CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhuo Ma,Yihui Li,Zheng Li,Ziyin Liu,Xuepeng Wang,Yuan Tan,Xingkun Chen,Wei Lu,Yunjie Ding
Increasing dimethyl oxalate (DMO) hydrogenation activity remains a challenge. A Cu catalyst was designed by creating Cu nanoparticles (NPs) over SiO 2 layer formed on the CeO 2 particles (SiO 2 @CeO 2 ) using the ammonia evaporation method followed by the calcination and reduction step. The optimized 30Cu/SiO 2 @5CeO 2 catalyst shows good performance in the micro-packed bed reactor (100 % DMO conversion, 95.9 % ethylene glycol (EG) selectivity, 200 h stability) under the condition of the ratio of H 2 to DMO (H 2 /DMO) = 30, 190 °C and 2 MPa in the run, and CeO 2 was proved to be effective in the DMO hydrogenation process. The exposed CeO 2 on the surface of catalyst was found to facilitate the formation of Cu + by its interaction between adjacent Cu nanoparticles, resulting in the faster adsorption and dissociation of C=O bond on the catalyst surface, according to the characterization results obtained by the XRD, XPS and in situ FT-IR, etc.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WATER ENVIRONMENT RESEARCH
·
2021
·Vol. 93
·期 12
·2903-2913
·
IF 1.946
Pan Xiong,Siqi Fan,Jinshan Song,Qizhou Dai
In this study, a magnetic nanocatalyst (Fe 3 O 4 @SiO 2 @CeO 2 ) was prepared and applied in the catalytic ozonation of methyldopa (MD). The effects of operational parameters on catalytic ozonation performance were investigated, including ozone dosage, catalyst dosage, initial MD concentration, and pH. The removal of MD was 45.2% in ozonation, whereas the efficiency was achieved to 83.0% with the addition of Fe 3 O 4 @SiO 2 @CeO 2 . The results showed that Fe 3 O 4 @SiO 2 @CeO 2 could significantly improve the catalytic ozonation performance. And the enhanced mechanism study showed that it was attributed to promotion of ozone decomposition to generate hydroxyl radical. The reaction model was explored, and the reaction rates were calculated for the MD degradation in catalytic ozonation. A higher degradation efficiency of MD in catalytic ozonation was attributed to the enhanced surface effect of the catalysts, which was confirmed by using TBA, PO 4 3− , and p -BQ as scavengers of hydroxyl radical, surface reaction, and superoxide radical. The hydroxyl radical and superoxide radical played an important role in the degradation of MD. The mechanism of catalytic ozonation by Fe 3 O 4 @SiO 2 @CeO 2 was discussed via X-ray photoelectron spectroscopy (XPS) spectra and experimental data. Practitioner Points Fe 3 O 4 @SiO 2 @CeO 2 could promote the decomposition of ozone to produce hydroxyl radicals. High degradation efficiency of methyldopa with Fe 3 O 4 @SiO 2 @CeO 2 was achieved. A mechanism of catalytic ozonation with Fe 3 O 4 @SiO 2 @CeO 2 was proposed.
研究领域:
环境科学
·
化学工程
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2025
·
IF 4.7
Jiale Zhang,Xiaohu Qu,Jianhang Yin,Ning Wang
With the development of advanced electronic packaging, a big challenge for the chemical mechanical polishing (CMP) is to achieve the global planarization of EMC (epoxy molding compound)- Si -Cu materials with the normal ceramic abrasives. In this paper, the SiO 2 @CeO 2 core-shell composite abrasive is developed for the CMP of EMC/Si/Cu materials for the first time, and a global planarization with low removal selectivity is expected owing to the synergistic effect of the core-shell abrasives. Two sol-gel synthetic strategies, i.e., oil bath and ultrasonication, are proposed for the controllable synthesis of the SiO 2 @CeO 2 abrasives, which exhibit a good dispersive stability with a large absolute zeta potential >30 mV. The slurry for the CMP of EMC-Si-Cu based on the SiO 2 @CeO 2 abrasives shows the advantage in controlling the surface roughness, material removal rate and the removal selectivity. Especially, the ultrasonic SiO 2 @CeO 2 abrasives give rise to the low surface roughness (Cu 2 nm, Si 0.3 nm, EMC 10 nm) and the low removal selectivity (Cu/EMC/Si = 1.58:1.56:1.00). Therefore, the proposed SiO 2 @CeO 2 core-shell abrasives and the developed CMP slurry opens an alternative way for the planarization of EMC/Si/Cu materials in the advanced electronic packaging.
研究领域:
材料科学
·
电子封装技术
✓ 已验证
产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2013
·
IF 5.437
Liu Deng,Chaogui Chen,Chengzhou Zhu,Shaojun Dong,Hongmei Lu
In this paper, Graphene oxide@SiO 2 @CeO 2 hybrid nanosheets (GSCs) have been successfully synthesized by the wet-chemical strategy. TEM, FITR and XPS were applied to characterize the morphology and composition of the nanosheets. The colorimetric assay of these nanosheets indicated that they possessed high intrinsic peroxidase activity, which should be ascribed to the combination of graphene oxide and CeO 2 . A fully integrated reagentless bioactive paper based on GSCs was fabricated, which were able to simultaneously detect glucose, lactate, uric acid and cholesterol. The results demonstrated that GSCs have great potential as an alternative to the commonly employed peroxidase in daily nursing and general physical examination.
研究领域:
材料科学
·
医学诊断
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 52
·期 21
·12806-12817
·
IF 2.599
Zhong Xi,Zhou Yuming,He Man,Tong Yuan,Fan Lidan,Cai Zhilan
In this study, a simple, convenient and green approach for the preparation of organosiloxane-coated SiO 2 /CeO 2 (SiO 2 /CeO 2 /poly(VTMS)) with multilayered hierarchical structure is demonstrated by consecutive surface cerium deposition and organosiloxane grafting on the bare silica spheres. The results of the UV–Vis spectrum and photoluminescence analysis suggest that the fillers may be potentially applied in UV absorbers and bioimaging materials. Moreover, the optical diffusers based on the multilayered spheres can be prepared via a solvent-free UV curing process and exhibit enhanced properties like suitable light transmittance, good diffusion capacity and low-incident angle dependence, which are critical for the optical diffusers. In addition, when the concentration of the fillers was 15 wt%, the optical diffusers presented superior light-diffusing properties among all the as-prepared samples. Thus, the films based on the SiO 2 /CeO 2 /poly(VTMS) with multilayered hierarchical structure may open up new possibilities in applications as multifunctional light diffusion films in liquid crystal displays.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
·
2016
·
IF 4.055
M.M. Mikhailov,V.V. Neshchimenko,Chundong Li
This study carried out on the diffuse reflective spectra of zinc oxide modified by Al 2 O 3 , ZrO 2 , SiO 2 , CeO 2 , TiO 2 and Y 2 O 3 nanoparticles . It was established that during the modification are formed the solid solutions between zinc oxide and nanopowder as Al 2 ZnO 4 , ZrZnO 3 , Zn 2 SiO 4 , Ce x Zn (1−х) О y , Zn 2 TiO 4 , Y x Zn (1−x) O y . The diffuse reflection spectra of the modified powders are changed in the UV and visible range with a maximum at 395 nm. This band is determined by the intrinsic point defects in the crystal lattice of ZnO as interstitial zinc ions and zinc vacancy. In the IR region also recorded changes due to the absorption of OH-groups adsorbed on the surface modified zinc oxide.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
SURFACE AND INTERFACE ANALYSIS
·
2026
·
IF 2.7
Huiling Jia,Yuequan Jian,Jiayi Lv,Jinxiu Wu,Xiaoxiong Ma
The double-shell P (MMA-MPS)/SiO 2 /CeO 2 composite abrasive was designed and prepared through the soap-free emulsion polymerization, the sol–gel method, and the in situ chemical precipitation method. Take 3-(methacryloyloxy)propyltrimethoxysilane-modified methyl methacrylate (P (MMA-MPS)) microspheres as the core. The a SiO 2 and b SiO 2 inner shells were coated on the core in acidic and alkaline environments, respectively. The CeO 2 outer shell was then deposited on the inner shell. The morphology, structure, and chemical mechanical polishing performance on KDP crystals of composite abrasives were characterized using SEM, TEM, XRD, FTIR, XPS, and AFM. The results indicate that the P (MMA-MPS)/ a SiO 2 /CeO 2 abrasive possesses the “loose net-like” inner shell of a SiO 2 with the positive charge (-Si-OH 2 + ), leading to the sparser outer shell of CeO 2 and the expanded CeO 2 lattice. After polishing, the surface roughness (Ra) of KDP crystal is 0.69 nm, and the material removal rate (MRR) is 125.6 nm/min. The P (MMA-MPS)/ b SiO 2 /CeO 2 abrasive possesses the “dense strawberry-like” inner shell of b SiO 2 with the negative charge (-Si-O − ), which facilitates the uniform deposition of Ce 3+ through electrostatic adsorption, and forms the dense, complete and highly crystalline outer shell of CeO 2 . The proportion of Ce 3+ is increased by 2.5%. After polishing, the Ra of the KDP crystal further decreases to 0.43 nm, and the MRR increases to 146.2 nm/min. In summary, the comprehensive performance of the P (MMA-MPS)/ b SiO 2 /CeO 2 abrasive is superior to that of the P (MMA-MPS)/ a SiO 2 /CeO 2 abrasive.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Jiahao Liu,Xiaojie Jin,Xi Lu,Xinyu Huang,Hongyan Chen,Long Qiu,Xiaowei Huang,Yongxiu Li,Jing Li
The application of rare earth micro-nano materials requires first formulating them into slurries with high dispersion stability, including polishing powders, catalysts, phosphors, ceramics, and other materials. To achieve this, it is essential not only to prepare monodisperse micro-nano particles but also incorporate appropriate dispersants to prevent particle aggregation. For this purpose, the study designed and synthesized a core-shell structured Gd 3 + -doped CeO 2 -coated SiO 2 composite abrasive: SiO 2 /CeO 2 :Gd. Low-field nuclear magnetic resonance technique was employed to investigate the sedimentation behavior of polishing slurries and explore the mechanism by which different dispersants enhance slurry dispersion stability, achieving real-time nuclear magnetic resonance imaging tracking of the sedimentation process. Results show that: The strong paramagnetic properties of Gd 3+ significantly enhance the relaxation efficiency of water molecules within the particle surface region, thereby serving as a sensitive probe for characterizing the liquid environment at the particle surface. Based on the T 2 distributions, settling can be divided into three stages: homogenization, sedimentation, and agglomeration. In polishing slurries, water molecules primarily exist in three forms: bulk water (P1), hydration layer water (P4) and surface-bound water (P5), attributing to different peaks of T 2 relaxation times. However, only one T 2 peak (P2) was observed for the homogenization slurry due to the rapid exchange among the three kind of water molecules. With the sedimentation proceeding, P2 transforms into two peaks of P1 and P3. The rate of change in the peak areas of P1 and P2 can reflect the sedimentation rate of the slurry. In the agglomeration stage, the overlapping of hydration layers forms interstitial water, leading to an increase in its T 2 relaxation time. Therefore, the P3 can further split into two peaks of P4 and P5, corresponding to interstitial water and surface-bound water in the sediment layer.
研究领域:
材料科学
·
核磁共振（NMR）
·
化学机械抛光（CMP）
·
胶体与界面科学
·
纳米技术
✓ 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）