Journal of the American Chemical Society
·
2014
·
IF 11.444
Xibin Pang,Wei Chang,Chuncheng Chen,Hongwei Ji,Wanhong Ma,Jincai Zhao
The molecules O2 and H2O dominate the cleavage of aromatic sp2 C–C bonds, a crucial step in the degradation of aromatic pollutants in aqueous TiO2 photocatalysis, but their precise roles in this process have remained elusive. This can be attributed to the complex oxidative species involved and to a lack of available models for reactions with a high yield of direct products. Here, we used oxygen-18 isotope labeled O2 and H2O to observe the aromatic ring-opening reaction of the model compound 3,5-di-tert-butylcatechol (DTBC), which was mediated by TiO2 photocatalysis in an aqueous acetonitrile solution. By analyzing the primary intermediate products (∼75% yield), especially the seven-membered ring anhydrides that were formed, we obtained direct evidence for the oxygen atom of dioxygen insertion into a C–C bond of the aromatic ring. This indicates that molecular oxygen is the ultimate ring-opening agent in TiO2 photocatalysis and that it undergoes single O atom incorporation rather than the previously proposed molecular oxygen 1,2-addition processes. The ratio of intradiol to extradiol products depends on the particle size of TiO2 catalysts used, which suggests that the O2 activation is correlated with the available coordination sites on the TiO2 surface in the photocatalytic cleavage of the aromatic ring.
研究领域:
环境科学
·
化学
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2021
·
IF 2.694
Yun-Yun Gao,Xiao-Feng Guo,Lan-Rong Zhao,Shi-Hua Sang
The stable phase equilibria of the ternary system MgBr2 + SrBr2 + H2O at 288 and 308 K were studied with the isothermal dissolution equilibrium method. The compositions of solutions and solid phases have been determined and the equilibrium solid phases at the invariant points were identified with the aid of the X-ray diffraction method. The phase diagrams of this system at 288 and 308 K were both constructed in terms of experimental results. Two stable phase diagrams show that this system is hydrate type I at two temperatures without formation of a solid solution or complex salt. Both the phase diagrams are composed of one invariant point, two univariate curves, and two crystallization regions (SrBr2·6H2O and MgBr2·6H2O). The equilibrium solid phases of the invariant point at 288 and 308 K are both SrBr2·6H2O and MgBr2·6H2O, respectively. Combining the Pitzer single-salt parameters of MgBr2 and SrBr2 reported in the literatures, the unreported mixing ion-interaction parameters θMg,Sr and ΨMg,Sr,Br at 288 and 308 K were fitted with the measured values in this study using the Pitzer equations. The agreement between the experimental values and calculated results in the ternary system MgBr2 + SrBr2 + H2O at 288 and 308 K shows that the parameters fitted with solubilities are reliable.
研究领域:
化学
·
物理化学
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高影响因子
Nature Communications
·
2026
·
IF 18.1
Guo Xuewen,Hu Yongji,Wu Xiaoyi,Shen Yuesong
H 2 O and SO 2 poisoning of cerium-manganese oxide catalysts remains a critical challenge for low-temperature selective catalytic reduction of nitrogen oxides by NH 3 . Here we show that Ti doping of CeO 2 induces lattice contraction and structural distortion, promoting the generation of oxygen vacancies, active oxygen species, and stable Ce-O-Ti interfaces. These strain-engineered structural modifications enhances surface Lewis acidity and triggers a downshift of the d-band center, collectively improving low-temperature catalytic activity and resistance to H 2 O/SO 2 poisoning. The optimized Ce 8 MnTi 2.5 O x catalyst achieves over 90% nitrogen oxides removal across a 150–335 °C temperature range. Under 5 vol.% water and 100 ppm SO 2 , it maintains over 98% efficiency for 12 h at 210 °C. Furthermore, during stepwise heating from 150 °C to 240 °C with 5 vol.% H 2 O and 200 ppm SO 2 , initial activity suppression below 180 °C is fully reversed at or above 210 °C, demonstrating temperature-driven regeneration. This study introduces a strain-engineering strategy for designing robust catalysts for low-temperature nitrogen oxides removal.
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高影响因子
INORGANIC CHEMISTRY
·
2026
·Vol. 65
·期 30
·17706-17716
·
IF 4.6
Jin Cheng-An,Huang Zhiling,Zhang Lianyang,Meng Yue,Xia Guanghua,Xia Shengjie
Photocatalytic nitrogen reduction to ammonia intrinsically
relies
on the synergistic activation of both N 2 and H 2 O molecules by the catalyst. However, achieving simultaneous and
efficient activation of these two species on a single catalyst surface
remains a formidable challenge, constrained by poor N 2 adsorption
and the high dissociation energy barrier of the N≡N triple
bond. To address this, a vacancy engineering strategy was adopted
to design and fabricate a Bi 2 WO 6 photocatalyst
featuring both bismuth and oxygen dual vacancies (V Bi+O -BWO). The oxygen vacancies trap photogenerated electrons for N 2 activation, while bismuth vacancies enhance H 2 O adsorption and facilitate proton generation. Through this synergistic
effect, the photocatalytic nitrogen reduction performance was significantly
enhanced. Experimental results show that V Bi+O -BWO achieves
an ammonia production rate of 113.14 μmol·g –1 ·h –1 , a 4.9-fold enhancement over the unmodified
catalyst. N 2 -TPD results demonstrate that the dual vacancies
effectively enhance N 2 chemisorption, facilitating subsequent
activation. In situ FTIR confirms that N 2 adsorbs and converts
on Bi 2 WO 6 via a distal pathway. This study provides
new insights into the development of high-efficiency dual-vacancy
photocatalytic materials.
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PubMed
高影响因子
CHEMICAL PHYSICS
·
2026
·
IF 2.8
Haoming Huang,Xi Wang,Xiaohui Zhang,Chenghang Li,Jing Zhang,Shan Qing,Zhumei Luo
TiO 2 /H 2 O NFs exhibit the highest stability at pH = 2 and pH = 12. • Near the IEP, electrostatic repulsion weakens, leading to particle aggregation. • Combined experimental and DLVO theory to analyze TiO 2 /H 2 O NFs stability. • Temperatures above 318 K and proximity to the IEP degrade TiO 2 /H 2 O NFs thermal performance. Nanofluids (NFs) attract attention in heat transfer due to high thermal conductivity, but nanoparticle aggregation limits their performance. Herein, 0.1 wt% TiO 2 /H 2 O NFs were prepared by a two-step method to investigate the effects of pH (2−12) and temperature (293–353 K) on their stability and thermal performance. Stability was highest at pH = 2 and 12, and the isoelectric point (IEP) was located at pH = 6.5. Near the IEP, weakened electrostatic repulsion promoted aggregation, as confirmed by particle size, Brownian-to-settling velocity ratio, and SEM observations. Derjaguin-Landau-Verwey-Overbeek (DLVO) theory showed that the reduced interaction energy barrier near the IEP increased aggregation, which raised relative viscosity, lowered thermal conductivity, and deteriorated the performance enhancement ratio (PER). The best PER values were obtained at pH = 2 and 12, consistent with the enhanced stability away from the IEP. This study provides a basis for optimizing NF stability and thermal performance via pH control for reliable thermal management. Stability and thermal properties of TiO 2 /H 2 O nanofluids at different pH values. Download: Download high-res image (294KB) Download: Download full-size image
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Small
·
2026
·Vol. 22
·期 28
·e73208
·
IF 11.8
Mi Gan,Wenbo Dong,Xiaofei Zhao,Maria Manzoor,Yingxue Xia,Jinzhang Liu
Aqueous rechargeable Zn-organic batteries at discharged state can self-charge through the spontaneous O 2 -oxidation of organic cathode, and the self-charged energy originates from the consumption of Zn anode, as the stripped Zn is converted into complex compounds on cathode surface. These byproducts block ion diffusion and shorten cycle life. Additional drawbacks include the semi-open battery case for air uptake, which leads to electrolyte evaporation, and the low discharge voltage plateau. To address these challenges, herein a triple strategy is presented: (i) The fabrication of a bicomponent organic cathode comprising a polymer and small molecules, achieving a synergistic effect by the regulation of molecular orbital levels; (ii) The incorporation of Pt nanoparticles into the organic blend to modulate redox reactions, thereby enhancing capacity and enabling self-charging capability based on proton chemistry, without the O 2 -oxidation mechanism; (iii) The implementation of an electrolyte decoupling strategy, which not only elevates the self-charged voltage to 2.1 V but also prevents byproduct formation on cathode surface. The hermetically sealed cell can self-charge to generate power by consuming the Zn anode. The role of Pt nanocatalyst in augmenting capacity and self-charging performance is investigated both experimentally and theoretically. Furthermore, practical applications of this self-charging battery are vividly demonstrated.
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ENERGY & FUELS
·
2025
·
IF 5.3
Liangliang Ren,Lixia Zhang,Tie Geng,Jiayu Sun,Xuejian Liu,Botao Xu,Huaike Li,Lei Guo,Zhenyuan Yin
With the global demand for carbon reduction, hydrate-based CO2 sequestration evolves as a promising technology for offshore CO2 storage. However, the slow kinetics of CO2 hydrate formation, primarily due to the limited contact area and mass-transfer resistance between immiscible liquid CO2 and the H2O phases under high pressures, remain a critical bottleneck for its practical application. To this end, we proposed a CO2-in-water (C/W) emulsion system by employing a nonionic surfactant, alkyl polyglucoside (APG), using simple high-speed stirring. We systematically examined how the degree of mixing, i.e., stirring rate, impacts the stability of the C/W emulsion and the subsequent CO2 hydrate formation kinetics. Using a full-visual reactor coupled with an in-house developed phase identification algorithm, C/W emulsification and demulsification kinetics were unveiled. C/W emulsion stability under various high stirring rates and APG concentrations was examined. We further demonstrate the superior CO2 gas uptake and rapid CO2 hydrate formation kinetics realized by the synthesized stable C/W emulsion. Our results suggest that increasing the stirring rate substantially speeds up the C/W emulsification synthesis process, achieving only 9 s at an optimal stirring rate of 1600 rpm and 3.00 wt% APG. The stability of C/W emulsion is further enhanced under high shearing rate, with complete demulsification time reaching 5 h. Furthermore, increasing the stirring rate from 800 to 1600 rpm not only improves the C/W emulsion stability but also results in shortened induction time, high CO2 hydrate formation kinetics, and high CO2 final uptake (maximum gas uptake 167.7 v/v with a water conversion of 84.5%). The experimental results provide direct evidence on how the stirring rate affects C/W emulsion preparation and stability. The findings also shed light on a promising emulsion-based method for effective CO2 hydrate formation kinetics promotion, which can be adopted in a series of CO2 hydrate-based applications.
研究领域:
化学工程
·
环境科学
·
能源技术
·
物理化学
·
碳捕集与封存（CCS）
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2020
·
IF 2.369
Lijiang Guo,Hongxia Li
The solubility of the RbCl–CsCl–H2O ternary system has been investigated at the temperature range from 298.15 to 348.15 K by two different methods, namely, the Flow-Cloud-Point (FCP) method and the Isothermal Dissolve Equilibrium (IDE) method. The measured solubility for this ternary system at 298.15 K by FCP method is consistent with the reported result in literature. The measured solubility results for this ternary system at 323.15 K by the FCP and IDE, two different methods that are consistent with each other, which indicated the results are more reliable. Meanwhile, the measured liquid–wet solid–solid lines proved that the equilibrium solid phases are two types of solid solutions (Rb,Cs)Cl(ss) and (Cs,Rb)Cl(ss) rather than pure salts (RbCl and CsCl) reported in literature. For the first time, the solubility of the RbCl–CsCl–H2O ternary system at 308.15 and 348.15 K has been measured by IDE method. The measured results shown that the equilibrated solid phases in this ternary system at 308.15 and 348.15 K are two types of solid solution (Rb,Cs)Cl(ss) and (Cs,Rb)Cl(ss), at RbCl rich side and CsCl rich side, respectively.
研究领域:
无机化学
·
溶液热力学
·
物理化学
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高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2020
·Vol. 96
·期 5
·1176-1186
·
IF 2.75
Meng Zhang,Yu-Jie Weng,Yu-Qing Zhang
BACKGROUND Silk fibroin has attracted extensive attention due to its useful biological properties. However, in the regeneration process of silk fibroin, the need for highly concentrated neutral salt dissolution and long-term dialysis greatly hinder the development of silk biomaterials. RESULTS A 3-fold volume of isopropanol (IP) was added to one volume of 20% (w/v) silk fibroin solution dissolved in a CaCl 2 -EtOH-H 2 O ternary system (SFTS) to extract the protein. The extraction resulted in the precipitate consisted of aggregated silk fibroin in the SFTS. The extracted protein was easily resolubilised in water. Compared with the original dialysis time required for the SFTS, the dialysis time of the extracted protein was shortened by nearly half. When the SFTS was diluted with a 2.5-fold volume of water, the same IP extraction resulted in the dialysis time being shortened by two thirds. SDS-PAGE showed that IP extraction did not cause breakage of the silk peptide chain. FTIR and X-ray diffraction indicated this extraction had no influence on the secondary structure of silk fibroin. CONCLUSION Excess IP extraction effectively accelerates the desalting and purification of fibroin in a CaCl 2 -EtOH-H 2 O ternary system without affecting the protein structure, thus greatly improving the regeneration efficiency of silk fibroin. © 2020 Society of Chemical Industry
研究领域:
材料科学
·
生物化学
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2023
·
IF 2.6
Qing Hao,Huan Zhou,Jing Yu Chang,Jie Li,Yun Zhao
Brine deposited in Chaerhan salt lake belongs to the chloride type and can be simplified into the hexnary system Li+, Na+, K+, Mg2+, Ca2+, Cl––H2O. The known solubility data indicate that significant salting-in effects exist in its subsystems of KCl–LiCl–H2O and KCl–CaCl2–H2O, which inevitably affect the properties and solubility behavior of actual brine. In this work, the solubility behavior study and phase diagram determination are extended to the quaternary system of Li+, K+, and Ca2+∥Cl––H2O. The phase equilibrium data at 298.15 and 273.15 K are reported, and five solid species, including two double salts KCl·CaCl2 and LiCl·CaCl2·5H2O, are found. The salting-in effect is still exhibited in the Li+, K+, and Ca2+∥Cl––H2O system and results in a very high total salt content at invariant points; e.g., they are 59.08 and 46.93% at 298.15 and 273.15 K, respectively.
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高影响因子
IONICS
·
2023
·Vol. 29
·期 4
·1479-1486
·
IF 2.8
Liu Yang,Chen Han,Lou Xiaoming,Wen Xiaoyu,Yin Zhenguo,Xiang Kaixiong
Rechargeable aqueous ammonium-ion batteries (AAIBs) have attracted more and more attention in energy storage devices because of great safety and cost-effectiveness, as well as excellent rate capability. Recently, it is the main exploration focus for the further improvement of AAIBs to develop suitable electrode materials. Herein, titanic acid and TiO 2 were simply synthesized by the facile co-precipitation approach. Titanic acid showed higher capacity of 104.5 mAh g −1 at the 0.1 A g −1 current density, and higher cyclability with the 91.2% capacity retention cycled 1000 cycles at 1 A g −1 . Titanic acid is promising as aqueous ammonium-ion batteries with great stability and capacity.
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Meiling Tang,Xiaoqi Yi,Haiming Huang,Yingli Feng,Gang Chen,Xiaojing Mu
Aqueous biphasic system (ABS) for extraction of active components attracted increasing attention due to advantages of high extraction efficiency and high product purity. However, solvent factors ruling extraction is still unclear. Four new ABSs with different organic solvent were designed for paeonol extraction, and the extraction conditions such as NaH 2 PO 4 concentration, organic solvent fraction, extraction period and temperature were examined with single factor method. The paeonol extraction yield, partition coefficient and paeonol purity with ABSs at optimized conditions were in the order as follows: ABS-THF-EA (33.6 ± 1.5 mg/g) ≈ABS-Ac-EA (33.0 ± 1.3 mg/g) > ABS-EtOH-EA (31.6 ± 1.6 mg/g)≈70 % ethanol (v/v) (31.2 ± 1.4 mg/g) > ABS-THF (28.8 ± 1.0 mg/g) > ABS-Ac (27.6 ± 1.2 mg/g) > ABS-EtOH (25.2 ± 1.2 mg/g), suggesting that replacing fraction of acetone/THF with ethyl acetate (EA) in ABSs could improve paeonol yield. Compositions and solvatochromic parameters for top phase of 12 ABSs were detected. Using LSER model, paeonol yield was strongly correlated to the dipolarity/dipolarizability (π*), hydrogen bond acidity (α) and hydrogen bond basicity (β) of top-phase medium in ABS ( r 2 = 0.982, n = 12); and partition coefficient was reasonably correlated to π*, α and β ( r 2 = 0.942, n = 12). Hydrogen-bond interaction and hydrophobicity interaction between paeonol and top-phase medium were crucial for efficient extraction. Solvatochromic parameters can offer guidance to solvent selection in extraction with ABS.
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