JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2022
·Vol. 105
·期 1
·237-245
·
IF 2.606
Ma Shiyan,Gao Yan,Wu Liang,Ma Ji,Zhang Hui,Liu Xiang,Kong Lingde,Zhong Wenhong,Liu Hongxi,Chen Qingming,Yang Sheng’an
High temperature coefficient of resistivity (TCR) and magnetoresistance (MR) have been long-pursuing goals for perovskite manganites to be used in infrared detectors and magnetic sensors, etc. Here, a series of La 0.68 Nd 0.04 Ca 0.28 MnO 3 /Ag x composites were prepared by sol–gel method combined with solid-state reaction. The crystal structure, surface morphology, chemical composition, element valence, and electrical transport characterizations of the samples are systematically studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray photoemission spectroscopy (XPS), and four-probe method. XRD spectra reveal that all composites crystallized in orthorhombic perovskite structure. SEM displays that the addition of Ag makes the grain boundary more obvious as compared with the sample without Ag. The EDS results show that specimens contain La, Nd, Ca, Mn, O, and Ag elements without any impurity. The content of Ag visibly affected the ratio of Mn 4+ /(Mn 3+ + Mn 4+ ) in XPS spectra. With the addition of Ag, the TCR and MR of the composites have been significantly improved. To be specific, the sample with x = 0.1 demonstrates high TCR (41.79% K −1 ) and MR (87.44%) at 1 T magnetic field, and the former can reach up to 46.59% K −1 in the absence of a magnetic field.
Graphical abstract
研究领域:
材料科学
·
物理学
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DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2018
·
IF 2.943
Shuai Mao,Rui Bao,Dong Fang,Jianhong Yi
Ag/AgX (X = Cl, Br) plasmonic photocatalysts were synthesized via a facile one-pot ultrasonic spray pyrolysis method, wherein no additional issues such as high pressure, surfactants and reducing agents were required. The structure, morphology, and optical property of the as-prepared photocatalysts was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), ultraviolet–visible light absorption spectra and total organic carbon (TOC). The results showed that Ag/AgX photocatalysts have excellent photocatalytic performance for the photodegradation of methyl orange (MO) and methylene blue (MB) pollutants under visible light illumination, and the photocatalytic activity maintains a high level after seven cycles. Metallic Ag 0 particles nucleate on the surface of AgX uniformly through the thermal decomposition of residual AgNO 3 solution, which enhanced the interaction between Ag 0 and AgX. The outstanding photocatalytic activity benefits from the small size and high dispersion of Ag 0 nanoparticles and the enhanced interaction between Ag 0 and AgX.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Chunpeng Bai,Jingce Bi,Junbiao Wu,Yan Xu,Sebastian Wohlrab,Yide Han,Xia Zhang
In this work, a series of Ag/AgX (X = Cl, Br, I)/g-C 3 N 4 (Ag/AgX/CN) composites were successfully fabricated by an in-situ solid phase method. The morphology and structure, photoluminescence and photoelectrochemical properties of composites were investigated in detail. The as-prepared Ag/AgX/CN composites were used as H 2 evolution photocatalysts under visible-light irradiation with a sacrificial agent . The experimental results revealed that Ag/AgI/CN-4 composite possesses highest-H 2 evolution rate (up to 59.22 μmol g −1 h −1 ) which are approximately 31 times higher than that of pure g-C 3 N 4 (1.94 μmol g −1 h −1 ). In addition, Ag/AgCl/CN-4 and Ag/AgBr/CN-4 composites also present high photocatalytic activities yielding, 26.39 and 18.05 μmol H2 g −1 h −1 , respectively. The enhanced photocatalytic activities of Ag/AgI/CN-4 composite might be attributed to the synergistic effect between Ag/AgI nanoparticles and g-C 3 N 4 and the localized surface plasmon resonance effect of metallic Ag. Moreover, Ag/AgI/CN-4 composite showed excellent recyclability and stability after five cycling photocatalytic tests (about 25 h). Furthermore, the possible photocatalytic mechanism of Ag/AgI/CN composites is proposed.
研究领域:
材料科学
·
光催化技术
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DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Yu Yao,Qianhong Shen,Qifeng Chen,Yanyan He,Libei Jiang,Jie Liu,Yue Li,Xudan Cao,Hui Yang
A silver phosphate (Ag3PO4)/silver (Ag)/silver halide (AgX, X = Cl, Br, or I) ternary composite photocatalysts were prepared by loading Ag nanoparticles on Ag3PO4 tetrapods followed with in situ halogenation. The interface charge transfer behavior in the Ag3PO4/Ag/AgX nanocomposite was studied, and the photocatalytic performance was also evaluated. The results show that the Ag3PO4/Ag/AgI photocatalyst exhibits higher photocatalytic activity than the other two photocatalysts due to the more matched band structure between AgI and Ag3PO4. An internal electric field (IEF) from Ag3PO4 to AgI is formed at the heterogeneous interface, so the photogenerated electrons at the conduction band of AgI can rapidly transfer to the valence band of Ag3PO4 and recombine with photogenerated holes, which is consistent with the S-scheme charge transfer mechanism. Meanwhile, the photogenerated electrons left at the conduction band of Ag3PO4 can transfer to Ag nanoparticles due to the Schottky junction and react with oxygen to produce •O2–, which is proved to be the main active species in the photocatalytic procedure. This tandem junction modulated between the S-scheme heterojunction and Schottky junction promotes the efficient separation of photogenerated carriers, thus significantly increasing the average PL lifetime of electrons by 2.95 times. Therefore, the Ag3PO4/Ag/AgI photocatalyst exhibits excellent photocatalytic activity for the degradation of methylene blue and norfloxacin. The seven consecutive cyclic tests prove the good stability of the photocatalyst, thus showing the application potential in the field of sewage treatment.
研究领域:
环境科学
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材料科学
·
化学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Songrong Cheng,Yingjuan Li,Kaizhao Wang,Qianxu Ye,Kun Dong,Yunzhu Wang,Sufang He,Chunjian Wang,Lingde Kong,Feng Liu,YongQiang Yang,Ji Ma,Qingming Chen,Sheng'an Yang
Polycrystalline manganese oxides exhibit remarkable tunable magnetoresistance (MR) and anisotropic magnetoresistance (AMR), rendering them highly promising for magnetic sensor applications. However, their practical utilization is hindered by two critical challenges: (i) the requirement of high magnetic fields to achieve optimal electromagnetic properties, and (ii) the deviation of the metal-insulator transition temperature (T MI ) from room temperature. In this study, La 0.68 Sm 0.02 Ca 0.3 MnO 3 :Ag x ( x = 0.1–0.4) composites were synthesized via sol–gel and solid-phase methods. Notably, at x = 0.2, exceptional MR and AMR values of 88 % and 123 %, respectively, were achieved near room temperature under a low magnetic field of 1 T. This represents the highest AMR performance reported to date for polycrystalline materials under similar conditions, comparable to thin films. The incorporation of Ag was found to mitigate grain boundary scattering while enhancing interfacial spin polarization, thereby significantly improving MR. The extraordinary AMR is attributed to the anisotropic spin–orbit coupling (SOC) effect. Resistivity data were well–fitted using electron-scattering and small-polaron hopping models, further validating the pivotal role of SOC in enhancing AMR under varying magnetic fields. These findings provide a robust foundation for advancing perovskite manganese oxides in manganite–based device applications.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Yu Chen,Senqin Fan,Jiaojiao Chen,Lei Deng,Zeyi Xiao
A catalytic membrane nanoreactor (CMNR) with Cu–Agx (where x is the millimolar concentration of AgNO3) bimetallic catalysts immobilized in membrane pores has been fabricated via coupling flowing synthesis and replacement reaction. Surface characterization by transmission electron microscopy (TEM) gives obvious evidence of the formation of Cu–Ag bimetallic core–shell nanostructures with Ag islands deposited on the Cu core metal. An apparent high shift phenomenon for the Cu element and a low shift phenomenon for the Ag element was determined by X-ray photoelectron spectroscopy (XPS), indicating a close interaction with the transfer of electron density from the Cu atom to the Ag atom. The hydrogenation catalysis of p-nitrophenol (p-NP) was tested to evaluate the catalytic performance. During the catalytic process, the Cu core acts as an electron-deficient site to adsorb and activate the −NO2 group for p-NP, and the Ag shell is beneficial for enhancing active H spilling to the Cu surface and then performing hydrogenation. A volcano-shaped apparent reaction rate constant can be achieved, which rises initially with the increasing Ag content and subsequently drops with a further increase in the Ag content. The highest value of 1071 min–1 can be achieved for CMNR immobilized with Cu–Ag2 owing to the suitable adsorption activation behavior and the best hydrogen spillover behavior.
研究领域:
材料科学
·
催化化学
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Guangrui Jin,Baoxin Ge,Xinle Hong,Caijin Huang,Jing Tang
Designing efficient photocatalysts for photocatalysis hydrogen production is crucial for advancing green energy technologies. In this work, ZnIn 2 S 4 photocatalyst with an asymmetric Zn-Zn-S unit ring structure and abundant in S vacancies was achieved by precisely tuning the molar mass of the Zn ion source using ethylene glycol as the reaction solvent. Z-type heterojunction was constructed via the electrostatic assembly by combining silver clusters (Ag x @GSH) with ZnIn 2 S 4 to enhance charge separation and photocatalytic activity. The structural transition from S-Zn-S to Zn-Zn-S led to local charge redistribution. Meanwhile, S vacancies acted as electron traps, promoting the charge state change of S in the S H sites and significantly accelerates the hydrogen evolution reaction (HER). The composite catalyst Zn-Vₛ-ZIS/Ag x @GSH exhibited a hydrogen production rate of 18.4 mmol·g −1 ·h −1 , under acidic conditions with lactic acid as the sacrificial agent, which is 3.7 times higher than pristine ZnIn 2 S 4 . Density functional theory (DFT) calculations revealed that the Zn-Zn-S distortion and heterojunction formation synergistically enhanced charge transfer and hydrogen adsorption kinetics. This work provides a novel approach for tailoring ZnIn 2 S 4 -based photocatalysts and provides new insights into the design of high-performance heterojunction systems for solar energy conversion.
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DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 59
·54020-54026
·
IF 3.289
Jikuan Qiu,Yuling Zhao,Huiyong Wang,Guokai Cui,Jianji Wang
Development of new efficient catalytic systems for chemical transformation of CO2 is a very attractive topic in green chemistry. In this work, we studied the synthesis of α-alkylidene cyclic carbonates through the coupling reaction between propargylic alcohols and CO2 with new silver catalysts. It was found that activated carbon supported AgX (X = Br and I) was a simple and efficient catalyst for the carboxylative cyclization of propargyl alcohols with CO2 at atmospheric pressure and room temperature. Nearly 99% yield of the desired product was obtained, and the product could be simply separated through solvent extraction. Moreover, the catalyst could be easily recovered and reused at least ten times without a decrease in the catalytic activity and selectivity. These findings are useful for the development of an environmentally friendly chemical process for the production of α-alkylidene cyclic carbonates.
研究领域:
绿色化学
·
催化化学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2016
·Vol. 18
·期 27
·18219-18226
·
IF 4.449
Weiyin Gao,Chenxin Ran,Minqiang Wang,Le Li,Zhongwang Sun,Xi Yao
Although reduced graphene oxide (rGO)-based photocatalyst composites have been intensively developed during the past few years, the influence of reduction extent of rGO on the photocatalytic performance of the rGO-based composite has virtually not been investigated due to some technical limitations, such as the poor water dispersibility of rGO and low reduction selectivity of the hydrothermal method, which make it difficult to control the reduction extent of rGO in these composites. Herein, we used a facile room-temperature method to synthesize Ag/AgX (X = Cl, Br)/rGO photocatalyst composites as a model to study the effect of reduction extent of rGO on the photocatalytic performance of the photocatalyst. It was found that the photocatalytic activities of both Ag/AgCl/PrGO and Ag/AgBr/PrGO systems had an optimized threshold of the reduction extent of photoreduced GO (PrGO). More importantly, due to the different conductive band values of AgCl and AgBr, the optimized thresholds in the two systems were at different PrGO reduction extents, based on which we proposed that the favorable energy band matching between AgX and PrGO in the two systems played a crucial role in obtaining high photocatalysis performance. Besides, the photocatalytic reaction of the Ag/AgBr based system was confirmed to be a pseudo-second-order kinetics reaction rather than pseudo-first-order kinetics reaction. The new insights presented in this work provided useful information on the design and development of a more sophisticated photocatalyst, and can also be applied to many other applications.
研究领域:
材料科学
·
环境科学
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DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2025
·
IF 26.8
Guilin Bai,Jiangtao Li,Tianyu Lan,Teng Gao,Abdelhamid El-Shaer,Beibei Shao,Baoquan Sun
Harvesting energy from water evaporation through hydrovoltaic devices provides a sustainable approach to electricity generation and decentralized power solutions. However, practical performance remains limited by low-current outputs (<100 nA cm −2 ) and operation restricted to low-ionic-strength conditions (< 10 −3 M ) . Here, dual-function, mesh-structured core–shell Ag/AgX reversible electrodes are developed to construct high-current hydrovoltaic devices operable across diverse ionic environments. The in-situ-formed AgX shell mediates redox-driven interfacial ion-electron transduction, while the Ag core provides high-speed electronic pathways, synergistically promoting the efficient conversion of ionic migration into continuous electron flow. Leveraging the localized charge inversion effect, programmable electrical outputs in both magnitude and polarity are obtained further. By co-designing Ag/AgI electrodes with KI-based electrolytes, this device delivers a record-high current density of 26.0 µA cm −2 sustained over 160 h with power density exceeding 3.9 mW m −2 , ≈260-fold higher current and ≈39-fold greater power than previously reported inert-electrode-based systems. Moreover, the solid-liquid interfacial charge inversion enables tunable ion transport and reconfigurable nanochannel selectivity, realizing programmable outputs over an extensive ionic-concentration window (10 −6 – 10 0 M) and multiple ionic species. This strategy implements versatile energy-sensing systems capable of powering electronics and supporting diversified self-powered monitoring across natural and industrial water sources.
研究领域:
能源材料
·
电化学
·
可持续能源
·
纳米流体学
·
自供能传感器
✓ 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）