查找使用阿拉丁产品的科研文献

Caterpillar-like Ag–ZnO–C hollow nanocomposites for efficient solar photocatalytic degradation and disinfection

Ying Liu,Yucai Wan,Chuncai Kong,Pan Cheng,Qin Cheng,Qiongzhen Liu,Ke Liu,Ming Xia,Qihao Guo,Dong Wang

Engineering a highly accessible semiconductor with optimized physicochemical structure for efficient photocatalysis under visible light is never-ending. Herein, a facile route was developed to fabricate a caterpillar-like ZnO–C (ZC) hollow nanocomposite by directly pyrolyzing Zn-BTC MOF microrods and nanorods, which have been previously synthesized via a rapid supersonic-assisted aqueous reaction at room temperature. It is demonstrated that the ZC nanorods radically grow on the surface of the hollow nanocomposite directly converted from MOF-microrods at 550 °C and form a caterpillar-like catalyst based on an oriented attachment mechanism. After in situ photo-reduction of AgNO3, the Ag–ZnO–C (AZC550) nanocomposite catalyst possesses ultrahigh photodegradation turnover frequency (TOF) values towards methyl blue (3.00 × 10−3 mol mol−1 min−1), 4-nitrophenol (0.14 × 10−3 mol mol−1 min−1) and amoxicillin (3.43 × 10−3 mol mol−1 min−1), as well as a photo-inactivation activity of 6.25 × 105 cfu mg−1 min−1 towards E. coli, outperforming most state-of-the-art catalysts reported thus far. The ameliorated photocatalytic performance and recyclability can be assigned to the synergistic effects between the Zn–C hierarchical nanoarchitecture and Ag-NPs. This work provides a new approach for the design of efficient solar photocatalysts.

Effect of the Ag+ in Ag25@ZnO nanocatalysts for the 4-nitrophenol reduction reactions

Ji Xiang,Chuancui Yang,Ke Yang,Jin Qian,Yanzhen Lu,Qihua Zhou,Fangkuo Wang

As catalysts, metal nanoclusters (NCs) have become the focus of research due to their precise structure and excellent catalytic activity. In general, it can greatly improve the catalytic activity of NCs by thermal treatment. In this work, the ZnO supported 2,4-dimethylbenzenethiol-protected-[Ag 25 (C 8 H 9 S) 18 ] - NCs (Ag 25 @ZnO) nanocatalysts were subjected to activation temperatures of 100 °C, 200 °C and 300 °C to remove the surface ligands of Ag 25  NCs and regulate the surface composition of Ag 25 @ZnO nanocatalysts. The structure of Ag 25 @ZnO nanocatalysts were characterized by XRD , SEM, TEM, EDS and XPS. In particular, the XPS results obviously confirmed that the concentration of Ag + on the catalyst surface was positively correlated with the activation temperature. Finally, the effect of the Ag  +  content on the catalytic activity of the Ag 25 @ZnO nanocatalysts was also explored. Because the content of Ag + in Ag 25 @ZnO-300 nanocatalysts is the highest, the 4-nitrophenol reduction reaction showed the best catalytic performance.

Fabrication and Sintering Behavior of Nano Cu–Ag Composite Paste for High-Power Device

Weishan Lv,Jiaxin Liu,Yun Mou,Yongjie Ding,Mingxiang Chen,Fulong Zhu

Coordination-Driven One-Step Rapid Self-Assembly Synthesis of Dual-Functional Ag@Pt Nanozyme

Zaihui Du,Longjiao Zhu,Pengfei Wang,Xinyue Lan,Shenghao Lin,Wentao Xu

Realizing high-precise and adjustable regulation of engineering nanozyme is important in nanotechnology. Here, Ag@Pt nanozymes with excellent peroxidase-like and antibacterial effects are designed and synthesized by nucleic acid and metal ions coordination-driven one-step rapid self-assembly. The adjustable NA-Ag@Pt nanozyme is synthesized within 4 min using single-stranded nucleic acid as templates, and peroxidase-like enhancing FNA-Ag@Pt nanozyme is received by regulating functional nucleic acids (FNA) based on NA-Ag@Pt nanozyme. Both Ag@Pt nanozymes that are developed not only has simple and general synthesis approaches, but also can produce artificial precise adjustment and possess dual-functional. Moreover, when lead ion-specific aptamers as FNA are introduced to NA-Ag@Pt nanozyme, the Pb 2+ aptasensor is successfully constructed by increasing electron conversion efficiency and improving the specificity of nanozyme. In addition, both nanozyme has good antibacterial properties, with ~100% and ~85% antibacterial efficiency against Escherichia coli and Staphylococcus aureus , respectively. This work provides a synthesis method of novelty dual-functional Ag@Pt nanozymes and successful application in metal ions detection and antibacterial agents.

Construction and Tribological Performance of Ag Nanowire-Dotted 2D Ni-BDC Nanocomposites in Oil

Huawen Zhu,Zhilin Cheng

The collaborative lubrication effect based on different lubricating nanostructures could not only overcome the respective drawbacks of different nanostructures as nanoadditives but also comprehensively improve friction performance. For this, we first developed a novel collaborative lubrication nanostructure based on Ag nanowires (NWs) and two-dimensional (2D) Ni-BDC nanosheets (Ag NWs/2D Ni-BDC) by the in situ chemical reduction strategy. The structural characterizations corroborated that Ag NWs with a width of approximately 20–30 nm grew on the surface of 2D Ni-BDC nanosheets, which presented the chemical interface between both. As the nanoadditive applied in oils, the tribological finding confirmed that the Ag NWs/2D Ni-BDC enabled the friction coefficient and wear scar diameter to reduce by 38 and 37% at 0.04 wt % additive content, respectively. The worn surface was characterized by a series of analytical techniques, which basically revealed the friction-reducing and antiwear mechanism based on the layered structure and self-repair effect. Consequently, the nanocomposite structure incorporating the nanowire and 2D nanosheets should be taken into account as a new potential lubricating material.

Highly efficient sunlight-driven LSPR-enhanced core-shell Ag dendrite/g-C3N4 composite photocatalysts

Yuan Li,Wenyao Qian,Yong Xia,Xinxin Li,Dongmei Li,Zhiqiang Guo

Noble metal nanostructures with localized surface plasmon resonance (LSPR) effect can be employed to enhance the light absorption ability of photocatalysts . However, it has been a challenge to control the size and morphology of noble metal nanostructures to manipulate the LSPR wavelength and improve the performance of photocatalysts. Herein, an Ag dendrite (AgD) composed of Ag nanorods with different sizes was facilely constructed by a displacement reaction, and sunlight-driven LSPR-enhanced core-shell AgD/g-C 3 N 4 composite photocatalysts (AgD-CN) were synthesized by thermal polymerizing mixtures of melamine and different amounts of AgD. This core-shell AgD-CN improved the stability of AgD and made full use of the near-field enhancement effect of AgD’s LSPR, resulting in a broad light absorption band. AgD-CN-15 showed the highest photogenerated electron-hole pair separation rate and the best photocatalytic performance when the addition amount of AgD was 3 wt%. The degradation rate of RhB by AgD-CN-15 reached 95.20% after sunlight irradiation for 60 min, and its reaction rate constant was 5.2 times that of the pristine g-C 3 N 4 . Moreover, ·OH, h + and ·O 2 - were found to be the main active species. AgD is easy to prepare and can broaden the light absorption wavelength range and significantly enhance light absorption ability of photocatalysts, which provides a new method to improve the performance of LSPR-enhanced photocatalysts.

High-Index-Faceted Cu Nanoparticles in Ag–Cu Tandem Catalysts for Selective CO2 Electroreduction

Guangtao Wang,Simin Li,Chao Yu,Yang Zhou,Wenlei Zhu,Bo Shen

Abstract Facet engineering of Cu-based nanocatalysts is a promising strategy for regulating the selectivity of CO2 and CO electroreduction because surface atomic arrangements strongly influence intermediate adsorption and reaction pathways. Compared with low-index facets, high-index facets contain abundant steps, kinks, and low-coordinated atoms, providing diverse active ensembles that can facilitate CO adsorption and subsequent C–C coupling. However, the catalytic roles of high-index-faceted Cu nanocatalysts remain largely unexplored. Herein, tetrahexahedral (THH) and hexoctahedral (HOH) high-index-faceted Cu nanoparticles were integrated with a porous Ag foam to construct Cu/Ag tandem catalysts for CO2 electroreduction. The C2+ selectivity follows the order HOH Cu/Ag > THH Cu/Ag > non-facet-controlled Cu/Ag, with HOH Cu/Ag achieving the highest ethylene Faradaic efficiency of 60.37%. In situ spectroscopic measurements using HOH Cu/Ag as a representative high-index-faceted catalyst indicate the formation of abundant adsorbed CO and possible CO-derived coupling intermediates within the potential range associated with pronounced ethylene production. Stability measurements further show that the morphology and catalytic selectivity are largely retained under moderate operating conditions, whereas more negative potentials induce surface roughening and gradual performance decay. This work provides a platform for investigating morphology-dependent selectivity in high-index-faceted Cu catalysts during CO2 electroreduction.

Facile synthesis of Ag lattice doped mesoporous In2O3 nanocubes for high performance ethanol sensing

Xinyu Liu,Cuiping Jia,Xin liu,Jiabing Luo,Yan Zhou,Wenle Li,Shutao Wang,Jun Zhang

Ag lattice doped In2O3 with a mesoporous structure was synthesized through a combination of hydrothermal and calcination methods. The structural and morphological characteristics were assessed using XRD, SEM, TEM, TGA, BET, and XPS analyses. Gas sensing measurements revealed that the 7.0 mol% Ag-doped In2O3 sensor displayed a response of 420 towards 100 ppm ethanol at 140 °C, which was 19 times higher than that of the pure In2O3 gas sensor. Density functional theory calculations indicated that Ag-doped In2O3 exhibited enhanced adsorption performance, higher adsorption energy, and electron transfer, resulting in higher sensitivity to ethanol. These findings were also supported by the electronic band structure, work function, and DOS analyses. These results indicated that the Ag doped mesoporous In2O3 has high potential for the preparation of high-performance ethanol sensors in practical applications.

The Effect of Anion Modification on the Conductive Polymer/Ag-Interdigitated Electrodes Micro-Supercapacitor

Kai Shi,Guangming Zhang,Zhifeng Han,Lingxuan Ma,Jiaqi Hou,Daosen Song,Zhiguo Fu,Wei Zhou,Chenxu Guo,Huifa Shi,Xiaoyang Zhu,Hongbo Lan

Due to their outstanding electrical conductivity, simplicity of synthesis, and exceptional flexibility, conductive polymers are the most attractive electrode materials for micro-supercapacitors (MSCs). However, when used as an electrode material alone, its poor capacitive performance and cycle-life hinder the wide engineering applications. Herein, a polypyrrole (PPy)/Ag-interdigitated electrodes MSCs is proposed, and the impact of aromatic sulfonic acid group anion modification on the electrochemical properties and flexibility of PPy/Ag MSCs is investigated. In the results, it is shown that different aromatic sulfonic-acid-based anionic dopants have different effects on the properties of PPy films. Among the prepared three PPy/Ag MSCs devices, PPy:anthraquinone-2-sulfonic acid/Ag MSCs have the highest areal capacitance (198.8 mF cm −2 ) at a current density of 0.5 mA cm −2 , surpassing PPy:2-naphthalenesulfonic acid/Ag MSCs (114.3 mF cm −2 ) and PPy:p-toluenesulfonic acid monohydrate/Ag MSCs (89.7 mF cm −2 ). Furthermore, at a power density of 0.25 mW cm −2 , the PPy:AQS/Ag MSCs exhibit a high energy density of 27.61 μWh cm −2 , which is above the most of the previously reported PPy-based MSCs. Therefore, in this research, the groundwork is provided for improving properties of flexible MSCs based on PPy.

Preparation and Tribological Behavior of Nitrogen-Doped Carbon Nanotube/Ag Nanocomposites as Lubricant Additives

Shaokun Jia,Jiahuan Zhao,Guangzhen Hao,Jifeng Feng,Chuanbo Zhang,Zhihui Wang,Zhengfeng Jia,Yungang Bai

In this study, nitrogen-doped carbon nanotube/Ag nanocomposites (denoted as N-C/Ag) have been synthesized in a urea solution using a hydrothermal method. The carbon nanotubes, AgNO3solution, urea and poly-dopamine (PDA) served as carbon, silver, nitrogen and carbon sources, respectively. The results show that the diameter of the carbon tubes was about 30 nm, and the Ag nanoparticles, with a diameter of ca. 10 nm, dispersed on the carbon tube surface. The Ag particle size decreased with a lower degree of crystallinity at a high temperature in the presence of urea. The friction and wear behavior of the oil acid (OA) modified N-C/Ag (OAN-C/Ag) as an additive in liquid paraffin (LP) were studied using a four-ball friction and wear tester. The results have shown that the coefficients of friction (COFs) and wear scar diameters (WSDs) of steel balls lubricated with LP-OAN-C/Ag decreased by 27.3% and 25.3%, respectively, relative to pure LP. Tribofilms containing Ag, carbon and nitride were formed on the worn steel ball surfaces. Details, the carbon, Fe2O3, azides and nitride, Ag and alloy and other compounds on the wear scars may improve tribological properties. The synergistic effect of carbon, Ag and urea plays a critical role during sliding.Keywords:N-doped carbon nanotube/Ag nanocomposites;polydopamine;hydrothermal;wear;friction

Ag-Coated Ternary Layered Double Hydroxide as a High-Performance SERS Sensor for Aldehydes

Xiangyu Meng,Yuening Wang,Xiaoyu Song,Mingjian Zhang,Jian Yu,Lin Qiu,Jie Lin,Xiaotian Wang

Volatile organic compounds (VOCs) are common environmental pollutants and important biomarkers for early diagnosis of lung cancer. However, aldehydes are difficult to detect directly due to their small Raman scattering cross-section and gaseous phase. Here, a Ag-coated ternary layered double hydroxide (LDH) was designed for the detection and identification of various aldehydes. The specific surface area of CoNi-LDH was increased by doping Fe3+, which provides abundant active sites to capture gas molecules. Furthermore, the energy band gap (Eg) was decreased due to the local amorphous FeCoNi-LDH with an extended band tail, promoting the excitonic transition of Fe0.07(CoNi)0.93-LDH. In addition, the Fermi level of Ag prevented the recombination of electron–hole pairs of Fe0.07(CoNi)0.93-LDH, providing a new bridge for charge transfer between the substrate and the molecule. Ag/Fe0.07(CoNi)0.93-LDH presented excellent surface-enhanced Raman scattering (SERS) performance for aldehyde VOCs by modification with 4-aminothiophenol (4-ATP) to capture aldehydes and realized the detection of benzaldehyde (BZA) at 10 ppb. The enhancement and Raman shift of the b2 mode indicated the contribution of chemical enhancement to the SERS system, so the substrate presented good uniformity. The recycling of the SERS substrate is realized based on the reversibility of the Schiff base reaction. These results manifested that Ag/FeCoNi-LDH has a wide prospect in the application in the trace detection of aldehydes.

Asymmetric and Flexible Ag-MXene/ANFs Composite Papers for Electromagnetic Shielding and Thermal Management

Xiaoai Ye,Xu Zhang,Xinsheng Zhou,Guigen Wang

Lightweight, flexible, and electrically conductive thin films with high electromagnetic interference (EMI) shielding effectiveness and excellent thermal management capability are ideal for portable and flexible electronic devices. Herein, the asymmetric and multilayered structure Ag-MXene/ANFs composite papers (AMAGM) were fabricated based on Ag-MXene hybrids and aramid nanofibers (ANFs) via a self-reduction and alternating vacuum-assisted filtration process. The resultant AMAGM composite papers exhibit high electrical conductivity of 248,120 S m−1, excellent mechanical properties with tensile strength of 124.21 MPa and fracture strain of 4.98%, superior EMI shielding effectiveness (62 dB), ultra-high EMI SE/t (11,923 dB cm2g−1) and outstanding EMI SE reliability as high as 96.1% even after 5000 cycles of bending deformation benefiting from the unique structure and the 3D network at a thickness of 34 μm. Asymmetric structures play an important role in regulating reflection and absorption of electromagnetic waves. In addition, the multifunctional nanocomposite papers reveal outstanding thermal management performances such as ultrafast thermal response, high heating temperatures at low operation voltage, and high heating stability. The results indicate that the AMAGM composite papers have excellent potential for high-integration electromagnetic shielding, wearable electronics, artificial intelligence, and high-performance heating devices.Keywords:Ag-MXene/ANFs nanocomposite papers;asymmetric structure;EMI shielding;Joule heating performance