CRYSTENGCOMM
·
2022
·Vol. 24
·期 24
·4399-4407
·
IF 3.756
Delei Liu,Bing Jiao,Haijun Zhang,Shaowei Zhang,Jianghao Liu
By taking advantage of a microwave and molten-salt co-assisted boro/carbothermal reduction method (MSM-BCTR) and cheap raw materials such as HfO2/ZrO2, B4C and amorphous carbon, three types of (HfxZr(1−x))B2 (x = 0.25, 0.50 and 0.75) solid-solution powders with a single-crystalline rod-like morphology, high compositional uniformity, long lengths of 27.8–41.6 μm and high aspect ratios of 10.1–17.2 were successfully synthesized for the first time. And the required temperature conditions of 1100 °C for 20 min were significantly milder than that required by the molten-salt-assisted reduction method even using strong but high-price elemental boron as a reducing agent. These results demonstrated that the specific MSM-BCTR conditions characterized by molten-salt medium and microwave heating were capable of greatly enhancing not only the kinetics but also the thermodynamic favorabilities of the reactions for synthesizing HfB2 and ZrB2 as well as their solid solutions ((HfxZr(1−x))B2). More interestingly, the investigation on the crystalline growth mechanism of (HfxZr1−x)B2 indicated that under the MSM-BCTR conditions, residual amorphous carbon played an important role in enhancing the oriented growth of (HfxZr(1−x))B2, by preferential adsorption onto their {001} crystal planes and therefore greatly promoting corresponding specific surface energies. This study was expected to provide a feasible way of highly-efficiently and cost-effectively synthesizing ultra-high temperature ceramic powders with a highly-crystalline structure and uniform anisotropic morphology, which were favorable for promoting the oxidation resistance and toughness of their sintered products.
✓ 已验证
产品关联
DOI
高影响因子
TRANSACTIONS OF TIANJIN UNIVERSITY
·
2022
·Vol. 28
·期 5
·414-422
·
IF 0
Shao Wu,Wu Wenjun
Ensuring high power conversion efficiency, partially or completely replacing Pt electrodes with inexpensive materials is one of the important development directions of dye-sensitized solar cells (DSSCs). In this work, we have developed a three-component (MWCNTs, carbon black and graphite) carbon (tri-carbon) electrode material for DSSC devices combined with the advantages of high electron transfer kinetics of MWCNTs, plentiful catalytic sites in crystal edges of carbon black and superior electrical conductivity and catalytic activity of graphite. Using a tri-carbon electrode, a Pt electrode, and two N719-sensitized photoanodes, a parallel tandem dye-sensitized solar cells are assembled obtaining a high PCE of 10.26% ( V oc = 0.70 V, J sc = 19.99 mA/cm 2 , FF = 73.33%). It opens up a new avenue for the development of low-cost and high-performance DSSCs.
✓ 已验证
产品关联
DOI
Processes
·
2022
·Vol. 10
·期 6
·1045
·
IF 3.352
Zonghao Yu,Ruipeng Yu,Shengfang Wu,Weijie Yu,Qijun Song
The practice of odorant analysis can often be very challenging because odorants are usually composed of a host of volatile organic compounds (VOCs) at low concentrations. Preconcentration with solid phase microextraction (SPME) is a conventional technique for the enrichment of these volatile compounds before analysis by headspace gas chromatography-mass spectrometry (GC-MS). However, commercially available SPME products usually bear the defects of weak mechanical strength and high cost. In this work, novel SPME fibers were prepared by a one-pot synthesis procedure from divinylbenzene (DVB), porous carbon powder (Carbon) and polydimethylsiloxane (PDMS). Factors that influence the extraction efficiency, such as extraction temperature, extraction time, salting effects, pH, stirring rate, desorption temperature and time, were optimized. VOCs in landfills pose a great threat to human health and the environment. The new SPME fibers were successfully applied in the analysis of VOCs from the leachate of a cyanobacteria landfill. Quantification methods of major odor contributors were established, and a good linearity (r > 0.998) was obtained, with detection limits in the range of 0.30–0.50 ng/L. Compared to commercial SPME fibers, the new material has higher extraction efficacy and higher precision. Hence, it is suitable for the determination of hazardous odorants of various sources.Keywords:solid phase microextraction;one-pot synthesis;gas chromatography-mass spectrometry;hazardous odorants
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 37
·19852-19858
·
IF 14.511
Yunlong Zhang,Yanan Li,Xiaoshan Wang,Xiaoling Teng,Lu Guan,Hao Yang,Zhengqiu He,Yi Wan,Shiwei Guo,Han Hu,Mingbo Wu
The introduction of redox mediators, for example lithium iodide (LiI), into the catholyte of lithium-ion capacitors (LICs) could provide extra capacity through the iodide-involved redox reactions, allowing an alternative strategy to balance the huge capacity gap between the cathode and anode. Nevertheless, the formidable shuttle effect of the soluble mediators results in deteriorated cycling life. Herein, a metal–organic framework (MOF) interlayer is introduced to prohibit shuttling via physical obstruction and mild chemical attraction. After loading the MOF particles on the separator, the micropore of the MOFs could restrict the intragranular diffusion of the redox mediators while their intergranular migration could be prohibited by the mild chemical adsorption exerted by the MOF particles. The electrochemical evaluation reveals that the employment of the MOF-modified separator could boost the coulombic efficiency and cycling life of the activated carbon (AC) cathode with the LiI-included catholyte. Based on this discovery, a LIC was constructed by pairing the AC cathode with the LiI-involved catholyte and nanostructured Li2TiSiO5 anode at the same mass loading where the MOF-modified separator is employed to prohibit the shuttle of iodine species. Because of the synergistic effects, such a LIC could offer a high energy, large power density, and long cycling life.
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE COMMUNICATIONS
·
2022
·
IF 1.934
Yan Zhao,Guangjian Xing,Hexuan Liu,Wenting Zhang,Qingjun Liu,Chang Zhao,Yan Li,Yanyan Wang
Molybdenum disulfide (MoS 2 ) film has been successfully deposited within a three-dimensional (3D) graphene aerogel (GA) by a magnetron sputtering method to facilely construct MoS 2 /GA composite as a high-performance electrode material of supercapacitor . Through cyclic voltammetry , constant current charge/discharge and electrochemical impedance spectroscopy tests of three-electrode supercapacitor, the electrochemical performance of the MoS 2 /GA composite was evaluated, demonstrating specific capacitances of 187.3 and 175.0 F g −1 at 0.5 and 1 A g −1 , respectively. When cycles 1000 times under the condition of 2 A g −1 , the capacitance retention remains 93.5%. The excellent electrochemical properties of MoS 2 /GA were attributed to the effective structural integration of MoS 2 film and graphene sheets achieved with the magnetron sputtering process, which can further develop other GA-based composites as a feasible technique. The as-prepared MoS 2 /GA with outstanding performance in this work has a promising prospect in supercapacitor application.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Min Zheng,Zhong-Ning Xu,Ming-Lai Fu
Coal to ethylene glycol (CTEG) technology has attracted more and more attention in the past decades. However, the by-production of nitric acid (NA) during oxidative esterification reaction not only causes equipment corrosion but also increases the cost of nitrogen replenishment and wastewater treatment , therefore it is meaningful to convert NA to useful feedstock. Herein, non-metallic B doped activated carbon (B-AC) was prepared and used to activate the reduction of NA. The structure and physicochemical properties of B-AC were firstly examined by SEM, ICP-OES, N 2 adsorption and desorption isotherms, FT-IR, Raman, and XPS spectrum. Furthermore, the catalytic performance and stability of B-AC were evaluated in the batch experiments. Results showed that BET surface area and pore volume of B-AC decreased with the increase of B doping amount, and the content of BC 3 component enhanced with the increase of calcination temperature. B-AC-800(10) with the mass ratio of AC to BA of 10 and the calcinated temperature of800 °C performed the best activity with about 85% and 66% conversion under 2% and 5% of NA solution, and each catalytic performance of B-AC is about 10% higher than pure AC. The slight blockage of pore structure due to the residual NA and the fall of B atoms from B-AC together lead to a decline of about 20% in NA conversion after five cycles. These findings indicated the application of B-AC as a promising catalyst to reduce NA wastewater in the CTEG process.
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2022
·
IF 5.546
Yaolin Hu,Haina Qi,Liu Yang,Yuqi Sheng,Yunrui Xie,Qianli Ma,Hong Shao,Wensheng Yu,Dan Li,Xiangting Dong
Flexible multiple-functional conductive anisotropic membrane made of one-dimensional directional nanomaterial has the potential applicative prospects in advanced electronic skin and strain sensor. Nevertheless, it is hard to prepare aligned polymeric composites with poly-functional high conductive anisotropy and excellent interface properties, so it has been a vital topic to fabricate and investigate such kind of composites. In this work, the fluorescent anisotropic-conduction Janus-typed nanoribbon array membrane (named as FAJNAM for short) with [Eu(TTA) 3 bipy/polymethylmethacrylate (PMMA)]//[carbon black (CB)/PMMA] Janus-typed nanoribbon as construction unit is prepared by di-axial parallel electrospinning with a di-axial parallel spinneret. Since CB will seriously affect the fluorescence intensity of the Eu(TTA) 3 bipy complex, through using Janus-typed nanoribbon as construction unit, Eu complex and CB can be confined in their own regions, realizing efficacious separation of fluorescent and electrical substances to significantly reduce the adverse effects between the two functions so as to obtain excellent red fluorescence and electrical conduction. The percolation zone of CB in Janus-typed nanoribbons membrane is determined. By adjusting the content of CB, the transition from insulation to conductivity of the FAJNAM can be realized. The highest anisotropic conduction ratio reaches ca. 10 8 when the CB content is 10 %. For the first time, the crucial of critical diffusion concentration of two-phase spinning solutions in the parallel electrospinning process is advanced and studied in depth. Furthermore, the relationship between the critical diffusion concentration and the conductive aeolotropism degree has been explored. The concept of critical diffusion concentration is also applicable to other di-axial parallel electrospinning to prepare multi-functional materials, which will be of great significance to optimize electrospinning conditions. This research provides new technical support for the preparation of highly flexible, conductive anisotropy composite materials.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Composites Science
·
2022
·Vol. 6
·期 2
·55
·
IF 0
Tao Wen,Baotao Huang,Li Zhou
Activated carbon (AC) has been widely utilized for the adsorption of pollutants from water. However, it is difficult to recycle the AC after adsorption. In this paper, we report a facile one-pot approach to fabricate magnetic poly(vinyl alcohol)/AC composite gel (mPVA/AC CG) by dropwise addition of an aqueous mixture of PVA, AC and iron ions into the ammonia solution. The obtained mPVA/AC CG after freeze-drying shows porous microstructure and favorable magnetic properties. The utilization of mPVA/AC CG for adsorptive removal of methylene blue (MB) and methyl orange (MO) dyes from water was investigated. The mPVA/AC CG not only exhibited good adsorption performance for both MB and MO dyes but also could be readily recycled using a magnet after adsorption. The adsorption process was well described by the pseudo-second-order kinetic model and the Langmuir isotherm model. Considering the simple fabrication process, good adsorption performance and favorable magnetic separation capability, this work provides a viable strategy for combining the features of AC and magnetic gel for fabrication of applicable magnetic adsorbent.Keywords:magnetic gel;activated carbon;adsorption;dye;methylene blue;methyl orange
✓ 已验证
产品关联
DOI
Nanomaterials
·
2022
·Vol. 12
·期 2
·244
·
IF 5.719
Qingkai Tang,Xinhua Zhu
The structural, optical, dielectric, and magnetic properties of double perovskite La2FeReO6+δ(LFRO) powders synthesized by solid-state reaction method under CO reduced atmosphere are reported on in this paper. Reitveld refinements on the XRD data revealed that the LFRO powders crystallized in an orthogonal structure (Pbnmspace group) with column-like morphology. The molar ratios of La, Fe, and Re elements were close to 2:1:1. XPS spectra verified the mixed chemical states of Fe and Re ions, and two oxygen species in the LFRO powders. The LFRO ceramics exhibited a relaxor-like dielectric behavior, and the associated activation energy was 0.05 eV. Possible origins of the dielectric relaxation behavior are discussed based on the hopping of electrons among the hetero-valence ions at B-site, oxygen ion hopping through the vacant oxygen sites, and the jumping of electrons trapped in the shallower level created by oxygen vacancy. The LFRO powders display room temperature ferromagnetism with Curie temperature of 746 K. A Griffiths-like phase was observed in the LFRO powders with a Griffiths temperature of 758 K. The direct optical band gap of the LFRO powders was 2.30 eV, deduced from their absorption spectra, as confirmed by their green photoluminescence spectra with a strong peak around 556 nm.Keywords:double perovskite La2FeReO6+δpowders;solid-state reaction;dielectric properties;magnetic properties;optical properties;structural characterization
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DESALINATION
·
2022
·
IF 11.211
Jun Pan,Min Chen,Xianli Xu,Shi-Peng Sun,Zhaohui Wang,Zhaoliang Cui,Weihong Xing,Naser Tavajohi
Large amounts of lignin, hemicellulose , organic matter and inorganic salts are present in pulping and papermaking wastewater. Therefore, the treatment and discharge of pulping wastewater are important issues. We have designed and developed the world's first zero liquid discharge (ZLD) system for it based on pretreatment-membrane-evaporative crystallization integrated technologies . However, for the treatment of high salt reverse osmosis (RO) brine, there are still challenges that need to be addressed. In this work, the feasibility of using a membrane distillation crystallization (MDC) process to treat high saline RO brine was investigated. Two different coating materials , Hyflon AD 40H and perfluoropolyether (PFPE), were applied to improve the membrane surface hydrophobicity for stable and efficient performance. After modification, the water contact angle was up to 138.4 o and 157.7 o for Hyflon/polyvinylidene fluoride (PVDF) and PFPE/PVDF composite membranes, respectively. Moreover, the PFPE/PVDF membrane showed a higher repellency toward RO brine, which is better for the following MDC treatment. During the MDC progress using composite PFPE/PVDF membranes, the salt crystals precipitated and gradually accumulated. More importantly, the final NaCl purity can be up to 94%. Therefore, it is hopeful to improve of the existing ZLD system by MDC operation.
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Yue-Qin Yang,Ling-Ping Xiao,Wen-Zhe Xiao,Xiao-Ying Li,Qiang Wang,Run-Cang Sun
The development of efficient catalysts is of great significance for the hydrodeoxygenation (HDO) of renewable biomass into value-added biofuel and chemicals to mitigate the environmental and energy menace. Herein, we report a sustainable strategy to fabricate ruthenium nanoparticles (NPs) anchored on defective nitrogen-doped carbon (Ru@NC) via a facile pyrolysis of a mixture of ruthenium trichloride and urea with carbon support. The highly distributed Ru NPs, constituted by N-enriched graphene shells, have been established as an excellent catalyst for the selective HDO of lignin- and furan- derivatives toward biofuel upgrade. Impressively, Ru@NC exhibits enhanced catalytic performance to commercial Ru/C, which could be attributed to the presence of the ensemble effects resulting from defective graphene sheet coverage on the Ru surface. Notably, the prepared catalyst was not affected after five successive reaction cycles, demonstrating superior stability and reproducibility. We envision that this work may pave the way for the development of highly efficient novel metal catalysts for heterogeneous catalytic HDO reactions in sustainable energy conversion.
✓ 已验证
产品关联
DOI
高影响因子
Water
·
2022
·Vol. 14
·期 4
·630
·
IF 3.53
Haibing Zhang,Yasong Zhou,Shaohui Guo,Zhipu Wang,Qing Wang
The efficient mineralization of high-concentration aqueous aniline (HCAA) is an issue needing to be resolved. In this study, a hybrid process of ozonation and electrochemical oxidation (ECO) was proposed for improving the mineralization of HCAA (1000 mg·L−1). The results indicated that chemical oxygen demand (COD) removal by the hybrid process was far greater than that of a single ozonation or ECO process, revealing that the hybrid process might avoid low efficiency in late ozonation and initial ECO. Thus, a subsequent combination effect clearly existed. In this hybrid process, ozonation stage time was selected as 60 min for optimal COD removal. The main products of the ozonation stage were maleic and succinic acids, with declining pH which was beneficial to the following ECO stage. Nitrite and nitrate formed during ozonation, which acted as electrolytes for the ECO stage, in which maleic and succinic acids were fully degraded and pH thus increased. Moreover, the aniline degradation mechanism of the hybrid process was deduced, demonstrating the superiority of this hybrid process. Finally, more than 95% COD removal was achieved, which met the COD limit requirement and achieved pH control simultaneously, according to the discharge standards of water pollutants for dyeing and finishing of the textile industry in China (GB 4287–2012).Keywords:aniline;hybrid process;mineralization;ozonation;ECO
✓ 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）