NEW CARBON MATERIALS
·
2018
·
IF 1.171
Hai-xiao Yang,He-xiang Han,Ji-tong Wang,Wen-ming Qiao,Li-cheng Ling
Novel high-carbon-yield pitches were prepared through the iodination of 1-methylnaphthalene (1-MNP) followed by dehydroiodination/polycondensation. 1-MNP was first iodinated by I 2 with the aid of I 2 O 5 , yielding mainly 1-iodo-4-MNP. Then, a thermal-dehydroiodination reaction at a comparatively low temperature of 130–180 o C was carried out to condense the iodinated products to obtain the pitches. The structures of the iodinated products and pitches were investigated by TG, GC-MS, 1H-NMR and FT-IR. Results indicated that the iodination selectivity ( S mb) reached 96.4% when 0.75 mol I 2 and 0.18 mol I 2 O 5 reacted with 1 mol 1-MNP at 60 o C for 24 h in acetic acid. Ring-hydrogenation products (tetralin, 5-methyltetralin) and methyl migration products (2-MNP, dimethylnaphthalene and trimethylnaphthalene) were found in the pitches by analyzing their methanol-soluble fractions. Dehydroiodination substantially increased the degree of polymerization and carbon yield of the pitches. The pitches exhibited high polymerization degrees (toluene soluble fraction less than 12 wt%), high carbon yields (54–66 wt%) and complicated 1-MNP molecular assembly patterns including α-α′, α-β′, β-β′, depending on dehydroiodination temperature and time. The iodination/dehydroiodination approach is simple, mild and clean for preparation of high quality pitches for high performance carbon materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 21
·3751
·
IF 5.719
Shindume Lomboleni Hamukwaya,Huiying Hao,Melvin Mununuri Mashingaidze,Tingting Zhong,Shu Tang,Jingjing Dong,Jie Xing,Hao Liu
Lead-free, bismuth-based perovskite solar cells (PSCs) are promising, non-toxic, and stable alternatives to lead-based PSCs, which are environmentally harmful and highly unstable under deprived air conditions. However, bismuth-based PSCs still suffer from low-power-conversion efficiency (PCE) due to their large bandgap and poor film morphology. Their poor film-forming ability is the greatest obstacle to Cs₃Bi₂I₉ progress in thin-film solar cell technology. This study synthesizes novel, lead-free perovskites with a small bandgap, excellent stability, and highly improved photovoltaic performance by integrating different amounts of potassium iodide (KI) into a perovskite precursor solution. KI incorporation improves the crystallinity of the perovskite, increases the grain size, and decreases the potential contact distribution, which is demonstrated by X-ray diffraction, electronic scanning microscopy, atomic force microscopy, and ultraviolet-visible spectroscopy. The Cs₃Bi₂I₉ PSC device with 2 vol. % incorporation of KI shows the highest PCE of 2.81% and Voc of 1.01 V as far as all the Bi-based cells fabricated for this study are concerned. The study demonstrates that incorporating KI in the Cs₃Bi₂I₉ perovskite layer highly stabilizes the resultant PSC device against humidity to the extent that it maintains 98% of the initial PCE after 90 days, which is suitable for solar cell applications. The devices also demonstrate greater resistance to airborne contaminants and high temperatures without encapsulation, opening up new possibilities for lead-free Cs₃Bi₂I₉ PSCs in future commercialization.Keywords:Cs3Bi2I9perovskite solar cells;KI incorporation;crystallinity;morphology;cell stability
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Menglin Wu,Shunke Ding,Zhongqi Cao,Zhenqi Du,Yuyang Tang,Xiaoyan Chen,Wenhai Chu
Iodinated disinfection by-products (I-DBPs) have attracted extensive interests because of their higher cytotoxicity and genotoxicity than their chlorinated and brominated analogues. Our recent studies have firstly demonstrated that cooking with seaweed salt could enhance the formation of I-DBPs with several tens of μg/L level. Here, I-DBP formation and mitigation from the reaction of disinfectant with Laminaria japonica (Haidai), an edible seaweed with highest iodine content, upon simulated household cooking process was systematically investigated. The total iodine content in Haidai ranged from 4.6 mg-I/g-Haidai to 10.0 mg-I/g-Haidai, and more than 90% of iodine is soluble iodide. During simulated cooking, the presence of disinfectant simultaneously decreased iodide by 15.0–32.8% to 2.7–5.8 mg/L and increased total organic iodine by 1.3–10.9 times to 0.5–1.8 mg/L in Haidai soup, proving I-DBP formation. The concentrations of iodinated trihalomethanes and haloacetic acids were at the levels of several hundreds of μg/L and several μg/L, respectively, which are 2–3 orders and 1–2 orders of magnitude more than those in drinking water . Effects of key factors including disinfectant specie, disinfectant dose, temperature and time on I-DBP formation were also ascertained, and temperature and disinfectant specie played a decisive role in the formation and speciation of I-DBPs. In order to avoid the potential health risk from the exposure of I-DBPs in Haidai soup, it is prerequisite to soak and wash dry Haidai sample over 30.0 min before cooking, which could effectively remove major soluble iodide. In general, this study provided the new insight into I-DBP formation from daily household cooking with Haidai and the corresponding enlightenment for inhabitants to eat Haidai in daily life.
研究领域:
环境科学
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食品安全
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED PHYSICS LETTERS
·
2015
·Vol. 107
·期 6
·
IF 3.302
Liu Lijia,McLeod John A.,Wang Rongbin,Shen Pengfei,Duhm Steffen
The formation mechanism of perovskite methylammonium lead triiodide (CH 3 NH 3 PbI 3 ) was studied with in situ X-ray photoelectron spectroscopy (XPS) on successive depositions of thermally evaporated methylammonium iodide (CH 3 NH 3 I) on a lead iodide (PbI 2 ) film. This deposition method mimics the “two-step” synthesis method commonly used in device fabrication. We find that several competing processes occur during the formation of perovskite CH 3 NH 3 PbI 3 . Our most important finding is that during vapour deposition of CH 3 NH 3 I onto PbI 2 , at least two carbon species are present in the resulting material, while only one nitrogen species is present. This suggests that CH 3 NH 3 I can dissociate during the transition to a perovskite phase, and some of the resulting molecules can be incorporated into the perovskite. The effect of partial CH 3 NH 3 substitution with CH 3 was evaluated, and electronic structure calculations show that CH 3 defects would impact the photovoltaic performance in perovskite solar cells. The possibility that not all A sites in the A PbI 3 perovskite are occupied by CH 3 NH 3 is therefore an important consideration when evaluating the performance of organometallic trihalide solar cells synthesized using typical approaches.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2023
·
IF 9.9
Jiancong Zhang,Yang Zi,Wei Shan,Prayoon Songsiriritthigul,Min Luo,Than Zaw Oo,Mono Zaw,Nyein Wint Lwin,Su Htike Aung,Guangguo Ying,Fuming Chen
Nowadays, stable photoelectrochemical seawater desalination is a challenge. In this work, an environmentally friendly WO 3 /BiVO 4 photoanode is reported to achieve stable solar-driven redox desalination . The WO 3 /BiVO 4 photoanode was prepared by the hydrothermal method and drop-casting and the cathode is the activated carbon coated on graphite paper. Within the desalination system , the I − /I 3 − redox species are recycled between anode/cathode chambers. In the short-circuit state, with illumination as the driving force, the salt removal rate of 65.03 μg/(cm 2 ·min) is obtained without the electric consumption. During the desalination process, the energy output process can be implemented with a salt removal rate of 29.8 μg/(cm 2 ·min) with constant current discharge. Importantly, the solar desalination system based on WO 3 /BiVO 4 photoanode is quite stable. Within the five cycles, the variation of the salt removal rate is within 3.32 μg/(cm 2 ·min). As the practical application, the seawater is desalted to the freshwater standard using the current system, in which the conductivity decreases to 0.96 mS/cm from 53 mS/cm. This work provides a feasible approach to developing stable and efficient solar-driven seawater desalination for long-term usage.
研究领域:
环境科学
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材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2014
·
IF 1.552
Chunyu Zhao,Yantao Shi,Zhiyong Zhong,Tingli Ma
Counter electrodes (CEs) for dye-sensitized solar cells (DSCs) are important for collecting electrons and catalyzing the iodide/tri-iodide reaction. Pt CEs are commonly prepared by magnetron sputtering , which is expensive and requires vacuum conditions. Incorporating the low cost surfactant Span-85 improved the adhesion between the Pt particles and conductive substrate, and allowed Pt-based CEs to be screen-printed. The screen-printed CE was compared with those prepared by dip-coating and spin-coating. Photoelectric conversion efficiencies of 7.30%, 6.96% and 7.03% were achieved for DSCs containing screen-printed, dip-coated and spin-coated CEs, respectively. Optical transmittance measurements, scanning electron microscopy, and film adhesion tests results showed that the surfactant improved film adhesion and increased transmittance, and the screen-printed CEs exhibited comparable transmittance to the dip-coated CEs. Screen-printing resulted in Pt particles being more uniformly distributed on the substrate, when compared with dip-coating or spin-coating. Cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel-polarization curves showed that the catalytic activity of the screen-printed Pt-based CEs were higher than that of the other CEs. Screen-printing is suitable for realizing the low-cost large-scale production of large Pt-based CEs.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
Biosensors-Basel
·
2023
·Vol. 13
·期 6
·585
·
IF 5.4
Yunping Lai,Beirong Yu,Tianran Lin,Li Hou
A multicolor visual method for the detection of hydrogen peroxide (H2O2) was reported based on the iodide-mediated surface etching of gold nanostar (AuNS). First, AuNS was prepared by a seed-mediated method in a HEPES buffer. AuNS shows two different LSPR absorbance bands at 736 nm and 550 nm, respectively. Multicolor was generated by iodide-mediated surface etching of AuNS in the presence of H2O2. Under the optimized conditions, the absorption peak Δλ had a good linear relationship with the concentration of H2O2with a linear range from 0.67~66.67 μmol L−1, and the detection limit is 0.44 μmol L−1. It can be used to detect residual H2O2in tap water samples. This method offered a promising visual method for point-of-care testing of H2O2-related biomarkers.Keywords:iodide;gold nanostar;H2O2
研究领域:
分析化学
·
生物医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 74
·70460-70467
·
IF 3.289
Ye Zhang,Zhe Sun,Chengzhen Shi,Feng Yan
An imidazolium thiopropionate-based redox couple is introduced as an improved organic alternative to iodide/triiodide (I−/I3−) couples for dye-sensitized solar cells (DSSCs). The synthesized thiolate/disulfide (BMIT/BMIDT) redox couple shows negligible absorption in the visible spectral range, and higher redox potential (+0.72 V vs. NHE) compared with that of I−/I3−. With the optimized redox couple (such as 0.1 M/0.1 M)/dye N719 formulation, the fabricated DSSCs exhibit an average overall power conversion efficiency (PCE) of 6.8% and 8.1% under the simulated air mass 1.5 solar spectrum illumination at 100 and 50 mW cm−2, respectively. However, a higher concentration of the BMIT/BMIDT redox couple (such as 0.4 M/0.4 M) decreases the PCE of the devices, due to the desorption of dye molecules from the TiO2 photoelectrode surface.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2012
·Vol. 4
·期 10
·3471-3477
·
IF 1.547
Xu Han,Lianghui Cao,Heyong Cheng,Jinhua Liu,Zigang Xu
Ion-pair reversed phase high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (RP-HPLC-ICP-MS) has been used to determine two inorganic iodine species (I− and IO3−) and two organic iodinated amino acids (MIT and DIT) in seaweed and seawater samples within 5 min. The mobile phase used for a reversed phase C18 column was as follows: 2.0 mM tetraethylammonium hydroxide, 10 mM L-phenylalanine and 1% methanol (pH 8.9). Values of 1.5 mL min−1 for the flow rate of the mobile phase and 25 °C for the column temperature were selected for rapid separation of iodine species. The detection limits for IO3−, I−, MIT and DIT were 0.061, 0.052, 0.079 and 0.24 μg L−1, each, and the repeatabilities of peak height and peak area (20 μg L−1 for iodide and iodate, 40 μg L−1 for MIT, 100 μg L−1 for DIT) were all lower than 4%. Under the optimized conditions, the proposed method was successfully applied for the speciation analysis of iodine in seaweed and seawater samples. Recoveries of IO3−, I−, MIT and DIT in seaweed and seawater samples were between 90 and 110%. All results prove its advantages including high sensitivity, environmentally friendly, low time consumption, which are beneficial for routine analysis of iodine speciation in environmental and food fields.
研究领域:
分析化学
·
环境科学
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2022
·
IF 4.654
Shuofan Li,Ying Liu,Yahe Zhang,Jianxun Wu,Weilai Zhang,Quan Shi
Olefins are ubiquitous in processed petroleum streams undergoing thermal and catalytic cracking processes. However, the molecular characterization of olefins is often troublesome as a result of the presence of cycloalkanes or aromatic hydrocarbons, which cannot be distinguished from each other because of their identical molecular composition. This study provides a novel method to selectively characterize the molecular composition of olefins in processed petroleum streams. The olefins were selectively converted into halohydrocarbons with iodine monochloride as a reaction reagent and then subjected to high-resolution mass spectrometry analysis with positive-ion atmospheric pressure chemical ionization. The molecular composition of olefins in the coker diesel, the coker gas oil, and the pyrolysis gas oil was successfully characterized by the method, which indicates that the linear mono-olefins are often the dominant species. The derivatization also enables the identification of co-eluted individual compounds in gas chromatographic analysis. The method could be applicable to other streams from complex fossil fuels.
研究领域:
化学
·
能源科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2014
·
IF 5.211
Guiqiang Wang,Juan Zhang,Shuai Kuang,Shaomin Liu,Shuping Zhuo
Cobalt sulfide (CoS)/graphene composites are prepared by a facile one-pot hydrothermal method in the presence of graphene oxide and used as a low-cost substitute for Pt to fabricate the counter electrode in dye-sensitized solar cells. TEM , SEM and AFM characterizations show that CoS nanoparticles are highly dispersed on the surface of graphene nanosheets . This unique nanostructure affords a promising synergistic effect on electrocatalytic performance for the iodide/triiodide redox reaction . Electrochemical impedance spectroscopy and Tafel polarization analyses confirm that the CoS/graphene composite indeed provides simultaneously superior electrocatalytic activity and enhanced electrical conductivity as the counter electrode for dye-sensitized solar cells. Under an illumination of AM 1.5 simulated solar light (100 mW cm −2 ), the dye-sensitized solar cell based on the CoS/graphene composite counter electrode achieves a conversion efficiency of 7.08%, which is comparable to that of the cell based on Pt electrode and much higher than those of the devices with CoS and graphene electrodes.
研究领域:
材料科学
·
能源技术
·
纳米技术
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2014
·
IF 4.794
Jun He,Jingjing Duan,Huatian Shi,Jian Huang,Jiahong Huang,Lin Yu,Matthias Zeller,Allen D. Hunter,Zhengtao Xu
The major discovery here is a robust and water-stable metal–organic framework (MOF) material capable of reversible binding of the volatile and reactive molecules of ICl and I2. The immobilization of I2 and ICl, as well as their controllable release thus achieved, is to facilitate the wide-ranging applications of these volatile species as catalysts and reagents in chemical and industrial processes. The framework material TMBP·CuI (hereafter TCuI) can be conveniently prepared in quantitative yields by heating CuI and the organic linker TMBP (3,3′,5,5′-tetramethyl-4,4′-bipyrazol) in acetonitrile. The microporous three-dimensional net of TCuI features CuI chains that contribute to efficient and reversible binding of ICl and I2 molecules, to result in the stoichiometrically well-defined adducts of TCuI·ICl and TCuI·I2, respectively. Moreover, the confinement of a volatile compound like ICl within the MOF medium provides unique opportunities to enhance its reactivity and selectivity as a chemical reagent, as is exemplified by the iodination reactions examined herein. With this exemplary study, we intend to stimulate interest in further exploring MOFs and other porous media (e.g., porous polymers) for entrapping ICl and other volatile reagents (e.g., Br2, SCl2, S2Cl2, and SOCl2) and for potentially novel reactivity associated with the porous medium.
研究领域:
材料科学
·
化学工程
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）