Unlocking the door to highly efficient Ag-based nanoparticles catalysts for NaBH4-assisted nitrophenol reduction

Liao, Guangfu; Gong, Yan; Zhong, Liu; Fang, Jiasheng; Zhang, L.; Xu, Zushun; Gao, Haiyang; Fang, Baizeng

doi:10.1007/s12274-019-2441-5

Cited by 131 publications

(71 citation statements)

References 279 publications

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“…Scheme illustration of 4-NP reduction following a multistep reduction process (with rate constant k3) by adsorbed atomic hydrogen formed on Ag NPs surface using borohydride (with rate constant k1) and molecular hydrogen (with rate constant k2), respectively. 14 Herein, we present a comprehensive survey of 4-NP reduction over Ag NPs confined in DMSNs via adjusting the surface microenvironment of catalyst. The experimental results demonstrated that these as-obtained Ag@DMSNs nanocomposites exhibit excellent catalytic activity for reduction of 4-NP to 4-AP under proper alkaline condition.…”

Section: Introductionmentioning

confidence: 99%

Interfacial Hydroxyl Promotes the Reduction of 4-Nitrophenol by Ag-based Catalysts Confined in Dendritic Mesoporous Silica Nanospheres

Shan

Tao

et al. 2021

J. Phys. Chem. C

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It has been widely accepted that decreasing the pH value could enhance the reactivity of 4-Nitrophenol (4-NP) reduction accompanied with the pillage of H2, but excess hydrogen generation is wasteful and easy to lead to safety problems. Herein, we show that, contrast to previously reported results, interfacial adsorbed hydroxyl significantly promotes reduction of 4-NP using Ag-based nanoparticles (NPs) confined in dendritic mesoporous silica nanospheres (Ag@DMSNs) as a model catalyst at medium concentration of sodium hydroxide (NaOH). We provide strong evidences that adsorptive 4-NP and hydroxyl could spatially interact to form an intermediate state through p-p overlapping of O atoms at nanoscale interface of Ag NPs, which leads to electron redistribution and accelerates N=O bonds cleavage, and consequently accelerates the reduction of 4-NP. The findings of this work demonstrate that improving the catalytic performance can be holistically achieved through manipulating the weak interactions between reactant and enthetic species on the molecule level. Introduction: 4-Aminophenol (4-AP), the reduction product of 4-NP, is a potent intermediate for the manufacture of pharmaceuticals and dyes. 1 However, without the catalyst, the hydrogenation of 4-NP to 4-AP by NaBH4 is kinetically restricted due to kinetic barriers resulting from the large potential difference between 4-NP and BH4-. 2 In recent years, noble metal nanoparticles (MNPs) have been discovered to exhibit high catalytic activity for selective reduction of 4-NP in the presence of NaBH4, such as Ag NPs, 3 Au NPs, 4 Pd NPs, 5 and Pt NPs. 6 Among these MNPs catalysts, Ag-based catalysts are distinctive (easy preparation, relatively low cost, less toxicity, high activity and good stability) and have been extensively utilized for 4-NP reduction. 7 However, it should be noted that MNPs catalysts are susceptible to suffer from aggregating due to the Van der Waals forces and high surface free energy. 8 For 4-NP reduction on Ag-based catalysts, the formation of large metal particles largely affects the catalytic activity and reusable performance. Accordingly, silver nanoparticles anchored through organic (such as polymers and DNA) 9 or inorganic (such as glasses, metal oxides and zeolites) 10 templates have been proposed to address the above issues. Among them, dendritic mesoporous silica nanospheres (DMSNs) composed of cage-like spherical nanopores have been confirmed as a unique confinement matrix for the encapsulation of MNPs and enable their application in catalysis. 11 The catalytic performance of MNPs catalysts strongly depends on their microstructure (catalyst composition, exposed crystal face, defect sits, adsorbed species, etc.) and reaction microenvironment (pressure, solvent, pH etc.). Although the reduction of 4-NP is intensively studied as a model reaction, the reaction mechanism is not yet fully comprehended. It is widely accepted that the reduction of 4-NP follows a multistep reduction process and the 4-hydroxylaminophenol (Hx) is a relative stable inte...

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Section: Introductionmentioning

confidence: 99%

Interfacial Hydroxyl Promotes the Reduction of 4-Nitrophenol by Ag-based Catalysts Confined in Dendritic Mesoporous Silica Nanospheres

Shan

Tao

et al. 2021

J. Phys. Chem. C

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“…Except for UV-shielding efficiency, recyclability is equally important for UV-shielding materials [49][50][51][52][53]. To investigate the recyclability of the pure FPI film and FPI/FHBPI-15%, the repeated trials were designed.…”

Section: Uv-shielding Performancementioning

confidence: 99%

Fluorinated Linear Copolyimide Physically Crosslinked with Novel Fluorinated Hyperbranched Polyimide Containing Large Space Volumes for Enhanced Mechanical Properties and UV-Shielding Application

Chen

Guo

et al. 2020

Polymers

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Fluorinated hyperbranched polyimide (FHBPI), a spherical polymer with large space volumes, was developed to enhance fluorinated linear copolyimide (FPI) in terms of mechanical, UV-shielding, and hydrophobic properties via simple blend and thermal imidization methods. FPI possessed superior compatibility with FHBPI, and no obvious phase separation was found. The incorporation of FHBPI led to the formation of physical crosslinked network between FPI and FHBPI, which markedly improved the mechanical properties of the FPI, resulting in maximum enhancement of 83% in tensile strength from 71.7 Mpa of the pure FPI to 131.4 Mpa of the FPI/FHBPI composite film containing 15 wt % of FHBPI. The introduction of FHBPI also changed the surface properties of composites from hydrophilicity to hydrophobicity, which endowed them with outstanding dielectric stability. Meanwhile, the thin FPI/FHBPI composites kept the high transparency in the visible spectrum, simultaneously showing enhanced UV-shielding properties and lifetimes under intense UV ray. This was attributed to the newly formed charge transfer complex (CTC) between FHBPI and FPI. Moreover, the FPI/FHBPI composites possessed preeminent thermal properties. The properties, mentioned above, gave the composites enormous potential for use as UV-shielding coatings in an environment filled with high temperatures and strong ultraviolet rays.

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“…To date, numerous methods have been developed to improve the sensor performance by optimizing the nanomaterials, including carbon nanotubes (CNTs) [1], graphene nanosheets [9], metal nanowires [10][11][12][13][14][15][16][17][18][19], conductive polymers [20], and their composite materials [21][22][23][24][25][26]. Particularly, Ag nanowire (AgNW) has been widely explored as the sensing materials or conductive fillers in pressure sensors because of its excellent electrical properties.…”

Section: Introductionmentioning

confidence: 99%

Ultrasensitive Wearable Pressure Sensors Based on Silver Nanowire-Coated Fabrics

Lian

Wang

et al. 2020

Nanoscale Res Lett

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Flexible pressure sensors have attracted increasing attention due to their potential applications in wearable human health monitoring and care systems. Herein, we present a facile approach for fabricating all-textile-based piezoresistive pressure sensor with integrated Ag nanowire-coated fabrics. It fully takes advantage of the synergistic effect of the fiber/ yarn/fabric multi-level contacts, leading to the ultrahigh sensitivity of 3.24 × 10 5 kPa −1 at 0-10 kPa and 2.16 × 10 4 kPa −1 at 10-100 kPa, respectively. Furthermore, the device achieved a fast response/relaxation time (32/24 ms) and a high stability (> 1000 loading/unloading cycles). Thus, such all-textile pressure sensor with high performance is expected to be applicable in the fields of smart cloths, activity monitoring, and healthcare device.

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Unlocking the door to highly efficient Ag-based nanoparticles catalysts for NaBH4-assisted nitrophenol reduction

Cited by 131 publications

References 279 publications

Interfacial Hydroxyl Promotes the Reduction of 4-Nitrophenol by Ag-based Catalysts Confined in Dendritic Mesoporous Silica Nanospheres

Interfacial Hydroxyl Promotes the Reduction of 4-Nitrophenol by Ag-based Catalysts Confined in Dendritic Mesoporous Silica Nanospheres

Fluorinated Linear Copolyimide Physically Crosslinked with Novel Fluorinated Hyperbranched Polyimide Containing Large Space Volumes for Enhanced Mechanical Properties and UV-Shielding Application

Ultrasensitive Wearable Pressure Sensors Based on Silver Nanowire-Coated Fabrics

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