Deposition Of Ag Nanoparticles Research Articles

Photo-Induced Preparation of Ag@MOF-801 Composite Based Heterogeneous Nanocatalyst for the Production of Biodiesel

Hybrid materials based on metal-organic frameworks (MOFs) and nanoparticles (NPs) have gained considerable popularity in a variety of applications. Particularly, these types of materials have demonstrated excellent efficiency in heterogeneous catalysis due to the synergistic effect between the components. Herein, we report a simple, eco-friendly, photocatalytic method for the fabrication of Zr containing MOF-801 and a silver (Ag) NPs-based hybrid (Ag@MOF-801). In this method, the photocatalytic property of the central metal ion (Zr) of MOF was exploited to promote the formation and deposition of Ag NPs on the surface of the MOF-801 under the irradiation of visible light. The successful incorporation of Ag NPs was ascertained by powder X-ray diffraction (XRD) and UV-Vis analysis, while the morphology and surface area of the sample was determined by N2 adsorption–desorption and scanning electron microscopy (SEM), respectively. The resulting Ag@MOF-801 hybrid served as a highly efficient catalyst for the transesterification of used vegetable oil (UVO) for the production of biodiesel. The Ag@MOF-801 catalyst exhibited superior catalytic activity compared to its pristine MOF-801 counterpart due to the enhanced surface area of the material.

Predicting the Rate Coefficients of Attachment and Detachment of Colloids in Saturated Porous Media

The transport behavior of pathogenic microorganisms and nanoparticles (NPs) in the subsurface is usually studied by performing laboratory soil column experiments. Parameters describing colloid deposition on grain surfaces are estimated by fitting observed breakthrough curves with an appropriate one-dimensional model. However, predictive tools to estimate colloid deposition parameters, knowing the system properties such as soil type, colloid type, solution chemistry, and flow velocity, are useful in estimating the travel distances of pathogenic microorganisms in the subsurface. Such predictive models are rare, except the colloid attachment rate coefficient predicted by colloid filtration theory (CFT) under favorable conditions. Although a couple of theoretical and empirical predictive models are available for estimating the deposition parameters under unfavorable conditions, they were developed for a small set of data, and their applicability to a wide range of conditions is unexplored. In this study, several sets of column-experimental data from literature, covering a wide range of experimental conditions, were analyzed to understand key factors that control colloid deposition. Empirical relationships were developed for deposition rate coefficients and sticking efficiency of various colloidal types [viruses, bacteria, graphene oxide (GO) NPs, silver (Ag) NPs, titanium dioxide (TiO2) NPs, and carboxylate-modified latex (CML) colloids] vis-à-vis 11 physicochemical parameters such as porosity, mean pore-water velocity, median grain size, colloid radius, solution ionic strength, surface potentials of colloids and grains, Hamaker constant, temperature, viscosity of water, and dielectric constant. While deposition of viruses and CML colloids on grain surfaces was found to be reversible, deposition of bacteria, GO NPs, Ag NPs, and TiO2 NPs was found to be irreversible. The empirical equations proposed in this study can predict deposition rate coefficients more closely (p < .001, R2 = 0.69−0.85) than CFT (p < .7, R2 ≤ 0.41). The performance of CFT in predicting the attachment rate coefficients of viruses, bacteria, GO NPs, TiO2 NPs, and CML colloids was found to improve significantly when estimated rate coefficients were multiplied by the sticking efficiency calculated using the empirical expression proposed in this study (p < .001, R2 = 0.65−0.95).

Stretchable and ultrasensitive strain sensor based on a bilayer wrinkle-microcracking mechanism

As a fundamental component for human–machine interaction and human health monitoring, stretchable strain sensors suffer from an irreconcilable trade-off between sensitivity and stretchability. This severely limits their capability to detect both subtle and large deformations simultaneously. Here, a new class of strain sensors is proposed based on a hitherto unexploited strain-sensing bilayer consisting of a pre-wrinkled reduced graphene oxide layer and a highly susceptible layer of conformally deposited Ag nanoparticles. During straining, the pre-wrinkled interlayer guides preferential microcracking at the wavy troughs of the conformal Ag surface-layer, leading to effective integration of the irreconcilable sensitivity and stretchability. The obtained strain sensor not only shows high stretchability, but also owns unprecedented gauge factor (GF) both in subtle and large strain ranges (0–2%, GF: 420; 110–125%, GF: 1.1 × 109), ultralow strain detection limit (0.01%) and ultrafast response (0.13 ms). As demonstrated, the strain sensor has superior capabilities in diverse human motion detection and voice recognition over the whole audible frequency range (20–20000 Hz) with ultrahigh frequency resolution (0.5 Hz). It is expected that the novel wrinkle-directed dynamic patterning/structuring (e.g., microcracking in the current case) involved in the proposed bilayer design can be extended to fabricate a new generation of stretchable sensing devices with unprecedented capabilities.

Enhanced thermal conductivity of silicone rubber via synergistic effects of polydopamine modification and silver deposition on boron nitride

It is great significance to develop polymeric composites with effective heat dissipation and high electrical insulation for devices in electronics fabrication. Herein, we fabricated silicone rubber (SR) composites with large thermal conductivity (TC) and high electrical insulation by utilizing the synergistic effects of polydopamine (PDA) modification and Ag nanoparticles deposition on the surface of BN sheets, denoted as BN-PDA-Ag/SR composites. Finally, the fabricated BN-PDA-Ag/SR composite at a filler content of 30 vol% exhibited a TC up to 0.75 W/(mK), which was about 5.76 times of pure SR, while it holded a low AC conductivity of 1.89 × 10-11 S/cm at 100 Hz. Overall, the synergistic effects of PDA modification and Ag deposition on BN sheets proposed in this work is an easy and eco-friendly avenue for the preparation of high-performance thermally conductive and insulating polymeric composites for advance electronic equipments.

Spray-deposited Ag nanoparticles on micro/nano structured Ti6Al4V surface for enhanced bactericidal property and cytocompatibility

In this study, different surface textures (Diamond, Cylinder, and Sin) have been designed and produced on Ti6Al4V alloys by selective laser melting technology. TiO 2 /Ag composite coatings were prepared on these textures by merging anodic oxidation and spray deposition methods. Tightly arranged TiO 2 nanotubes (TNTs) with tube diameters of about 100 nm are found on the top and lateral sides of the textures. On the bottom of the textures, dense nanopores were found with a pore diameter of about 50 nm. Compared with the untreated titanium alloy surface, both texture and TNTs structures would endow the titanium alloy surfaces with higher in vitro bioactivity. All three textures have an enhanced antibacterial property and a complete bactericidal effect was achieved by spray deposition of Ag nanoparticles (AgNPs) on all the surfaces. The MC3T3-E1 cells can adhere to the surfaces and proliferate normally, indicating good cytocompatibility of TiO 2 /Ag surfaces. Besides, the deposited AgNPs have been found to promote cell proliferation . • Tightly TiO 2 nanotubes have been prepared on surface-textured Ti6Al4V surfaces. • Ag Nanoparticles were spray-deposited onto micro/nano structures. • Both texture and TNTs structures would endow the titanium alloy surfaces with higher in vitro bioactivity and antibacterial property. • The deposited AgNPs have been found to promote cell proliferation.

Electron-hole plasma Fabry-Perot lasing in a Ga-incorporated ZnO microbelt via Ag nanoparticle deposition.

In this work, individual ZnO via Ga-doped (ZnO:Ga) microbelts with excellent crystallinity and smooth facets can enable the realization of lateral microresonator Fabry-Perot (F-P) microlasers, and the F-P lasing action originates from excitonic state. Interestingly, introducing Ag nanoparticles (AgNPs) deposited on the microbelt can increase F-P lasing characteristics containing a lower threshold and enhanced lasing output. Especially for the large size AgNPs (the diameter d is approximately 200 nm), the lasing features also exhibit a significant redshift of each lasing peak and an observable broadening of the spectral line width with an increase of the excitation fluence. And the remarkable lasing characteristics are belonging to the electron-hole plasma (EHP) luminescence. The behavior and dynamics of the stimulated radiation in an AgNPs@ZnO:Ga microbelt are studied, suggesting the Mott-transition from the excitonic state to EHP state that is responsible for the F-P lasing. These features can be attributed to the working mechanism that the hot electrons created by the large size AgNPs through nonradiative decay can fill the conduction band of nearby ZnO:Ga, leading to a downward shift of the conduction band edge. This novel filling influence can facilitate bandgap renormalization and result in EHP emission. The results provide a comprehensive understanding of the transition between excitonic and EHP states in the stimulated emission process. More importantly, it also can provide new scheme to developing high efficiency and ultra-low threshold microlasing diodes.

Constructing a novel AuAg/BiOBr/BaTiO3 composite via selective decoration route with enhanced visible-light photoatalytic performance

In this work, the BaTiO3 nanoparticles (hole acceptor) were firstly decorated on the surface of BiOBr nanoplates by hydrothermal method, and then AuAg alloy nanoparticles (electron acceptor) are selectively deposited on the uncovered surface of BiOBr nanoplates to form AuAg/BiOBr/BaTiO3 composite using visible-light photodeposition method. It is found that the BaTiO3 (∼55 nm) and AuAg (7–16 nm) nanoparticles are uniformly dispersed on the BiOBr surface, which are disconnected without direct contact between them. The visible-light photocatalytic degradation and reduction activity of products were evaluated using methyl orange (MO), acid orange 7 (AO7), rhodamine B (RhB) and Cr(VI) as the target reactant. After the combination of BiOBr with BaTiO3, the BiOBr/BaTiO3 composites exhibit enhanced photocatalytic activity. When the content of BaTiO3 reaches about 10%, the BiOBr/10%BaTiO3 composite exhibits best photocatalytic efficiency. Notably, the selective deposition of Au, Ag and AuAg alloy nanoparticles leads to the further enhancement of photocatalytic activity for BiOBr/10%BaTiO3 composite, and the optimal photocatalytic activity can be achieved over AuAg/BiOBr/10%BaTiO3 sample. The AuAg/BiOBr/10%BaTiO3 composite is demonstrated to be an stable photocatalyst, which also exhibits efficient synergistic photocatalytic activity for the purification of the RhB/Cr(VI) and AO7/Cr(VI) mixture. The photogenerated charges performance of products was measured by electrochemical work station. The main active species participated in the photocatalytic reaction of AuAg/BiOBr/10%BaTiO3 was detected. Based on above results, the synergistic modification mechanism of BaTiO3 and AuAg alloy nanoparticles on the photocatalytic activity of BiOBr was proposed.

Facile preparation of raspberry-like mesoporous poly(styrene-co-divinylbenzene)/Ag composite particles for antibacterial superhydrophobic surfaces and liquid marbles

Due to their unique properties, raspberry-like colloidal particles (RCPs) have been widely used in various fields. However, a facile, scalable and robust approach of producing raspberry-like colloidal particles remains an ongoing challenge. Herein, raspberry-like mesoporous poly(styrene-co-divinylbenzene) (PSD) polymeric particles were fabricated by one-step dispersion polymerization in the solvent mixture of ethanol and toluene. The morphologies of obtained polymeric particles could be easily tuned from spherical to raspberry-like structure by changing the composition of the solvent mixtures. A rational mechanism for the formation of raspberry-like polymeric particles was also proposed according to the morphological evolution under different copolymerization conditions. With the assitance of the immonilized PVP layer, the raspberry-like PSD colloidal particles can be further functionalized by depositing Ag nanoparticles on the particle surface. The antibacterial activity of raspberry-like PSD/Ag composite particles against E. coli was up to 99.99%. In addition, raspberry-like PSD/Ag composites can be further utilized to construct antibacterial superhydrophobic surface and liquid marbles.

Silver‐coated conductive composite fabric with flexible, anti‐flaming for electromagnetic interference shielding

AbstractWith the development of modern electronic technology, there is an urgent need to prepare multifunctional polymer composite materials with flame retardant and electromagnetic shielding functions. Herein, use the chemical activity of polydopamine (PDA) to modify polyphenylene (PP) fabric to enhance its interface compatibility. Then, the dipping method was used to achieve the successful deposition of Ag nanoparticles on the surface of the PP non‐woven fabric, and by adjusting the concentration of the Ag precursor and the immersion time of the flame retardant constructed a conductive composite material with lightweight, flexible and has good flame retardant properties. The results showed that when the concentration of AgNO3 solution was 2% and the thickness was 0.166 mm, the average shielding effectiveness shielding effectiveness (SE) and SSE/t of the composite fabric reached 25.01 dB and 6097.56 dB cm2g−1, respectively. In particular, the composite fabric still maintained stable electrical conductivity after flame retardant treatment, and the average shielding effectiveness SE and SSE/t of the composite fabric reached 20.20 dB and 1518.80 dB cm2 g−1. The multifunctional conductive composite fabric prepared in this study has broad development prospects in the fields of electromagnetic shielding and smart wear.

Monitoring and Optimisation of Ag Nanoparticle Spray-Coating on Textiles

An automatic lab-scaled spray-coating machine was used to deposit Ag nanoparticles (AgNPs) on textile to create antibacterial fabric. The spray process was monitored for the dual purpose of (1) optimizing the process by maximizing silver deposition and minimizing fluid waste, thereby reducing suspension consumption and (2) assessing AgNPs release. Monitoring measurements were carried out at two locations: inside and outside the spray chamber (far field). We calculated the deposition efficiency (E), finding it to be enhanced by increasing the spray pressure from 1 to 1.5 bar, but to be lowered when the number of operating sprays was increased, demonstrating the multiple spray system to be less efficient than a single spray. Far-field AgNPs emission showed a particle concentration increase of less than 10% as compared to the background level. This finding suggests that under our experimental conditions, our spray-coating process is not a critical source of worker exposure.

Enhanced uranium photoreduction on Ti3C2Tx MXene by modulation of surface functional groups and deposition of plasmonic metal nanoparticles

Photocatalytic reduction of soluble hexavalent uranium (U(VI)) is a novel and efficient avenue to enriching U(VI), where the free U(VI) is firstly bound on the surface of photocatalysts and then reduced to insoluble tetravalent uranium (U(IV)) by photoelectrons. Therefore, constructing the efficient U(VI) binding sites on photocatalysts is an efficient strategy to boost catalytic activity toward U(VI) photoreduction. Herein, we successfully constructed an efficient catalyst for U(VI) photoreduction by depositing Ag nanoparticles on Ti3C2Tx MXene with abundant U(VI) binding sites (Ag/Ti3C2Tx-O). Impressively, the U(VI) extracting mass over Ag/Ti3C2Tx-O under light reached up to 1257.6 mg/g in 120 min, which was almost 11 times as high as that without light. Further mechanistic studies indicated that the U(VI) binding sites on Ti3C2Tx MXene in Ag/Ti3C2Tx-O were beneficial to the reduction of U(VI) by significantly decreasing its reduction potential. More importantly, hot electrons generated by Ag nanoparticles were transferred into the binding sites to easily reduce the bound U(VI), resulting in the remarkable performance of Ag/Ti3C2Tx-O during U(VI) enrichment.

Deposition of Ag nanoparticles on polydopamine-functionalized CNTs for improving the tribological properties of PPESK composites

In this study, CNTs were first modified by polydopamine (PDA) to facilitate their surface activation and then Ag nanoparticles were in-situ grown on CNT-PDA to obtain CNT-PDA/Ag. The effects of functionalized CNTs on the tribological behaviors of poly (phthalazinone ether sulfone ketone) (PPESK) were investigated. Results revealed that PDA layer could not only increase the active functional groups on the CNT surface, but also act as an activated platform for the deposition of mono-dispersed Ag nanoparticles. The decoration of Ag nanoparticles decreased the interaction among CNTs, which was conducive to their good dispersion. Besides, by filling 0.3 wt% CNT-PDA/Ag, the thermal properties of PPESK were significantly improved, and its friction-reduction and anti-wear performances were the best among all PPESK composites, due to the good interfacial interaction between CNTs and PPESK, the synergistic reinforcing and lubricating effect of CNTs and Ag nanoparticles, as well as the lubricating effect of transfer film.

Ag nanoparticles immobilized on C:H:N:O plasma polymer film by elevated temperature for LSPR sensing

AbstractThe dependence of nanoparticles' plasmonic properties on the medium's material surrounding them finds utilization in sensing applications. However, as the detection sensitivity exponentially decreases with distance from the nanoparticles, direct contact between the medium and the nanoparticles is required to obtain the highest signal. This study shows how to prepare such a localized surface plasmon resonance sensor composed of gas‐phase synthesized Ag nanoparticles and magnetron sputtered C:H:N:O plasma polymer film. It is proved that excellent stability of Ag/C:H:N:O, enduring even ultrasound bath, may be reached by heating the C:H:N:O film during the deposition of Ag nanoparticles. Such a prepared sensor exhibits a sensitivity of 78 nm/RIU and detects medium changes at distances over 32 nm from its surface.

Acoustofluidic multimodal diagnostic system for Alzheimer's disease

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative brain disorder that affects tens of millions of older adults worldwide and has significant economic and societal impacts. Despite its prevalence and severity, early diagnosis of AD remains a considerable challenge. Here we report an integrated acoustofluidics-based diagnostic system (ADx), which combines triple functions of acoustics, microfluidics, and orthogonal biosensors for clinically accurate, sensitive, and rapid detection of AD biomarkers from human plasma. We design and fabricate a surface acoustic wave-based acoustofluidic separation device to isolate and purify AD biomarkers to increase the signal-to-noise ratio. Multimodal biosensors within the integrated ADx are fabricated by in-situ patterning of the ZnO nanorod array and deposition of Ag nanoparticles onto the ZnO nanorods for surface-enhanced Raman scattering (SERS) and electrochemical immunosensors. We obtain the label-free detections of SERS and electrochemical immunoassay of clinical plasma samples from AD patients and healthy controls with high sensitivity and specificity. We believe that this efficient integration provides promising solutions for the early diagnosis of AD.

Ag-doped Bi2WO6/BiOI heterojunction used as photocatalyst for the enhanced degradation of tetracycline under visible-light and biodegradability improvement

A new Bi2WO6/BiOI/Ag heterojunction composite was fabricated by the deposition of Ag nanoparticles on Bi2WO6/BiOI via two-step hydrothermal process and characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM) analyses. The photoelectric properties of the as-prepared composites were investigated by UV–vis diffuse reflectance spectrum (DRS), transient photocurrent response, electrochemical impedance spectroscopy (EIS) and photoluminescence spectrum (PLS). It was found that the amount of Ag in Bi2WO6/BiOI/Ag exhibited an evident influence on photoelectric properties and photocatalytic activity. Compared with the other as-prepared photocatalysts, Bi2WO6/BiOI/Ag-8 presented the highest photocatalytic activity for tetracycline degradation ascribed to the heterojunction structure and the surface plasmon resonance (SPR) action, which evidently enhanced the visible-light absorbance, and promoted the separation/transfer of photo-generated electron/hole (e–/h+) pairs. The organic intermediates formed during tetracycline photocatalytic degradation were identified and the degradation pathway was proposed. For the recommended photocatalyst, the hydroxyl radical (∙OH) and superoxide anion radical (∙O2–) produced by the Z-scheme photocatalytic mechanism with Ag as co-catalyst were responsible for the degradation. In addition, the photocatalytic degradation of tetracycline evidently reduced the solution toxicity and enhanced the biodegradability.

Enhanced photoluminescence of CdS quantum dots thin films on Cu and Ag nanoparticles

Fluorescent nanoparticles (NPs) exhibit unique optical properties which are utilized to prepare highly sensitive sensors. This paper illustrates the enhancement of luminescence emission of CdS quantum dots (QDs) from self-assembled metallic NPs of Cu and Ag. Metallic NPs, especially of Cu, Ag and Au exhibit unique and tunable plasmonic properties which are further manipulated by varying their size and shape. In the present study, plasmonic NPs were fabricated on glass substrate heated at 400 °C for the conversion of metallic layers into homogeneous NPs so as to create plasmonic response from these uniform NPs. The bimetallic layers of Ag and Cu NPs form a composite material having higher thermal conductivity, higher chemical stability and lower value of thermal expansion than monometallic layer of NPs. The photo-luminescence enhancement of CdS QDs thin films deposited on Cu and Ag NPs would find applications as light emitters and sensing devices. The attachment of CdS QDs on these bimetallic layers was confirmed by studying their optical properties. The morphology of the three prepared samples was analysed by scanning electron microscopy, which confirms the homogeneous deposition of spherical Cu and Ag NPs having size ranging from 20 to 55 nm (approximately). The above obtained outcomes illustrate the localized surface plasmon resonance characteristic of metal NPs which can be applied further for chemical and biological sensing

Effect of silver nanoparticles deposited on indium tin oxide by plasma-assisted hot-filament evaporation on phosphorescent organic light-emitting diode performance

This study investigates a high-density of silver (Ag) nanoparticles deposition in a two-dimensional array via a plasma-assisted hot-filament evaporation system on indium tin oxide (ITO) anodes for phosphorescent organic light-emitting diodes (PhOLEDs). The nanoparticles deposition process was conducted at substrate temperatures of 25, 80 and 140 °C. It is observed through atomic force microscopy that the deposited Ag nanoparticles size increases with higher substrate temperature. The surface plasmon resonances (SPRs) of the deposited Ag nanoparticles are influenced by particle size and interparticle spacing. The visible light transmittance of PhOLED was improved in the wavelength range from 500 to 600 nm at 25 and 80 °C conditions. The luminance efficiency of PhOLEDs with deposited Ag nanoparticles increased by 11.07, 5.03, and 70.30% with rising temperature compared to the standard PhOLED (no Ag nanoparticle) with colour stability. The enhancement in efficiency resulted from a coupling between the SPR of Ag nanoparticles and excitons in the emitting layer. The maximum efficiency was also due to a mirror-reflected emission effect via the larger Ag nanoparticles size. Moreover, the positive charges from the inner layer of the anode were enhanced by the high-density inserted Ag nanoparticles at 25 and 80 °C, increasing the hole carrier injection. The performance and mechanism of a PhOLED modified with Ag nanoparticles are discussed.

Solar irradiated selective nitroaromatics reduction over plasmonic Ag-TiO2: Deposition time dependent size growth and oxidation state of co-catalyst

Solar irradiated plasmonic Ag-TiO2 (P25) nanocomposites have proficiently harvested solar energy towards nitroaromatics reduction comparatively to almost irresponsive bare TiO2. p-Nitrotoulene (p-NT) and p-nitrobenzaldehyde (p-NBAL) were potentially reduced to p-aminotoulene (p-AT, 87% and 50%) and p-aminobenzaldehyde (p-ABAL, 70% and 38%) with Ag5-P25 (5 min photodeposition time (PDT)) and Ag30-P25 (30 min PDT) respectively. The focus of this study was mainly on the role of PDT (3–30 min) which was found to be directly co-related with size, distribution and oxidation state of deposited Ag nanoparticles (NPs) over titania surface, responsible for superior photocatalytic activity. HR-TEM images confirmed the average size of Ag nanoparticles to be ∼1–2 nm and ∼7–8 nm for Ag5-P25 and Ag30-P25 respectively. Further, XPS analysis suggested the formation of ternary hybrid (Ag2O/Ag-P25) in case of 5 min PDT whereas only metallic Ag was found to be photodeposited as the times was increased to 30 min.

Adjustable color response during plasmon resonance by monochromatic light irradiation.

A combination of plasmonic nanoparticles with a semiconductor is a feasible approach to realize multiple color exhibitions. The phenomenon is based on plasmon-driven charge separation between electrons and metal ions, but suitable only for light excitation with different wavelengths. Here, we introduce a color-adjustable method under monochromatic light irradiation. A smart strategy is proposed to construct sandwich structures of a hydrogel coating layer, thermally deposited Ag nanoparticles, and mesoporous TiO2 matrices. The contacting mode of TiO2 and nano-Ag at the Schottky interface is strongly dependent on the pore morphology of the oxide. Surface and interface plasmon resonances result in sample color switching from cyan to green and from brown to purple, respectively. The color response ability is further controlled by hydrogel coating, besides the exciting light wavelength. This Letter paves a bright way for colorful displays and information encryption.

Photo-reduced WO3/PAN nanofiber membranes with deposited Ag nanoparticles as efficient SERS substrates

Sensitive SERS substrates specified for sensing is highly desired owing to their increasing demand for environment monitoring, disease diagnosis, and chemical analysis. Here, we fabricate amorphous WO3/polyacrylonitrile (WO3/PAN) nanofiber membranes through electrospinning. The photo-reduced NFM show a free carrier concentration up to 1.46 × 1021 cm−3, which is 5 times increased compared with the oxidized NFM and approaching that of the noble metals (2.5 × 1022 cm−3). The detection limit concentration was as low as 10-9 M and SERS enhancement factor can be obtained 0.6 × 105 for the photo-reduced NFM. With in-situ Ag deposition on the surface of the NFM, the SERS enhancement factor can be further increased to 2.9 × 105. More interestingly, since the open structure and high utility of the pores of nanofiber membranes and allow rapid airflow through the membranes, the modified Ag deposited NFMs can be used as SERS substrates for gas sensing with rapid response time (tens of seconds) and low detection limit (10 ppb). Such a simple, low-cost fabrication method to prepare SERS substrate for detecting pollutants in water and gas sensing is promising for future applications.