resin will lead to the reduction of the luminescent intensity of the wLED devices. Glass has excellent thermal stability and transparency, which is a promising alternative to resins. In this work, Ce-doped silicate luminescent glasses have been developed by a high-temperature melting quenching method in air atmosphere. The luminescent intensity can be enhanced by increasing the heat treatment temperature and extending the heat treatment time in 10%H 2 /Ar atmosphere because Ce 4+ ions can be reduced to Ce 3+ ions. However, when the heat treatment temperature reaches 850°C, the generation of precipitates in the glass can reduce the luminescent intensity. The transmittance of glass can reach 87%, and the highest luminous intensity obtained when heat treated at 800°C. The glass transition temperature is 740°C and the thermal conductivity of the glass is .95 W m −1 K −1 , which is about five times higher than that of resin. The results show that the emerging Ce-doped silicate luminescent glass could be the potential material for wLED applications.
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JOURNAL OF HAZARDOUS MATERIALS
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2020
·
IF 9.038
Jingyu Ren,Jie Li,Lei Lv,Jian Wang
Herein, Ce doped CoOOH was used as the catalyst for caffeic acid (CA) degradation by dielectric barrier discharge (DBD) plasma. The treatment performance and catalytic mechanism were studied by a series of experiments and density functional theory (DFT) simulations. The results show that the doping amounts of Ce significantly influenced the catalytic performance of CoOOH in DBD plasma, and the catalytic effect reached maximum when the molar ratio of Ce to Co was 1:9. CA was 100 % degraded by Ce 1 /Co 9 OOH/DBD with 10 min treatment, while only 75.6 % of CA was degraded by 10 min DBD treatment. Transformation of O 3 and H 2 O 2 to ⋅OH was mainly responsible for the catalytic effect. The content of oxygen vacancies and unsaturated Co (Lewis acid sites) of CoOOH was increased by doping Ce according to the results of experiments and simulations, and the change was conducive to the catalytic reactions. DFT simulations also indicated that DBD generated O 3 and H 2 O 2 were decomposed to O atoms, OH groups and free OH by Ce/CoOOH. The presence of reductive species in DBD plasma was confirmed, and ⋅H was a kind of important reactive specie for CA degradation. CA degradation pathway was proposed based on the detected degradation products.
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2020
·
IF 16.683
Lixia Li,Juanhua Kong,Huimin Zhang,Sijie Liu,Qiang Zeng,Yaqin Zhang,Hao Ma,Hongyan He,Jinxing Long,Xuehui Li
The catalytic depolymerization process for lignin to produce value added chemicals is often challenged by the limited mass transfer over heterogeneous catalysts, the complex aromatic biopolymer structures, and the high recalcitrance of C C bonds. Herein, a series of hierarchical MFI nanosheets (MFI-ns) supported metal oxide catalysts have been designed and used for the selectively oxidative cleavage of organosolv lignin. As expected, 81.6 % conversion of lignin can be achieved over 15Ce-5Cu/MFI-ns with 294.0 mg g −1 yield of volatile products, including 180.9 mg g −1 of diethyl maleate. Quantum chemistry calculation coupled with static adsorption measurements shows that the superior catalytic activities of these catalysts are ascribed to the favorable mass transport of lignin to the active sites by the unique layer structure, and the hierarchical pore sizes distribution, as well as the electronic effect between Cu and Ce components. In addition, the catalytic mechanism for the cleavage of C C bonds in β -O-4 model probes has been studied via the controlled oxidative degree of model compounds and the isotope-labeling experiments. Therefore, this work provides a new insight into the efficient utilization of lignin via the rational design of catalysts.
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CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Xiaoqiang Wang,Yue Liu,Zhongbiao Wu
In this paper, the Cu-Ce based catalyst using NbOPO 4 (Nb-P) as support was firstly employed for selective catalytic reduction (SCR) of NO by NH 3 . The experimental results had illustrated that such catalyst exhibited well SCR activity and N 2 selectivity within a wide temperature range of 200–450 °C. These superior performances could be mainly attributed to its improved textural properties and strong acidity derived from NbOPO 4 support. More importantly, the sulfur tolerance of the NbOPO 4 supported Cu-Ce sample was found greatly improved compared to TiO 2 and Ti-Nb supported samples, where above 80% SCR activity of Cu-Ce/Nb-P sample was obtained at 250 °C after 10 h reaction running in the presence of 100 ppm SO 2 . This fact was the result of the enhanced acidity and the strong interactions between Cu-Ce oxides and NbOPO 4 support, which could prevent the surface oxygen species from sulfation by SO 2 . As such, these oxygen species strongly associated with NbOPO 4 support still could activate adsorbed NH 3 to fulfill the SCR reaction cycle, leading to its better sulfur resistance. The work would provide some enlightenments to the development of NH 3 -SCR catalysts with high sulfur resistance at medium-high temperature.
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JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Xidong Wang,Li Xu,Luhan Wang,Shuyang Bao,Yu Wang,Qianxiong Wen,Yanrong Liang,Zhaopin Chen,Xiaoli Fang,Weidong Xiang
As an inorganic color conversion material, phosphor-in-glass film (PiF) has received extensive attention in the sphere of laser-driven white lighting due to its excellent integrated performance. The yellow-emitting phosphor La 3 Si 6 N 11 :Ce has excellent thermal stability and wide emission band, which makes it more competitive than Y 3 Al 5 O 12 :Ce in laser-driven white lighting. Herein, we embedded La 3 Si 6 N 11 :Ce phosphor powder in a silicate glass matrix (SiO 2 –B 2 O 3 –CaO–Na 2 O) and sintered it on a sapphire substrate. In the silica-rich glass system, the network structure of silica-oxygen tetrahedral glass is more rigid and the thermal erosion of the phosphor by the silica-based glass is less, which makes the phosphor maintain better performance after low-temperature co-sintering. The quantum efficiency in the optimized LSN phosphor-in-glass film (LSN PiF) is up to 81 %, and the thermal conductivity is 10.2 Wm −1 K −1 , showing good thermal stability. Impressively, the LSN PiF produces a bright near-white light (0.3323,0.346) at a blue laser of 5.6 W, with corresponding luminous efficiency up to 195 lm/W. Moreover, LSN PiF can maintain about 80 % of the initial luminous intensity after continuous lighting for 24 h at the incident power of 3.5 W. These outstanding properties can advance the development of LSN phosphors in high power laser lighting applications.
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JOURNAL OF HAZARDOUS MATERIALS
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2023
·
IF 13.6
Jiangyan Song,Yongyi Yu,Xiaoshuai Han,Weisen Yang,Wenbin Pan,Shaoju Jian,Gaigai Duan,Shaohua Jiang,Jiapeng Hu
Herein, we used a one-pot method to fabricate a novel MOF-on-MOF adsorbent, namely MOF(Zr)-on-MOF(Ce). The adsorbent demonstrated a high maximum fluoride-ions capture capacity of 164.47 mg g −1 . The morphology, elemental distribution, pore size distribution, and thermal stability were studied using SEM-EDS, XRD , BET, and TGA . The influence of the temperature, solution pH, fluoride concentration, and coexisting ions was explored using intermittent experiments. The results suggested that MOF(Zr)-on-MOF(Ce) had a fast capture rate for fluoride. MOF(Zr)-on-MOF(Ce) maintained an excellent fluoride removal performance over a wide pH range with an initial fluoride concentration of 20 mg L −1 . The optimal effect was obtained at a pH of 4, but a high removal efficiency of 94% was maintained even at a pH of 9. Interference experiments showed that only the PO 4 3– had an adverse inhibition influence. The field experiments demonstrated that MOF(Zr)-on-MOF(Ce) can keep the safety threshold levels of fluoride in drinking water . The Langmuir and pseudo-second order kinetic models were well fitted for the defluoridation process, demonstrating that the adsorption of fluoride ions on MOF(Zr)-on-MOF(Ce) was dominated by monolayer chemisorption . With the further characterization and kinetic thermodynamic studies indicates that the removal mechanism involves ion exchange, electrostatic interactions and complexation effect.
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Journal of Water Process Engineering
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2023
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IF 7
Jiaqi Wei,Yuanyuan Zhang,Jinxing Ma,Shanshan Wang,Minmin Jiang,Qiaoyan Wei,Mei Chen,Xiaowu Huang,Haixiang Li,Xuehong Zhang,Junjian Zheng
Degradation of refractory organics has been limited by their low mass-transport rates in conventional flow-by operated electrochemical reactors. This study explores for the first time the development of porous titanium (Ti)-based metal oxide anodic membrane for efficient flow-through degradation of recalcitrant tetrabromobisphenol A (TBBPA). For this purpose, a duplexed Ti/SnO 2 -Sb/PbO 2 -Ce anodic membrane was successfully prepared by sol-gel and electrodeposition methods. Ti/SnO 2 -Sb/PbO 2 -Ce exhibited improved mechanical and electrochemical stability, larger electrochemical surface area, higher oxygen evolution potential and lower charge transfer resistance, as compared to its mono-layered rival (Ti/SnO 2 -Sb). The switching from flow-by to flow-through operation resulted in an increased mass transfer rate constant and narrowed diffusion layer thickness of Ti/SnO 2 -Sb/PbO 2 -Ce. In the flow-through mode, Ti/SnO 2 -Sb/PbO 2 -Ce enabled the complete TBBPA removal at a relatively low electric energy (0.11 kWh m −3 ). The TBBPA removal was ascribed to the direct anodic oxidation and indirect anodic oxidation incurred by absorbed HO , free HO and 1 O 2 . The intermediate products, which were arisen from the attack of TBBPA by these reactive species, were identified. We further estimated their acute toxicities and bioaccumulation factors. This research proposed a robust electrochemical filtration approach for detoxification of TBBPA-contaminated water.
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CHEMICAL ENGINEERING JOURNAL
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2023
·
IF 15.1
Hui Zhao,Haoyu Yao,Feifei Zhao,Liangrong Yang,Lianying Wu,Xiangfeng Liang,Huizhou Liu,Changjiang Yu
Efficient separation of rare earth elements (REEs) from leaching tailings is necessary for environmental protection and full utilization of resources. Cell walls are rich in various active groups that can efficiently adsorb REEs. In this work, a series of composite aerogels based on pectin and cellulose (the key active components in cell walls) were fabricated for effective adsorption of Ce (III) from leaching tailings. Physical and chemical properties of composite aerogels were characterized by Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), contact angle measuring, and a zeta potentiometer. Adsorption capacity was measured under different conditions. Adsorption corresponded to the Langmuir model and the maximum adsorption capacity of Ce (III) was 337.36 mg/g. Kinetic fitting showed that the adsorption process corresponds to the second-order kinetic model. Composite aerogels have excellent regeneration performance. The adsorption process occurred by electrostatic interaction, ion exchange with –COO − , and chelation with C-NH 2 . Adsorption in a sample of leaching tailings showed that the adsorption efficiency of composite aerogels for Ce (III) and Eu (III) reached 68% and 81%, respectively, demonstrating good practicability.
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CHEMICAL GEOLOGY
·
2023
·
IF 3.9
Tao Wu,Yujie Hong,Dongchen Shao,Jiatong Zhao,Zhengye Feng
The impact of the diffuse double-layer on the diffusion of radionuclide anions remains unclear, impeding the application of Archie's law for adsorptive anions. Through-diffusion experiments were carried out to measure the effective diffusion coefficient and distribution coefficient of Ce(III) in the presence of EDTA. A multi-porosity model, in combination with Archie's law, was used to estimate the effective diffusion coefficient. The predominant species, CeEDTA − , exhibited an effective diffusion coefficient of (0.88–1.92) × 10 −11 m 2 /s and the distribution coefficient of (0.81–1.18) × 10 −3 m 3 /kg at the compacted dry density of 1300–1800 kg/m 3 . The accessible porosity, the diffuse double-layer porosity, and the interlayer porosity were analyzed using the multi-porosity model, based on the characterization of bentonite via Scanning electron microscopy with energy dispersive spectrometry, X-ray diffractometer , and Nitrogen-Brunner-Emmett-Teller method. Due to the low external surface area of Zhisin bentonite (27.7–35.3 m 2 /g), the impact of the diffuse double-layer was insignificant on the total and accessible porosities. Additionally, the diffuse double-layer porosity had insignificant impact on the effective diffusion coefficient of CeEDTA − in compacted bentonite, as its value was one order magnitude lower than that of the interlayer porosity and the accessible porosity.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
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IF 9.9
Yueming Yan,Qian Zhu,Lei Cao,Feng Gu,Shiji Liu,Yuhao Luo,Feng Liu,Shufen Wang,Lanlan Fan,Shixian Xiong
Rational construction of efficient carbon-supported rare earth cerium nanoclusters as oxygen reduction reaction (ORR) is of great significance to promote the practical application of zinc-air batteries (ZABs). Herein, N doped conductive carbon black anchored CeO 2 nanoclusters (CeO 2 Clusters/NC) for the ORR is reported. The volatile cerium species vaporized by CeO 2 nanoclusters at high temperatures are captured by nitrogen-rich carbon carriers to form highly dispersed Ce-N x active sites. Benefiting from the coupling effect between oxygen vacancies-enriched CeO 2 nanoclusters and highly dispersed Ce-N x sites, the prepared 2CeO 2 Clusters/NC catalyst possesses an ORR half-wave potential of 0.88 V, superior electrochemical stability, and better methanol tolerance compared to commercial Pt/C catalysts. Moreover, the 2CeO 2 Clusters/NC involved liquid ZABs show excellent energy efficiency, superior stability, and a high energy density of 982 Wh kg −1 at 10 mA cm −2 .
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高影响因子
FUEL
·
2023
·
IF 7.4
Xin Guo,Zhiyong Ding,Na Kang,Liu Yang,Yuanjiang Wang,Cheng Zhang,Zhaoqiang Li,Tiantian Zhang,Yan Wang,Yu Wang,Hao Qu
The zeolite-based catalyst is a promising option for the selective catalytic reduction (SCR) of nitrogen oxides (NO x ) due to its low toxicity. However, the challenge lies in its low-temperature activity. This study developed a multi-component catalytic system consisting of Ce/Mn/Cu-loaded Beta zeolite to reduce NO x . With fixed contents of Cu and Mn, we investigated the NH 3 -SCR process and the mechanism of action of the rare-earth species (i.e., Ce) in the system. Upon optimization of the content of Ce, the Ce/Mn/Cu-loaded Beta zeolite demonstrated enhanced low-temperature activity compared to samples loaded with Cu or Cu/Mn in the temperature range of 150–250 °C. When Ce was loaded in an appropriate proportion, it regulated the oxidation state of Cu, optimizing active adsorption species for NO and strengthening the strength of Brønsted acid sites in the catalyst. These synergetic effects led to improved NH 3 -SCR catalytic performance. This study can contribute to a better understanding of multiple metal-loaded zeolites in the NH 3 -SCR process and inform future design of Beta-type catalysts.
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CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Xuan Wang,Zhenkuang Lei,Chunlin Zheng,Xueheng Zhuang,Qikui Man,Guoguo Tan
Semiconductor metal oxides are widely used in the field of wave absorption because of their easily tunable dielectric properties . Doping or modulating the morphology has been demonstrated to be an effective method to improve the microwave (MW) absorbing performance of semiconductor metal oxides. In this study, Ce-doped SnO 2 was prepared by a simple and effective coprecipitation method. Single-crystal SnO 2 nanorods were generated during the doping process and the size of the nanorods could be controlled by modifying the concentration of Ce. The presence of nanorods greatly enhances the MW absorbing performance: when the doping molar ratio is 3%, the minimum reflection loss of the absorber is −77.91 dB at a frequency of 13.79 GHz with a thickness of 1.6 mm and the maximum effective absorbing bandwidth is 4.47 GHz at a thickness of 1.5 mm. Excellent MW absorbing performance of Ce-doped SnO 2 is attributed to its excellent impedance matching and interfacial polarization.
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