INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Lingjiao Li,Jing Xu,Sheng Zhao,Min Mao,Xuanhao Li
With the development of research on the photocatalytic water splitting and hydrogen (H 2 ) precipitation, cobalt ferrite and molybdate have begun to appear as catalysts for the study of photocatalytic hydrogen precipitation. In this paper, the p-n heterojunction CoFe 2 O 4 /NiMoO 4 (CFO/NMO) is prepared by hydrothermal method . The constructed p-n type (type Ⅱ) heterojunction CFO/NMO has the highest hydrogen evolution (Eosin Y as a sensitizer), which is 7.39 times and 1.95 times that of elemental CFO and NMO, respectively. After the CFO and NMO form a heterojunction, a built-in electric field is formed inside to effectively separate the photogenerated carriers . At the same time, the dense interface of the heterojunction also promotes the transfer of photogenerated carriers and promotes the reduction of H + protons on this catalyst surface . In short, this work provides more possibilities for the field of photocatalytic hydrogen evolution from molybdate and cobalt ferrite compounds.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 16
·50263
·
IF 2.52
Shengsong Dai,Xuejun Yu,Rui Chen,Hong Zhou,Zhiquan Pan
An epoxy resin (EP) with excellent fire retardancy, good transparency, and satisfactory thermal stability has been obtained by introducing a new N/P/S containing flame retardant (HBD) into EP composites. When the phosphorus content was 0.48 wt%, EP/HBD reached V-0 rating with the limiting oxygen index of 33.5%. The cone calorimeter test (CC) indicated that the incorporation of HBD resulted in 1.5 times increase in ignition time, a 50% decrease in the maximum of heat release rates, 40% reduction of total heat release, and 50.7% decrease in total smoke production compared with EP. Besides, the fire-resistant behavior of EP/8% HBD is much better than the EP materials modified by similar P/N/S flame retardants reported in literature. The fire-retardant mechanism of HBD on EP was also analyzed by Raman, scanning electron microscope, Py-GC/MS, and Fourier transform infrared spectroscopy. The results show that HBD plays an important role in the formation of a dense intumescent carbon layer and gas phase quenching.
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 32
·期 4
·1604-1614
·
IF 2.578
Gang Zhang,Dongdong Song,Su Ma,Yanlin Wang,Xiaotian Xie,Yanmao Dong
Currently, the issue of improving the flame-retardant performance of unsaturated polyester resin (UPR) has drawn a lot of attention. In this study, methyl vinyl di (1-thio-2,6,7-trioxal-1-phosphabicyclo [2.2] octane-4-methoxy) silane (MVDOS) with P-N-Si-based cage unit was synthesized, and it was utilized as a reactive flame-retardant monomer to modify UPR. The UPR/MVDOS composites were prepared by introducing different ratios of MVDOS into UPR via the reaction of crosslink. The efficiency of the resulted composites was investigated by using the limiting oxygen index (LOI), vertical burning test, and cone calorimeter test. The results showed that the composites reached the V-0 rate without dripping, and the LOI value was 29.1% when the content of MVDOS was as low as 18 wt%. Cone calorimeter tests revealed the peak of heat release and CO production of UPR/MVDOS-18 were 238.2 KW/m 2 and 0.0167 g/s, which were respectively lower than the ones of neat UPR. The introduction of MVDOS also increased the stability of UPR composites. Furthermore, the scattering electron microscopy, laser Raman spectroscopy, and X-ray photoelectron spectroscopy studies revealed that the incorporation of MVDOS stimulated the UPR matrix to generate char layer with increased graphitization degree, which provided a good barrier to prevent heat and oxygen from being transferred and then protected the materials inside from further burning. This research provides a new way to obtain flame-retardant UPR composites with high performance.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2021
·Vol. 23
·期 2
·1-12
·
IF 2.253
Yang Yongsheng,Gu Bingli,Liu Zhiduo,Chen Da,Zhao Yun,Guo Qinglei,Wang Gang
Doped carbon-based materials have attracted considerable attentions due to their extraordinary optical, thermal, and electronic properties. Herein, we demonstrate a facile and universal approach, which involves the hydrothermal treatment of citric acid and phosphonitrilic chloride trimer (Cl 6 N 3 P 3 ), for the production of nitrogen and phosphorus co-doped graphene quantum dots (N, P-GQDs). The obtained N, P-GQDs with a mean size of about 3.4 nm exhibit bright yellow fluorescence, good-solubility, and attractive optical stability. Although the quantum yield as high as 34.8% has been proved in our synthesized N, P-GQDs, the fluorescence can be also fleetly and selectively quenched by Fe 3+ ions. Therefore, high-performance Fe 3+ sensors are fabricated with N, P-GQDs, with an ultra-sensitive detection limit of 146 nM. Furthermore, high ionic strength, mild acids, and alkaline are demonstrated to have a small impact on the fluorescence intensity of the N, P-GQDs. Finally, the as-synthesized N, P-GQDs, with bright luminescence and excellent biocompatibility, are applied for bioimaging, e.g., fibroblast cells.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Mengran Lou,Ruiying Wang,Lili Yang,Dianzeng Jia,Zhipeng Sun,Luxiang Wang,Yong Guo,Xingchao Wang,Jie Zhang,Hongli Shi
Direct formic acid fuel cells have great application potential in the energy field, but their commercialization is hindered by the CO poisoning and low performance of Pd-based anode catalysts. In this study, novel composite catalysts composed of Pd, organic-inorganic hybrid imidazole ionic liquid polyoxometalates, and N,P-codoped coal-based carbon fibers with good dispersion and smaller Pd nanoparticles were synthesized successfully. Physical and electrochemical characterizations revealed that the as-prepared Pd-based composite catalysts have excellent CO poisoning resistance and enhanced electrocatalytic activity in formic acid electrooxidation. Notably, the CO oxidation onset potential of a catalyst modified by imidazole ionic liquid polyoxometalate with long alkyl chain was 0.1 V lower than that of the unmodified catalyst. The mass activity of the as-prepared Pd catalyst in formic acid oxidation was 754.1 mA mg −1 Pd . It is expected that organic-inorganic hybrid polyoxometalates can be further applied to fuel cell catalysts.
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale Advances
·
2020
·Vol. 2
·期 8
·3334-3340
·
IF 0
Jieyu Xu,Lin Ge,Yajun Zhou,Guangyu Jiang,Liang Li,Yunheng Li,Yongsheng Li
Heteroatom doping has been proved to be an effective strategy to optimize the activity of hydrogen evolution reaction (HER) catalysts. Herein, we report N, P, S multi-doped Mo2C/C composites exhibiting highly efficient HER performance in acidic solution, which are facilely fabricated via annealing of N, P, S-containing MoOx–polyaniline (MoOx–PANI) hybrid precursors. The optimized N, P, S multi-doped Mo2C/C catalyst with a moderate P dopant level (NPS-Mo2C/C-0.5) exhibits excellent performance with an overpotential of 53 mV to achieve a current density of 20 mA cm−2, a Tafel slope of 72 mV dec−1 and good stability in acidic electrolytes. Based on the study of XPS, EPR and 31P MAS NMR, the excellent electrocatalytic performance could be attributed to the effective electronic configuration modulation of both Mo2C nanorods and the carbon matrix, derived from stronger synergistic N, P, S multi-doping coupling effects. This work provides a promising methodology for the design and fabrication of multi-doped transition metal based electrocatalysts via electronic structure engineering.
✓ 已验证
产品关联
DOI
PubMed
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Zhijun Guo,Guoliang Zhang,Lei Wang,Ping Li,Chunshan Li
To meet the increasing demand for methyl methacrylate, a series of Fe modified Cs–P/γ-Al2O3 catalysts were developed through the impregnation method and tested for the aldol condensation of methyl propionate with formaldehyde in a fixed-bed reactor. Through various characterization studies, the physicochemical properties of the catalysts were systematically studied, especially the relationship between the number of the acid sites and catalytic activity. The number of medium acid sites was increased effectively by the addition of Fe, and the catalytic selectivity was improved consequently. Moreover, the reaction conditions were also optimized, and the life span of the optimized catalyst was evaluated. The Cs–P–0.1Fe/γ-Al2O3 showed excellent reusability during a 260 h lifetime experiment.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Weiju Hao,Hao Huang,Ziliang Chen,Lincai Wang,Xiaohua Ma,Mingxian Huang,Xin Ou,Yanhui Guo
Precisely controlling the morphology of electrocatalyst which is critical to its activity and stability remains a key challenge toward efficient overall water splitting. Herein, a distinct temperature-dependent structure modulation effect of electroless plating technique is reported and consequently several bifunctional electrocatalysts with various structures are developed. The optimized bifunctional electrode with cobalt-phosphorus-boron nanoflowers growing on the carbon cloth demands overpotentials of only 91 mV and 294 mV to achieve a current density of 50 mA cm −2 for the hydrogen evolution reaction and oxygen evolution reaction in 1.0 M potassium hydroxide at 25 °C. Moreover, an overall water-splitting device assembled by this electrode can also work at high temperature of 60 °C with excellent long term durability and achieve a current density of 20 mA cm −2 at a cell voltage of around 1.39 V. This work uncovers some structure design principles of highly active electrocatalyst and provides a versatile strategy for structure modulation of the electrocatalyst for pratctical water electrolysis.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 38
·49157
·
IF 2.52
Zhangyu Ma,Linlong Li,Xincui Shi,Zongliang Wang,Min Guo,Yu Wang,Zixue Jiao,Congxiao Zhang,Peibiao Zhang
Polyetheretherketone (PEEK) is a promising bone and dental tissue engineering material with excellent mechanical properties and biocompatibility, but its biological inertness deficiency limits its clinical applications. In this study, poly(sodium p-styrene sulfonate) (pNaSS) was grafted onto PEEK surface by ultraviolet (UV) induced polymerization to enhance its osteogenic activities. Attenuated total reflectance Fourier transformed Infrared (ATR-FTIR) spectroscopy, scanning electron microscopy (SEM), and contact angle (CA) analysis were carried out to prove the success of grafting polymerization. Toluidine blue O (TBO) colorimetric assay was utilized to quantify the graft amounts of pNaSS. Results showed that the amounts of grafted pNaSS on the PEEK surface could be well-controlled from 0.59 ± 0.07 mmol/cm 2 to 5.08 ± 0.20 mmol/cm 2 , through adjusting the UV irradiation time and monomer concentration. The hydrophilicity of PEEK surface was increased and the in vitro mineralization ability was promoted with the introduction of pNaSS. Besides, this surface modification method did not influence the intrinsic mechanical properties of PEEK. in vitro biological studies revealed that cell adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 cells were enhanced with the increase of graft amounts.
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Yongjun Sun,Shengbao Zhou,Wenquan Sun,Sichen Zhu,Huaili Zheng
In order to effectively remove the dissolved heavy metals and the heavy metals on the colloidal particles during the flocculation process, a novel dual-functional chitosan flocculant CMCTS-g-P(AM-CA) is prepared by ultraviolet light-initiated graft polymerization using CMCTS, AM, and ammonium dithiocarbamate. The main influencing factors of monomer concentration, monomer ratio, pH value, photoinitiator concentration, and illumination time are investigated on the basis of intrinsic viscosity, grafting rate, and grafting efficiency of CMCTS-g-P(AM-CA). Characterization results provided empirical evidence for existence of chelating groups. In addition, CMCTS-g-P(AM-CA) was applied to treat the simulated heavy metals and electroplating wastewater. The effect of CMCTS-g-P(AM-CA) dosage, pH value, and reaction G value on flocculation efficiency was also explored. After the two-stage flocculation, the residual concentration of Ni(II), COD, and turbidity of actual electroplating wastewater decreased to 0.96 mg/L, 93.00 mg/L, and 1.71 NTU after flocculation tests at optimal condition, respectively. Finally, the “3E” triangular evaluation model is established and applied to evaluate the flocculation performance of CMCTS-g-P(AM-CA) on the actual heavy metal wastewater further, thereby proving its excellent chelation flocculation performance.
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Jingjing Li,Zhiyu Wang,Xiaodong Tang,Xiaojie Lei
The olefin alkylation of thiophenic sulfur (OATS) in model fluid catalytic cracking gasoline was carried out using the temperature-responsive catalyst which was prepared by mixing the temperature-responsive ionic liquid (TRIL) and p-toluenesulfonic acid (PTSA) with the mass ratio 1:10 (10% TRIL–PTSA). The liquid–liquid biphasic system was formed during the OATS and returned to the liquid–solid state automatically after completion of the reaction at cooling temperature, which enhanced the mass transfer efficiency and separation ability of oil and the catalyst. As for 10% TRIL–PTSA, the acid strength was adjusted properly by TRIL, and the anionic cluster of [−SO3(−SO3H)x]– was also found by Fourier transform infrared, 1H NMR, and thermogravimetric–differential scanning calorimetry, which displayed a better catalyst performance over PTSA. Moreover, the effects of various factors were fully discussed, including the reaction temperature, reaction time, and catalyst dosage. Under optimal conditions, the conversion of thiophene (T) can reach 100% and it can remain unchanged during 10 recycles. Furthermore, apparent reaction kinetics for OATS was discussed. It suggested that the alkylation of T conformed to the pseudo-first-order kinetic characteristic, and the apparent activation energy was 47.6 kJ/mol. Finally, the synergistic catalysis mechanism was proposed.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 11
·5750-5757
·
IF 11.301
Liang Sun,Zhicheng Shi,Huanlei Wang,Kun Zhang,Davoud Dastan,Kai Sun,Runhua Fan
Polymer dielectric composites are of great interest as film capacitors that are widely used in pulsed power systems. For a long time, huge efforts have been devoted to achieving energy densities as high as possible to satisfy the miniaturization and high integration of electronic devices. However, the discharge efficiency which is particularly crucial to practical applications has gained little attention. With the target of achieving concurrently improved energy density and efficiency, a class of rationally designed bilayer composites consisting of a pure polyetherimide layer and a BaTiO3/P(VDF-HFP) composite layer were prepared. Interestingly, the bilayer composites exhibit ultrahigh discharge efficiencies η (>95%) under external electric fields up to 400 kV mm−1 which are much higher than most of the so far reported results (η < 80%). Meanwhile, a low loss (tan δ < 0.05 @ 10 kHz) comparable to that of the pure polyetherimide is obtained. In addition, the bilayer composites show impressive improvements in breakdown strengths Eb, i.e., 285%, 363%, 366% and 567% for composites with 5 vol%, 10 vol%, 20 vol% and 40 vol% BaTiO3, compared to their single layer counterparts, resulting in obviously improved energy densities Ud. In particular, the bilayer composite with 10 vol% BaTiO3 displays the most prominent comprehensive energy storage performance, i.e., η ∼ 96.8% @ 450 kV mm−1, Ud ∼ 6 J cm−3 @ 450 kV mm−1, tan δ ∼ 0.025 @ 10 kHz, and Eb ∼ 483.18 kV mm−1. The ultrahigh discharge efficiencies and high energy densities, along with low loss and breakdown strengths, make these bilayer composites ideal candidates for high-performance dielectric energy-storage capacitors.
✓ 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）