NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 19
·9075-9084
·
IF 3.925
Yanping Li,Ya Liu,Li Wang,Hongsheng Lu
Polyacrylamide and its derivatives are widely used in oilfields due to their efficient viscosity building and drag-reducing properties. At present, the commonly used products of polyacrylamide include two types: polymer powder and polymer emulsions. However, the low dissolution rate of powdered products and the instability of polymer emulsions limit their application. Here, we constructed a pH-sensitive inverse polymer emulsion of poly(acrylamide-co-acrylic acid-co-2-acrylamide-2-methylpropyl sulfonic acid), showing a phase separation and phase inversion from W/O to O/W at pH < 6 and pH > 8 due to a pH-switchable surfactant N,N-dimethylcyclohexylamine/Oleic acid complex (DM–OA). The demulsification or phase inversion of the W/O polymer emulsion can release the polymer that was originally in the aqueous phase, and the released polymer can quickly dissolve in water to perform its function of viscosity building and friction reduction. Therefore, this pH-sensitive modified-polyacrylamide polymer emulsion shows a fast dissolution rate with a dissolution time of about 1 min and a long storage stability. The utilization of stimuli-responsive surfactants to construct pH-responsive water-soluble polymer W/O emulsions provides a new approach to the preparation of water-soluble polymer emulsion additives that can be quickly dissolved and stored for long periods of time in water-treatment, papermaking and oil recovery fields.
研究领域:
石油工程
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材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2013
·
IF 5.437
Kai Yan,Rui Wang,Jingdong Zhang
A novel photoelectrochemical (PEC) biosensing platform was constructed by assembling CdSe quantum dots (QDs) and DNA on liquid phase deposited TiO 2 (DNA–CdSe/TiO 2 ) film electrode. The transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis indicated that CdSe QDs were homogeneously assembled on TiO 2 film. The UV–visible diffuse reflectance spectra (DRS) showed that CdSe and DNA could effectively enhance the absorption of TiO 2 film to visible light. The obtained electrode showed a sensitive PEC response to o -aminophenol (OAP) under visible light irradiation . Due to the interaction between DNA and OAP, the response of OAP was improved by DNA immobilized on the sensing film. Under optimized conditions, the photocurrent was linearly proportional to OAP in the concentration range from 4.0×10 −7 to 2.7×10 −5 mol L −1 , with a detection limit (3 S/N) of 8.0×10 −8 mol L −1 . The novel strategy could provide a fast and sensitive method for OAP determination.
研究领域:
生物传感技术
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材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Zongli Liu,Tian Wang,Pu Chang,Lixiu Guan,Xiaohu Wang,Chao Xu,Yingxuan Cao,Junguang Tao
Although electrocatalytic water splitting is a very promising and sustainable method for generating hydrogen as a clean energy source, the design and synthesis of stable and efficient noble metal-free catalysts faces some serious challenges. In this work, an electrocatalyst with heterostructure of MoS 2 and orthogonal phase of CoSe 2 (MoS 2 @o-CoSe 2 ) is derived from Co-based metal organic framework (Co-MOF). The complex shows excellent hydrogen evolution reaction (HER) activity and long-term stability in alkaline medium attributed to its porous structure , ultrathin nanosheet morphology, synergistic effect of each component owing to the tightly bonded interface and optimal electronic structure after phase transition. MoS 2 @o-CoSe 2 exhibits low overpotential of 34 mV at a current density of 10 mA cm −2 and a Tafel slope of 41 mV dec −1 . These results are superior to most recently reported Mo-based and Co-based electrocatalysts. Importantly, the performance of MoS 2 @o-CoSe 2 at high current densities is even better than that of commercial Pt/C electrode. Our results emphasize the importance of phase engineering and show that the combination of MOF with transition metal disulfides is an effective way to develop highly active and sustainable efficient electrocatalysts for water hydrolysis.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2016
·Vol. 6
·期 1
·1-12
·
IF 5.228
Xie Yinghao,Wu Fangfang,Sun Xiaoqin,Chen Hongmei,Lv Meilin,Ni Shuang,Liu Gang,Xu Xiaoxiang
Wurtzite solid solutions between GaN and ZnO highlight an intriguing paradigm for water splitting into hydrogen and oxygen using solar energy. However, large composition discrepancy often occurs inside the compound owing to the volatile nature of Zn, thereby prescribing rigorous terms on synthetic conditions. Here we demonstrate the merits of constituting quinary Zn-Ga-Ge-N-O solid solutions by introducing Ge into the wurtzite framework. The presence of Ge not only mitigates the vaporization of Zn but also strongly promotes particle crystallization. Synthetic details for these quinary compounds were systematically explored and their photocatalytic properties were thoroughly investigated. Proper starting molar ratios of Zn/Ga/Ge are of primary importance for single phase formation, high particle crystallinity and good photocatalytic performance. Efficient photocatalytic hydrogen and oxygen production from water were achieved for these quinary solid solutions which is strongly correlated with Ge content in the structure. Apparent quantum efficiency for optimized sample approaches 1.01% for hydrogen production and 1.14% for oxygen production. Theoretical calculation reveals the critical role of Zn for the band gap reduction in these solid solutions and their superior photocatalytic acitivity can be understood by the preservation of Zn in the structure as well as a good crystallinity after introducing Ge.
研究领域:
材料科学
·
光催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2024
·
IF 5.6
Ruotong Cui,Wenlong Xu,Feng Liu,Lei Yu,Jiming Liu,Xi Chen,Yingyun Qiao,Yuanyu Tian
The structure and reactivity of coal is the core problem of coal chemistry, and solving it at the molecular level has been an international unsolved problem. The chemical similarity-based coal chemistry group elevates the study from the macroscopic to the molecular level. However, the previous free radical mechanism lacks experimental confirmation and theoretical computational support. Here, the pyrolysis products of model compounds are first utilized to predict pyrolysis. The hydrogen-donating solvent is then used as a radical trap to confirm the reaction. Subsequently, density functional theory calculations are utilized to aid in the validation. Finally, family components are utilized to demonstrate the universality of the free radical mechanism of coal pyrolysis. This work combines radical trapping with quantum chemical calculations to analyze the radical reaction mechanism of coal pyrolysis in depth at the molecular level. This will provide a theoretical basis for coal pyrolysis and clean and efficient utilization.
研究领域:
煤化学
·
量子化学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2024
·
IF 1.7
Lin Guangqiang,Mao Chunfeng,Li Menghua,Wang Ziyi,Li Qinyi,Zhan Jiaqing,Liu Junsheng
In this study, Zn–W–Bi–O catalysts with a sandwich structure were prepared by mixing zinc tungstate and bismuth nitrate to form bismuth tungstate at the interface. The catalyst was composed of bismuth nitrate as the upper layer, zinc tungstate as the lower layer, and phase interface (bismuth tungstate) as the core. The generation of phase interfaces provides a new reaction mechanism for catalytic processes. Based on the different intermediate state changes in the reaction process, the Zn–W–Bi–O catalysis system can be divided into H-S Mechanism, B-R Mechanism, and P-G Mechanism. These reaction mechanisms will simultaneously react with H 2 O 2 to generate various transition states, which will cooperatively oxidize sulfur atoms to remove them. The structural characteristics and stability of Zn–W–Bi–O catalysts were determined. There are strong stability and catalytic efficiency for Zn–W–Bi–O catalysts. The desulfurization rate can be close to 100% under optimal conditions (Catalyst of 0.02 g, ionic liquids of 0.5 mL, H 2 O 2 of 0.2 mL, model oil of 5 mL, 80 °C). Zn-W-Bi-O-2 catalysts lead to 3 times improvement in ODS activity for the upper layer and 1.25 times improvement in ODS activity for the lower layer. The catalytic reaction mechanism was obtained by the structure-activity relationship.
研究领域:
化学工程
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催化材料
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2024
·
IF 5.3
Wen-luan Xie,Bin Hu,Xiao Yang,Ji Liu,Zhi-mo Fang,Kai Li,Yang-wen Wu,Bing Zhang,Qiang Lu
Phosphoric acid is an effective and widely used catalyst for biomass pyrolysis, with significant catalytic impact on the pyrolytic reactions and product distribution. However, its fundamental catalytic mechanism in lignin pyrolysis remains unclear. In this work, we proposed and investigated three possible H 3 PO 4 -assisted pyrolysis mechanisms, i.e., hydrogen-bond-induced decomposition, phosphoric-acid-assisted hydrogen transfer (H 3 PO 4 -AHT), and phosphorolysis, and carefully discussed them through theoretical calculations, electronic structure analyses, catalytic pyrolysis experiments using the β -O-4 linked lignin model. The results indicated that the H 3 PO 4 -AHT mechanism played a dominant role in lignin catalytic pyrolysis, superior to the other two mechanisms. The phosphoric acid molecule could take advantage of its unsaturated P = O and saturated P −OH groups for hydrogen donation and acceptance in concerted H 3 PO 4 -AHT reactions. Alternatively, it could also participate in concerted intermolecular hydrogen transfer with the active hydroxyl group as a mediator. The C β −O bond cleavage could be significantly enhanced by effectively reducing the tension of the transition state ring, leading to the generation of more phenol and styrene in pyrolysis experiments. Due to the inhibition of hydrogen abstraction, C α −C β breakage of β -O-4 linkage, side chain removal of primary products, etc., the formation of other products in phosphoric acid catalytic pyrolysis of β -O-4 linked lignin was restrained. This H 3 PO 4 -AHT catalytic mechanism was also confirmed to be conductive to tautomerism, elimination, dehydration, α -O-4 linkage fracture, β -1 linkage fracture, and other important decomposition reactions in lignin pyrolysis. The understanding of these mechanisms provides valuable insights into the role of phosphoric acid in lignin pyrolysis and may guide the development of effective biomass catalytic conversion methods.
研究领域:
化学工程
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生物质能
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催化科学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-13
·
IF 16.6
Chen Shiyi,Zhang Shishi,Guo Lei,Pan Lun,Shi Chengxiang,Zhang Xiangwen,Huang Zhen-Feng,Yang Guidong,Zou Ji-Jun
Surface reconstruction generates real active species in electrochemical conditions; rational regulating reconstruction in a targeted manner is the key for constructing highly active catalyst. Herein, we use the high-valence Mo modulated orthorhombic Pr 3 Ir 1− x Mo x O 7 as model to activate lattice oxygen and cations, achieving directional and accelerated surface reconstruction to produce self-terminated Ir‒O bri ‒Mo (O bri represents the bridge oxygen) active species that is highly active for acidic water oxidation. The doped Mo not only contributes to accelerated surface reconstruction due to optimized Ir‒O covalency and more prone dissolution of Pr, but also affords the improved durability resulted from Mo-buffered charge compensation, thereby preventing fierce Ir dissolution and excessive lattice oxygen loss. As such, Ir‒O bri ‒Mo species could be directionally generated, in which the strong Brønsted acidity of O bri induced by remaining Mo assists with the facilitated deprotonation of oxo intermediates, following bridging-oxygen-assisted deprotonation pathway. Consequently, the optimal catalyst exhibits the best activity with an overpotential of 259 mV to reach 10 mA cm geo −2 , 50 mV lower than undoped counterpart, and shows improved stability for over 200 h. This work provides a strategy of directional surface reconstruction to constructing strong Brønsted acid sites in IrO x species, demonstrating the perspective of targeted electrocatalyst fabrication under in situ realistic reaction conditions.
研究领域:
电化学
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材料科学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-10
·
IF 12.121
Tang Hua,Tian Yu-Biao,Cui Hongyan,Li Ren-Zhe,Zhang Xia,Niu Dawen
Site-selective modification of complex molecules allows for rapid accesses to their analogues and derivatives, and, therefore, offers highly valuable opportunities to probe their functions. However, to selectively manipulate one out of many repeatedly occurring functional groups within a substrate represents a grand challenge in chemistry. Yet more demanding is to develop methods in which alterations to the reaction conditions lead to switching of the specific site of reaction. We report herein the development of a Pd/Lewis acid co-catalytic system that achieves not only site-selective, but site-switchable mono- O -allylation of polyols with readily available reagents and catalysts. Through exchanging the Lewis acid additives that recognize specific hydroxyls in a polyol substrate, our system managed to install a versatile allyl group to the target in a site-switchable manner. Our design demonstrates remarkable scope, and is amenable to the direct derivatization of various complex, bioactive natural products.
研究领域:
有机化学
·
催化
·
合成化学
✓ 已验证
DOI
高影响因子
Journal of the Australian Ceramic Society
·
2024
·
IF 1.8
Lin Jia,Wang Shuai,Yang Yihang,Huang Guimei,Wang Jinhuo
In this study, Zr-modified Si-O-C precursor ceramics were prepared using three-dimensional (3D) printing. Ceramic sintering was completed by printing four precursors containing different zirconium acetylacetone contents. Comparative analysis was conducted on the ceramic yield, size shrinkage, mechanical properties, and microstructure. The results showed that the ceramic yield and size shrinkage of the four samples were increased with the increasing zirconium acetylacetone contents. The sample containing 30 wt% zirconium acetylacetone exhibited good compressive performance, with a compressive strength of 50.2 ± 0.6 MPa. Cracks were observed on the surface of samples containing 40 wt% zirconium acetylacetone, while those containing 10, 20, and 30 wt% zirconium acetylacetone were relatively intact. Therefore, a stable Si-Zr-O-C precursor ceramic with good mechanical properties, which can be used for 3D printing, was obtained.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Fuxin Liang,Yulin Wei,Yuhang Du,Fan Yang,Zhe Pang,Junyan Wu,Sai Huang,Honglei Wang,Qinggang Li,Chao Wu,Guopu Shi
This study investigated the catalytic hydrogenation of ethyl nicotinate using Pd/Al 2 O 3 -SiO 2 foam ceramic catalysts prepared via sol-gel impregnation (SI), sol-gel precipitation (SP), precipitation-impregnation (PI), and co-precipitation (CP). We aimed to evaluate the performance and stability of these catalysts as coatings on foam ceramic surfaces in a high-pressure hydrogen reactor at 403 K and 5 MPa. Various physicochemical characterization methods were employed to correlate catalytic performance with physicochemical properties. Results indicated that sol-gel prepared supports had higher specific surface areas, more acidic sites, and better metal-carrier interactions compared to the precipitation method. SEM analyses revealed flatter and smoother coatings from the sol-gel method, while TEM showed uniform Pd distribution with impregnation. Ultimately, the SI method provided the best catalytic performance with a conversion of 86.77 %. The conversion of the substrate remained above 80 % after five cycles.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Hongping Li,Tianxiao Zhu,Yuan Zhang,Jie Yin,Jinrui Zhang,Linhua Zhu,Hua Wei,Huaming Li
Adsorbents with high adsorption capacity and selectivity have long been the pursuit of researchers in the field of adsorptive desulfurization. In this study, a novel single-atom adsorbent comprised of iron (Fe) integrated into C, O co-doped hexagonal boron nitride (Fe-BNCO) has been successfully synthesized. This unique material demonstrates outstanding adsorption capabilities, boasting an adsorption capacity of 49.7 mg S/g and excellent selectivity for adsorptive desulfurization. Notably, this adsorption capacity is 48.6 % higher than that of pure BNCO. The incorporation of the Fe element into boron nitride materials induces a reduction in crystallinity and an increase in specific surface area, resulting in a higher number of available adsorption sites. Combining experimental analysis with theoretical calculations, we propose that the exceptional adsorption performance of Fe-BNCO can be attributed to the formation of S-Fe coordination interaction, while maintaining the existing π-π interactions. This study advances our understanding of adsorbents with high adsorption capacity and selectivity, providing valuable insights for the field of adsorptive desulfurization.
研究领域:
材料科学
·
能源与环境化学
✓ 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）