ENERGY
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2020
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IF 6.082
Yan Wang,Dong-Liang Zhong,Peter Englezos,Jin Yan,Bin-Bin Ge
The kinetics of semiclathrate hydrates formation with CO 2 in the presence of tetra- n -butyl ammonium bromide (TBAB), tetra- n -butyl phosphonium bromide (TBPB), and TBAB + TBPB were investigated. The experiments were conducted at the stoichiometric concentration of TBAB hydrate (2.57 mol%) and three subcoolings (Δ T = 6 K, 9 K, and 12 K) with the initial pressure fixed at 2.8 MPa. It was found that adding TBPB into the TBAB solution can promote hydrate nucleation, and this promotion effect at a lower subcooling (Δ T = 6 K) was stronger compared to that at higher subcoolings (Δ T = 9 K and 12 K). The gas consumption obtained in TBAB, TBPB, and TBAB + TBPB solutions decreased with the increase of subcooling, despite the increase of the rate of hydrate growth. At a given subcooling, gas consumption (CO 2 uptake) in TBAB + TBPB solutions was greater than that in TBAB and TBPB solutions, indicating that hydrate formation kinetics and the CO 2 storage capacity were improved in the TBAB + TBPB solution. The largest gas consumption was obtained at Δ T = 6 K in the TBAB + TBPB solution, which was 28.7% and 17.2% larger than those obtained in TBAB and TBPB solutions, respectively. Therefore, a mixture of TBAB + TBPB is a promising option to improve the kinetics of semiclathrate hydrate formation with CO 2 .
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2022
·
IF 4.177
Hang Mei,Zi-Yan Wang,Yue Zhai,Qiang-Qiang Zhu,Le Wang,Pei Liang
Vacancy-ordered double perovskites, the variant of metal-halide perovskites, have excellent potential for use in optoelectronic and thermoelectric devices. A narrow region of forming the stable vacancy-ordered double perovskite Cs2PdBr6 by the chemical potential calculation via the first principles method was reported. Perdew–Burke–Ernzerhof functionals were used to investigate the possible intrinsic defects and the corresponding formation energy of Cs2PdBr6. Under the Pd-rich condition, the VBr defect was spontaneously formed as it has the lowest formation energy among all donor defects. In contrast, the sample became a p-type conducting material with a high hole concentration under the Pd-poor condition. This indicates that the defect-induced decline of photoelectric properties of Cs2PdBr6 can be alleviated by regulating the VBr defect alone. Finally, the Cs2PdBr6 microcrystals were fabricated via hydrothermal synthesis. In addition, XRD, PL, and Raman spectroscopy were also performed on Cs2PdBr6 powder to characterize the microstructure and optical properties of the compound; the results showed that VBr defects can be formed spontaneously, which is consistent with our theoretical calculations.
研究领域:
材料科学
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物理化学
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2023
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IF 12.8
Yifei Zhang,Zhechao Hua,Xuewen Zhang,Kaiheng Guo,Jingyun Fang
Solar photolysis of free chlorine (solar/chlorine) in bromide-containing water occurs under various scenarios, such as chlorinated reservoirs and outdoor swimming pools, and the formation of chlorate and bromate is an important issue in the system. We reported unexpected trends for the formation of chlorate and bromate in the solar/chlorine system. Excess chlorine inhibited the formation of bromate, i.e., increasing chlorine dosages from 50 to 100 μM reduced the bromate yield from 6.4 to 1.2 μM in solar/chlorine at 50 μM bromide and pH 7. The yield of bromate in solar/chlorine at 100 μM chlorine and 50 μM bromide in 240 min was 18.8% of that at 50 μM bromine only. The underlying mechanism was that HOCl can react with bromite (BrO 2 − ) to form HOClOBrO − , whose multi-step transformation finally formed chlorate as the major product and bromate as the minor product. This reaction overwhelmed the oxidation of bromite to form bromate by reactive species, such as • OH, BrO • and ozone. On the other hand, the presence of bromide greatly enhanced the formation of chlorate. Increasing bromide concentrations from 0 to 50 μM enhanced the chlorate yields from 2.2 to 7.0 μM at 100 μM chlorine. The absorbance of bromine was higher than that of chlorine, thus the photolysis of bromine formed higher levels of bromite at higher bromide concentrations. Then, bromite rapidly reacted with HOCl to form HOClOBrO − and it further transformed to chlorate. Additionally, 1 mg L − 1 NOM had a negligible effect on bromate yields in solar/chlorine at 50 μM bromide, 100 μM chlorine and pH 7. This study demonstrated a new pathway of chlorate and bromate formation in the solar/chlorine system with bromide.
研究领域:
环境科学
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化学
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产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 23
·8259
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IF 4.927
Ping Gao,Suwen Cheng,Jiaxin Liu,Junjie Li,Yanyan Guo,Zhengtao Deng,Tianshi Qin,Aifei Wang
Lead-free all-inorganic halide materials with different Mn2+-based crystal structures (Cs3MnBr5and CsMnBr3) were obtained using a convenient synthetic method. Cs3MnBr5had a bright green emission (522 nm), with a unique single-exponential lifetime (τavg= 236 µs) and a high photoluminescence quantum yield (82 ± 5%). A red emission was observed in the case of the CsMnBr3structure with a two-exponential fluorescence decay curve, and the lifetime was 1.418 µs (93%) and 18.328 µs (7%), respectively. By a judicious tuning of the synthetic conditions, a mixed phase of Cs3MnBr5/CsMnBr3was also produced that emitted white light, covering almost the entire visible spectrum. White-light-emitting diodes (WLEDs) with color coordinates (0.4269, 0.4955), a color temperature of (3773 K), and a color rendering index (68) were then fabricated using the as-prepared powder of mixed phases of Cs3MnBr5/CsMnBr3with a commercial UV LED chip (365 nm).Keywords:perovskite;Cs3MnBr5;manganese halide;phosphor;white LEDs
研究领域:
材料科学
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光学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
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2014
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IF 3.679
Tie Jun Lin,Xuan Meng,Li Shi
A non-petroleum route to produce acrylic acid was investigated through hydrocarboxylation of acetylene with CO and water in the presence of Ni 2 O 3 and cupric bromide as combined catalysts. The activity of Ni 2 O 3 was compared with various homogeneous catalysts; the effect of initial total pressure, reaction temperature, molar ratio of CO/C 2 H 2 , the volume ratio of solvent/water, the catalyst amount and the role of promoters have been studied in detail. It was found that the acrylic acid space-time-yield as high as 764.6 mol AA/(mol Ni h) was obtained under the optimal experimental conditions. The Ni 2 O 3 catalyst could be reused at least five times without obvious loss of activity. The characterization of recovered catalysts by XRD, XPS, SEM and TG–DTG revealed that the state of nickel remains unchanged during the reaction, and there are three types of soft coke deposited on the surface of the catalyst. The catalysts can be regenerated through calcination within 400 °C according to TG curve.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
BIOMASS & BIOENERGY
·
2024
·
IF 5.8
Yufa Gao,Wenlu Zhang,Mohammad Ali Asadollahi,Chao Liu,Guang Yu,Haiming Li,Bin Li
Clean and efficient pretreatment is a critical process for producing cellulosic sugar platform for the production of advanced biofuels and chemicals. Combining a chemical treatment with ball milling is a relatively simple and environmentally friendly procedure, which may reduce the pretreatment time and energy consumption. Hence, in this study, the mineral salts (e.g. ZnCl 2 , ZnBr 2 , LiCl, and LiBr) were used to enhance the ball milling. Firstly, microcrystalline cellulose (MCC) as a model compound of pure cellulose was pretreated by mineral salt-assisted ball milling to investigate the effect of mineral salt and ball milling for promoting cellulose saccharification. LiBr showed the best effect to improve the effectiveness of ball milling pretreatment, and the glucose yield of saccharification reached up to 93.8 % under the optimal conditions. Then, corncob residue (CCR) as a distinctive starting material was pretreated by LiBr-assisted ball milling, and the corresponding glucose yield of saccharification (48 h) with enzyme dosage of 5 FPU/g-CCR was as high as 97.4 %. Characterization verified that, the effect of LiBr and ball milling could more effectively break hydrogen bonds and crystalline structure of cellulose, thus highly promoting the followed enzymatic saccharification without lignin removal and washing after LiBr-assisted ball milling pretreatment. This work can help to understand the effect of combining mineral salt with ball milling, which is beneficial to the development of clean and effective pretreatment approach for lignocellulose biorefinery.
研究领域:
生物能源
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生物质转化
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Gan Wan,Tao Chen,Linlin Xu,Lushi Sun
Waste printed circuit boards (WPCBs) containing brominated flame retardants (BFRs) would result in serious environmental pollution without pertinent treatments. However, bromine-containing materials have been proven highly efficient for elemental mercury removal (Hg 0 ). This work proposes a win–win strategy of a cost-effective Hg 0 removal method and a highly efficient utilization of WPCB-derived chars. Diverse copper-containing brominated pyrolytic chars of WPCBs were prepared in a fixed bed reactor at 500–700 °C tailored for Hg 0 removal from coal-fired flue gas. The resulting copper-containing pyrolytic chars were proven to have a high Hg 0 removal efficiency. Various characterizations and adsorption curves insights into the impacts of copper, sorbent weights, pyrolysis and adsorption temperatures, on Hg 0 removal efficiency of WPCB-derived chars. The results indicate that copper in WPCBs enhances the fixation of the bromine elements in pyrolytic chars, resulting in improved Hg 0 removal performance. The optimal pyrolysis and adsorption temperatures for pyrolytic chars are 600 °C and 140 °C, respectively. Under optimized conditions, a Hg 0 removal efficiency exceeding 90 % is realized after 30 min of adsorption. Notably, the results indicating the Hg 0 adsorption capacity of WPCB-derived chars rivals that of commercial activated carbons and significantly surpasses that of biochar. Both adsorption kinetics and characterizations affirm that chemisorption is the predominant adsorption method. The C-Br bond and CuO emerge as crucial active sites facilitating the oxidation of Hg 0 .
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
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2020
·
IF 4.019
Ji Lei,Lo-Yueh Chang,Zhaohui Dong,Lijia Liu
Caesium lead bromide perovskite nanocrystals (PNCs) are synthesized using a room-temperature sonochemical method. By mixing equimolar of CsBr and PbBr 2 in Dimethylformamide (DMF), PNCs of CsPbBr 3 structure are formed. Under an identical reaction condition, when EuBr 2 is introduced with the CsBr/PbBr 2 precursor, the resulted product (Eu-PNCs) becomes zero-dimensional Cs 4 PbBr 6 nanocrystals. In addition to the typical green emission observed in both CsPbBr 3 and Cs 4 PbBr 6 , Eu-PNCs has a blue emission band. The overall photoluminescence quantum yield is much higher than the pristine PNCs. We perform detailed analysis of the crystal structure and luminescence properties of the nanocrystals with and without EuBr 2 modification. An X-ray absorption fine structure analysis reveals the local structure of Eu in the PNCs. We propose that the cation-solvent interaction strongly influences the crystallization process of ternary Cs x Pb y Br z , and the formation of Eu-solvent complexes further modifies the PNCs surface resulting in unique luminescence properties.
研究领域:
材料科学
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光学
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DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
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2022
·
IF 4.778
Yang-Peng Lin,Xiao-Ying Huang,Ke-Zhao Du
Bromine is essential to scientific study and industrial application. However, the high toxicity, volatility and corrosivity of Br 2 increase the risk of leakage or explosion. Using solid materials to capture bromine gas can alleviate the leakage and explosion. Herein, X Br 3 ( X = Cs, C 8 H 20 N and C 16 H 36 N) polybromide compounds, were synthesized by the one-pot Br 2 -free solvothermal method. CsBr 3 can reversibly decompose and generate along with the release and capture of Br 2 gas, while Br 2 can be separated from aqueous solution in the form of Et 4 NBr 3 (Et = Ethyl) or Bu 4 NBr 3 (Bu = Butyl). CsBr 3 can release 42.89% Br 2 per molecular formula, which is the highest in reported crystalline materials so far. Bu 4 NBr can enrich Br 2 in water with approximately 73% yield through the hydrophilic-hydrophobic effect. Our study presents an alternative method for solidification and efficient recycle of Br 2 .
研究领域:
化学
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材料科学
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Chengxue Ma,Haijun Cheng,Ruixing Huang,Yijie Zou,Qiang He,Xiaoliu Huangfu,Jun Ma
The oxidation of thallium [Tl(I)] to Tl(III) by chlorine (HOCl) is an important process changing its removal performance in water treatment. However, the role of bromide (Br–), a common constituent in natural water, in the oxidation behavior of Tl(I) during chlorination remains unknown. Our results demonstrated that Br– was cycled and acted as a catalyst to enhance the kinetics of Tl(I) oxidation by HOCl over the pH range of 5.0–9.5. Different Tl(I) species (i.e., Tl+ and TlOH(aq)) and reactive bromine species (i.e., HOBr/BrO–, BrCl, Br2O, and BrOCl) were kinetically relevant to the enhanced oxidation of Tl(I). The oxidation by free bromine species became the dominant pathway even at a low Br– level of 50 μg/L for a chlorine dose of 2 mg of Cl2/L. It was found that the reactions of Tl+/BrCl, Tl+/BrOCl, and TlOH(aq)/HOBr dominated the kinetics of Tl(I) oxidation at pH < 6.0, pH 6.0–8.0, and pH > 8.0, respectively. The species-specific rate constants for Tl+ reacting with individual bromine species were determined and decreased in the order: BrCl > Br2 > BrOCl > Br2O > HOBr. Overall, the presented results refine our knowledge regarding the species-specific reactivity of TI(I) with bromine species and will be useful for further prediction of thallium mobility in chlorinated waters containing bromide.
研究领域:
环境科学
·
水处理化学
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DOI
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Ze-Chen Gao,Yi-Li Lin,Bin Xu,Ying Xia,Chen-Yan Hu,Tian-Yang Zhang,Hao Qian,Tong-Cheng Cao,Nai-Yun Gao
The effect of bromide and iodide on the transformation of humic acid (HA) and algal organic matter (AOM), and the formation of disinfection by-products (DBPs) during UV/chlorination were investigated. Experimental results indicated that the halides effectively inhibited mineralization, with multiple changes in organic molecule transformation due to differences in formation and speciation of reactive halogen species and free halogen. As a consequence, bromide and iodide also played important roles in DBP formation. The DBP yields in HA-containing water during UV/chlorination decreased in the order of iodide loaded > freshwater ≫ bromide loaded, whereas DBP formation in AOM-containing water decreased remarkably with halides added (freshwater > bromide loaded ≫ iodide loaded) at high UV fluence . Moreover, Pearson correlation analysis exhibited weaker correlation between DBPs and water parameters in AOM-containing water, while DBPs in HA-containing water exhibited better correlation with water parameters. For both simulated waters, the theoretical toxicity was calculated and peaked in bromide-containing water, whereas the calculated toxicity in iodide-containing water was comparable or slightly higher than that in freshwater. Therefore, UV/chlorine treatment may achieve good quality water with reduced DBP-associated toxicity in freshwater or iodide-containing water (iodide only), but careful consideration is needed when purifying source waters containing bromide (bromide only), especially for AOM/bromide-containing water.
研究领域:
环境科学
·
水处理工程
✓ 已验证
DOI
高影响因子
STAR Protocols
·
2024
·
IF 1.3
Zengguang Sui,Yunren Sui,Zhixiong Ding,Haosheng Lin,Fuxiang Li,Wei Wu
Summary Passive thermal management with zero-energy consumption and high compactness has drawn increasing attention. Here, we present a protocol to develop a hygroscopic salt-loaded heat sink with a moisture-permeable membrane encapsulation technique for electronics cooling. We describe steps for preparing lithium bromide solution and heat sink with anti-corrosion graphene coating. We then detail procedures for preparing the hygroscopic salt-loaded membrane-encapsulated heat sinks (HSMHSs). The produced low-cost HSMHS exhibits remarkably high thermal management performance without the risks of leakage and corrosion. For complete details on the use and execution of this protocol, please refer to Sui et al. 1
研究领域:
材料科学
·
热能工程
✓ 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）