CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Keke Yuan,Daoyang Han,Wanyu Zhao,Weiwei Zhang,Guiqin You,Mingliang Li,Bingbing Fan,Hongxia Lu,Hailong Wang,Hongliang Xu,Gang Shao,Rui Zhang
In the present work, polymer-derived SiCN ceramic aerogels (PDCA-SiCN) were fabricated via a combined sol-gel/freeze drying/polymer precursor conversion method. The microstructure of PDCA-SiCN was studied by regulating the synthesis temperature and time during the sol-gel process. PDCA-SiCN showed a unique three-dimensional network structure, and the specific surface area and pore size of PDCA-SiCN prepared at 150 °C for 20 h were 134 g/m 2 and 18 nm, respectively. To assess the electromagnetic wave absorption (EMA) properties of PDCA-SiCN, the materials were uniformly blended with common paraffin, and the influence of PDCA-SiCN/paraffin ratio on the EMA properties was also investigated. The sample with a PDCA-SiCN/paraffin ratio of 20:80 exhibited the best EMA performance, with a minimum reflection loss (RL) of −43.37 dB at 7.6 GHz and electromagnetic absorption bandwidth of 3.8 GHz, which correspond to an absorption of 99.99 % of the electromagnetic waves. The excellent EMA properties of PDCA-SiCN could be attributed to a synergistic effects of good impedance matching, multiple reflections and high dielectric loss.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Zhengyan Zhang,Zhi Teng,Xingwei Li
A good support is essential for the activity and durability of the supported catalysts. In this work, nitrogen-doped carbon with fluffy structure and high content of pyridinic-N and pyrrolic-N is prepared by the pyrolysis of polyaniline/ITO composite, which is conducive to uniform and firm loading of Pt catalysts. Herein, polyaniline is used as carbon and nitrogen sources, and ITO is used as a pyrolysis auxiliary due to the reaction of polyaniline dopant (proton acid) and ITO during the pyrolysis. Pt catalyst supported on above optimal support shows an excellent electrocatalytic performance for the methanol oxidation reaction, especially its stability, achieving an activity retention rate of 89.3% after 1000 cycles of cyclic voltammetry in 0.5 M H 2 SO 4 and 0.5 M CH 3 OH solution. This work provides a new strategy for preparing Pt-based catalyst with a high activity and a good durability.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 18
·22806-22817
·
IF 3.056
Li Jie,Yu Guangwei,Pan Lanjia,Li Chunxing,You Futian,Wang Yin
Antibiotics residues in aqueous environment and sewage sludge accumulation have become serious environmental issues. The aim of this study is to investigate the potential of ciprofloxacin (CIP) removal by sludge-based biochar prepared from co-pyrolysis of sewage sludge and bamboo waste (BW). The stability and environmental risk of heavy metals (HMs) in the biochar were further investigated to evaluate potential risks for biochar utilization. Results showed that BW was an outstanding additive to prepare co-pyrolyzed biochar from sludge. A higher CIP removal rate (95%) of BW-sludge biochar (SBC) was obtained under initial CIP concentration of 10 mg/L, and its maximum adsorption capacity was 62.48 mg/g which was calculated from the Langmuir model. The pseudo-second-order and Freundlich model also well fit the CIP adsorption process, indicating a chemical and multilayer adsorption of CIP on a heterogeneous surface of biochar. Adsorption mechanism analysis indicated that the diverse functional groups and Fe species in biochar probably were the dominant factors in the adsorption of CIP. The π-π interaction, H–bond, ion exchange, and Fe-complexation might be the main interactions between the functional species and CIP molecules. Besides, HMs, especially the Cr, Cd, and As, were well immobilized in SBC compared with pure sludge biochar. This work suggested that sludge-based biochar, especially the co-pyrolyzed SBC, could be a potential adsorbent for CIP removal from aqueous solutions.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-11
·
IF 12.121
Gao Shaojie,Hao Shaoyun,Huang Zhennan,Yuan Yifei,Han Song,Lei Lecheng,Zhang Xingwang,Shahbazian-Yassar Reza,Lu Jun
High-entropy alloy nanoparticles (HEA-NPs) are important class of materials with significant technological potential. However, the strategies for synthesizing uniformly dispersed HEA-NPs on granular supports such as carbon materials, γ-Al 2 O 3 , and zeolite, which is vital to their practical applications, are largely unexplored. Herein, we present a fast moving bed pyrolysis strategy to immobilize HEA-NPs on granular supports with a narrow size distribution of 2 nm up to denary (MnCoNiCuRhPdSnIrPtAu) HEA-NPs at 923 K. Fast moving bed pyrolysis strategy ensures the mixed metal precursors rapidly and simultaneously pyrolyzed at high temperatures, resulting in nuclei with a small size. The representative quinary (FeCoPdIrPt) HEA-NPs exhibit high stability (150 h) toward hydrogen evolution reaction with high mass activity, which is 26 times higher than the commercial Pt/C at an overpotential of 100 mV. Our strategy provides an improved methodology for synthesizing HEA-NPs on various supports.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2020
·
IF 3.905
Kai Li,Bo Wang,Dana Bolatibieke,Dong-Hong Nan,Zhen-Xi Zhang,Min-Shu Cui,Qiang Lu
Levoglucosenone (LGO) is a valuable chiral synthon and can be produced from pyrolysis of cellulose and biomass. In the present study, Ni-P-MCM-41 catalysts with various P-to-Ni ratios were prepared and employed for selective production of LGO from biomass. Both analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale experiments were conducted to explore the effects of several factors on the formation of LGO, including P-to-Ni ratio in Ni-P-MCM-41, catalyst/sample ratio and pyrolysis temperature. The results revealed that all the Ni-P-MCM-41 catalysts, especially the one with a P-to-Ni ratio of 5, exhibited excellent catalytic capability and selectivity for LGO production. For Py-GC/MS, the maximal LGO yields of 27.34 wt% and 14.30 wt% were achieved from cellulose and pine at 350 °C with catalyst/cellulose ratio of 3 and catalyst/pine ratio of 2, respectively. While in lab-scale experiments, the highest LGO yields from cellulose and pine were 21.37 wt% and 10.71 wt%, with the corresponding selectivity of 78.31% and 53.75%, respectively. The Ni-P-MCM-41 catalyst possessed much better catalytic efficiency on the LGO production than previously reported catalysts, including H 2 SO 4 , H 3 PO 4 , solid superacid, solid phosphoric acid and activated carbon.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 15
·18412-18422
·
IF 3.056
Hameed Rashida,Lei Cheng,Lin Daohui
Biochar (BC) colloids attract increasing interest due to their unique environmental behavior and potential risks. However, the interaction between BC colloids and organic contaminants that may affect their fates in the environment has not been substantially studied. Herein, adsorption and desorption of phenanthrene (PHN), atrazine (ATZ), and oxytetracycline (OTC) by a series of BC colloids derived from bulk rice straw BC samples with 6 pyrolysis temperatures (200–700 °C), and 3 particle sizes (250 nm, 500 nm, and 1 μm) were investigated. Regardless of pyrolysis temperature, BC colloids from a given sized bulk BC had a comparable size, being 30 ± 6, 70 ± 18, and 140 ± 15 nm corresponding to the three sized bulk BCs, respectively. The adsorption kinetics curves were well explained by the pseudo-second-order model, and pore diffusion was the primary rate-determining step. Both Freundlich and Langmuir models well fitted the adsorption isotherms. With increasing pyrolysis temperature or decreasing particle size of bulk BC, the specific surface area and pore volumes of the derived BC colloids increased, the kinetics model fitted adsorption rates ( k 2 ) of the three organics by the BC colloids all largely decreased, and the Langmuir model fitted adsorption capacities ( Q max ) increased. The highest Q max was obtained by BC colloids from the smallest (250 nm) bulk BC with the highest pyrolysis temperature (700 °C), being 212 μmol g −1 for PHN, 815 μmol g −1 for ATZ, and 72.4 μmol g −1 for OTC. The adsorption was reversible for PHN and ATZ, while significant desorption hysteresis was observed for OTC on BC colloids with middle pyrolysis temperatures (300–500 °C). The underlying mechanisms including hydrophobic interaction, π–π electron donor-acceptor interaction, molecular size effect, and irreversible reactions were discussed to explain the difference in the adsorption and desorption behaviors. The findings increased our understanding of the environmental fate and risk of BC.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2020
·Vol. 10
·期 4
·402
·
IF 3.52
Depeng Han,Wang Yin,Ali Arslan,Tongrui Liu,Yan Zheng,Shuqian Xia
Repolymerization is a huge problem in the storage and processing of biomass pyrolysis liquid (PL). Herein, to solve the problem of repolymerization, mild catalytic hydrotreatment of PL was conducted to convert unstable PL model compounds (hydroxyacetone, furfural, and phenol) into stable alcohols. An Ni/SiO2catalyst was synthesized by the deposition-precipitation method and used in a mild hydrotreatment process. The mild hydrotreatment of the single model compound was studied to determine the reaction pathways, which provided guidance for improving the selectivity of stable intermediate alcohols through the control of reaction conditions. More importantly, the mild hydrotreatment of mixed model compounds was evaluated to simulate the PL more factually. In addition, the effect of the interaction between hydroxyacetone, furfural, and phenol during the catalytic hydrotreatment was also explored. There was a strange phenomenon observed in that phenol was not converted in the initial stage of the hydrotreatment of mixed model compounds. Thermogravimetric analysis (TGA), Ultraviolet-Raman (UV-Raman), and Brunauer−Emmett−Teller (BET) characterization of catalysts used in the hydrotreatment of single and mixed model compounds demonstrated that this phenomenon did not mainly arise from the irreversible deactivation of catalysts caused by carbon deposition, but the competitive adsorption among hydroxyacetone, furfural, and phenol during the mild hydrotreatment of mixed model compounds.Keywords:repolymerization;biomass pyrolysis liquid;mild catalytic hydrotreatment;mixed model compounds;competitive adsorption
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2020
·
IF 2.717
Wentao Hu,Xi'an Fan,Zigui Luo,Fan Luo,Guangqiang Li,Jian Wang
In this work, Fe/ZnO soft magnetic composite (SMC) is prepared successfully by sol-gel method combined with a pyrolysis process. Formation mechanism and effect of annealing on magnetic properties for the Fe/ZnO SMCs are studied in detail. The results show that Fe/zinc acetate hydrogel mixture will be decomposed into the Fe/ZnO composites by heating above 340 °C. And ZnO is well coated on the surfaces of Fe particles. The Fe/ZnO composite compact has lower total core loss and better frequency stability of magnetic permeability compared with pure Fe compact. In addition, annealing treatment shows an enhanced effect on the magnetic properties for the Fe/ZnO composite compact such as reduced coercivity and increased permeability. The annealed Fe/ZnO SMCs can keep stable magnetic permeability (26) from 50 Hz to 10 kHz, high magnetic induction (1.65 T) and a relatively low core loss of 91.11 kW/m 3 measured under a magnetic flux density of 30 mT at 10 kHz. Therefore, the Fe/ZnO soft magnetic composites prepared by the above-mentioned method provide a great potential application in electromagnetic conversion equipment.
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 27
·11861-11869
·
IF 3.288
Shengnan Yue,Xueguang Wang,Shaoting Li,Yao Sheng,Xiujing Zou,Xionggang Lu,Chunlei Zhang
A highly chemoselective and recyclable ruthenium catalyst for the hydrogenation of halogenated nitroarenes has been prepared via the simple in situ calcination of a mixture of melamine, glucose and ruthenium trichloride. Superfine Ru particles (2.3 ± 0.3 nm) were obtained and highly dispersed in the nitrogen-doped carbon matrix. The Ru/CN catalyst smoothly transforms a variety of halogenated nitroarenes to the corresponding haloanilines with high intrinsic activity (e.g. TOF = 1333 h−1 for p-chloronitrobenzene) and selectivity of more than 99.6%. Furthermore, through an analysis of the products in the reaction process, it was concluded that there are two parallel reaction pathways (a direct pathway and an indirect pathway) for the hydrogenation of aromatic nitro compounds over the Ru/CN catalyst, and the direct pathway was proved to be dominant in catalyzing the intermediates.
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Xiaohua Zhang,Weikun Jiang,Hao Ma,Shubin Wu
This study investigated the relationship between the formation of oligomers and monophenols and lignin structure during pyrolysis regarding two technical lignins from alkali lignin (AL) and corn cob hydrolysis residue lignin (CHRL). The results showed that the molecular weight distribution and inter-unit linkages varied substantially between AL and CHRL, resulting in profound differences in the content of monophenols and oligomers and their distributions in pyrolysis oil (PO). Thereinto, CHRL-PO containing higher monomers content (20.48%) and lower oligomers content (14.31%) relative to AL-PO (5.02%, 22.4%). This was attributed to the higher proportion of guaiacyl (G) units existed in AL, which tended to form oligomers and char. Additionally, the formation pathways of main monophenols from two POs were also different. In light of these findings, the thermal cracking behavior of lignin was closely bound up with its structural features. On one hand, the formation pathways of lignin-derived dimers and tetramers in PO originated from the breaking of a large amount of β-O-4, α-O-4 and C β -C γ bonds during pyrolysis process. Meanwhile, the interconversion relationship between oligomers and monophenols was also existed. Polycyclic aromatic hydrocarbon (PAH) derivatives, on the other hand, were formed by the continuous growth of smaller free radicals because of the evolutionary components (such as phenols, syringols) could form oxygen-related free radicals during the secondary reaction process. Overall, this work provided the research basis and theoretical guidance for balancing the production of oligomers and monophenols through the selection of specific lignin feedstock.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Xiangnan Zhang,Ke Shi,Yuning Liu,Yifan Chen,Kai Yu,Yingying Wang,Hong Zhang,Jie Jiang
Nanoplastics are an emerging topic and have attracted increasing attention due to their widespread existence and potential toxicity on living organisms. The challenges of analytical methods for nanoplastics hinder the deeper understanding of toxicological effects and risk assessment of nanoplastics. In this work, a custom-built electromagnetic heating pyrolyzer was coupled to mass spectrometry for the rapid analysis of nanoplastics. Nanoplastics/microplastics were collected on the heat-resisting filter papers, then directly decomposed into gaseous products in the pyrolyzer and analyzed by mass spectrometry . The polystyrene nanoparticles were used to verify the performance of mass-traced quantification, and recoveries of 106–121% and precision of 9% were obtained. As a proof-of-principle experiment, the saline solution packed by polypropylene infusion bottles was aged for simulating indoor sunlight storage, where nanoplastics/microplastics were analyzed. The abundance models of nanoplastics/microplastics in the saline infusion bottle with aging time were assessed from both quality and quantity, for the first time. Results showed that nanoplastics/microplastics in medical infusion products could be generated under indoor sunlight exposure, which needs more attention due to the potential health risks. The proposed electromagnetic heating pyrolysis-mass spectrometry could be a promising method for assessing nanoplastics/microplastics.
✓ 已验证
DOI
PubMed
高影响因子
ACS Omega
·
2021
·
IF 3.512
Yuqing Zhao,Hang Yang,Jianfa Sun,Yi Zhang,Shibin Xia
In this study, the utilization of secondary pyrolysis oil-based drilling cuttings ash (OBDCA-sp) to activate peroxymonosulfate (PMS) for pollutant removal was investigated. The chemical and physical properties of OBDCA-sp were explicitly analyzed via multiple characterization. The activation efficiency of OBDCA-sp for PMS was tested using humic acid (HA) as the target pollutant. 92% of HA and 52% of total organic carbon in solution could be removed using OBDCA-sp-activated PMS under optimal conditions: OBDCA-sp dosage at 4 g/L, PMS concentration at 4 mmol/L, HA concentration at 10 mg/L, and pH value at 7. After four cycles, 84% removal rate of HA could still be achieved using OBDCA-sp to activate PMS. The main catalysis elements for PMS activation in OBDCA were postulated to be Fe(III), Co(III), and Mn(III), based on X-ray photoelectron spectroscopy and X-ray diffraction results. The results of the quenching experiment indicated that SO4•–, •OH, and 1O2 were the main reactive oxygen species (ROS) and that 1O2 was the dominant ROS in the HA removal process. Radical trapping experiments indicated the presence of SO4•–, •OH, and 1O2 in the reaction system. This study presented a novel utilization path of OBDCA in the field of environmental remediation.
✓ 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）