Ag Decoration Research Articles

Synergetic engineering of oxidizable, redox, and inert metal decorated copper oxide for non-volatile memory and neuromorphic computing applications

Abstract In the quest for efficient resistive switching (RS) materials for both non-volatile memory and neuromorphic computing applications, a variety of functional materials have been researched in the last few years. Herein, we systematically synthesized Ni, Ag, and Au decorated copper oxide (CuxO) by using an electrochemical approach and investigated their RS performance for both non-volatile memory storage and neuromorphic computing applications. By tuning various electrochemical parameters, we optimized Ni, Ag, and Au decoration over the CuxO switching layers to understand the effect of oxidizable, redox, and inert metal decoration, respectively. Fabricated Ni-CuxO/FTO, Ag-CuxO/FTO, and Au-CuxO/FTO devices show forming-free bipolar and analog properties of RS behavior. The electrical measurements asserted that the electrodeposited Ni-CuxO/FTO RS device shows excellent RS, non-volatile memory, and synaptic learning properties compared to the Ag-CuxO/FTO, and Au-CuxO/FTO devices. Moreover, the statistical and Weibull distribution parameters suggested that the Ni-CuxO/FTO RS device has lower switching variation than the other two devices. The conduction mechanisms of all devices are investigated by fitting the appropriate physics-oriented models. It was found that Ohmic and Child's square law were dominated during the charge transport and the RS process occurred due to the filamentary switching effect. Results suggested the electro-decorated/-deposited Ni-CuxO is a suitable switching layer for memory as well as neuromorphic computing applications.

Highly efficient SnO2-Carbon nanosphere heterojunctions decorated with Ag for detecting isopropanol at low operating temperatures

The design of a sensing material for detecting isopropanol gas with low operating temperature is extremely important for miniaturization and wearability of gas sensors. Herein, a novel gas sensor based on SnO2-Carbon nanosphere heterojunctions decorated with Ag nanoparticles (SCA) was fabricated and its gas sensing performance was evaluated and compared systematically. The measurement results indicated that the sensing performance was influenced by the ratio of Sn/C and the length of Ag plating, and the SCA sensor provided the best response. For 100 ppm isopropanol at 100 °C, the SCA sensor exhibited a response value of 50.51, a response time of 7 s and a recovery time of 60 s. The enhanced sensing performance and reduced operating temperature of the SCA could be attributed to the synergistic effect of the SnO2-Carbon nanosphere heterojunctions and the significant catalytic performance of the decorated Ag nanoparticles. In addition, the density functional theory calculation method based on the first-principles theory was used to study the adsorption performance and electronic behavior, as well asthe influence of Ag decoration on SnO2 for isopropanol detection. The calculated results were consistent with the experimental results.

A strategy to reutilize silver nanoparticles on silicon nanowires via photocathodic activation for enhanced and sustainable hydrogen evolution

The development of electrodes for hydrogen evolution via water splitting in a neutral electrolyte is highly desirable, especially considering that natural water resources such as seawater typically have a neutral pH. In this study, silicon nanowires (SiNWs) arrays with uniform silver (Ag) decoration are prepared as a cathode material, which exhibits excellent and stable electrochemical performance for neutral water electrolysis. Ag ions, utilized in the preparation of SiNWs through metal-assisted chemical etching technique, are retained and decorated within the SiNWs array without undergoing a dissolution process, referred to as Native SiNWs. Remained Ag+ ions on the SiNWs are activated photocathodically and reduced to Ag0, resulting in a significantly enhanced performance as an electrocatalyst for hydrogen evolution reaction (HER). Hence, this photocathodic activation of Native SiNWs (PCA-Native SiNWs) eliminates the need for additional cocatalyst deposition for HER, utilizing the Ag ions employed in the SiNWs preparation process. This enhancement in HER activity is exclusively observed by photocathodic activation, not by cathodic activation without light irradiation, indicating the crucial role of photoelectrons in SiNWs under light irradiation for the activation. Additionally, the nanowire structure serves as an ideal platform for Ag nanoparticles, providing sufficient surface area, resulting in excellent dispersion and an increased number of active sites. Furthermore, PCA-Native SiNWs demonstrates outstanding electrochemical stability for over 60 h, with no significant reduction in current density or structural degradation in a neutral electrolyte. Several characterizations and electrochemical analyses have been conducted to elucidate the in-situ decoration of Ag nanoparticles on SiNWs and investigate the surface chemistry for the activation mechanism. This work introduces a new perspective on using Ag-decorated SiNWs directly as an electrocatalyst for effective hydrogen evolution in a neutral media.

Ag decoration as a strategy to enhance the methanol and ethanol sensing on the biphenylene sheet

Efficient, miniaturized, and highly sensitive sensors to detect volatile organic compounds (VOCs) have become vital tools to minimize pulmonary diseases and other sicknesses. Therefore, the adsorption capabilities of methanol and ethanol were investigated on the recently synthesized biphenylene (BPN) monolayer using the Ag decoration. Although the pristine BPN has suitable VOCs adsorption, the lower adsorption strength and the small charge transfer affect the sensor performance. On the other hand, the Ag decoration increases the gas sensitivity, with moderate chemisorption values of –0.67eV and –0.83eV for methanol and ethanol, respectively, and transitory chemical bond character (neither ionic nor covalent) between Ag atoms and the –OH radical. In addition, significative work function changes (Δϕ > 0.23 eV), huge charge transfer, and rapid recovery times at room temperature, τ = 0.18s and τ = 87.9s for methanol and ethanol, respectively, indicate a great VOCs sensitivity. The feasibility of the Ag-BPN and Ag-BPN + VOCs systems by ab initio molecular dynamics (AIMDs) was analyzed, which confirms that both systems are stable at 500K. Therefore, the DFT calculations employed here can guide experimentalists in exploring new miniaturized sensor devices based on BPN.

Synthesis, characterization, and FDTD simulations of Ag-enriched RGO nanosheets for catalytic reduction of 4-nitrophenol

Reduced graphene oxide-based nanocomposites are eminent materials having diverse applications including environmental remediation. The present work emphasizes the facile one-step co-reduction method for synthesizing silver nanoparticle (Ag NPs) decorated reduced graphene oxide (RGO) for catalytic reduction of 4-nitrophenol. FDTD simulation studies justify the experimental results, and XRD studies confirmed the reduction of graphene oxide and the formation of Ag NPs with reduced graphene oxide (AgRGO) composite. Raman analysis complements the structure, crystallinity, and defects in the fabricated material. XPS analysis verifies the reduction of graphene oxide (GO) into RGO and the decoration of metallic Ag on the surface of RGO. FESEM image showed the decoration of Ag NPs on the surface of RGO. AgRGO exhibited appreciable catalytic performance for reducing 4-nitrophenol in the presence of sodium borohydride compared to GO and RGO.

Investigation of Ag nanoparticles decorated Ni-Al layered double hydroxide as a gas sensor

Chemiresistive gas sensors based on LDH structure were investigated for the detection of widely used volatile organic compounds (VOCs) including methanol, ethanol, and acetone at room temperature. In order to increase the surface active sites and subsequently improve the detection sensitivity of gas molecules, the use of Ag decoration method along with the creation of porosity on the surface of LDH structures were investigated. In this method, methanol solvent was used as a hole scavenger and UV radiation as a catalyst for binding Ag to the surface of LDH sheets. The microstructure and morphology of the composites were investigated by FESEM, HRTEM, EDS, EDS mapping, XRD, and MS analysis. The investigated parameters included relative humidity, calibration curve, repeatability, selectivity, and response/recovery times. According to the obtained results, the creations of surface corrosion by methanol and decorating the structure with Ag have both affected the sensitivity of the sensors. The pure Ni-Al LDH sensor has a response value of 6.8–250 ppm of ethanol. By increasing the specific surface area and creating LDH nanosheets, the response value can be increased up to 8.52. Also, the addition of Ag NP (Ni-Al LDH decorated with Ag NP) has increased the response up to 10.89. It was also observed that the response times in different modes have the least difference. At the end, the response mechanism was investigated based on the heterojunction theory.

Surface addition of Ag on PbO2 to enable efficient oxygen evolution reaction in pH-neutral media

Electrocatalysts, particularly earth-abundant metal oxide ones, exhibit poor performance in catalyzing the oxygen evolution reaction (OER) under neutral conditions due to low ionic concentrations. This study introduces a novel strategy for fabricating a PbO2 + Ag composite electrode with significantly improved OER activity and stability in a pH-neutral environment. Our results suggest that incorporating Ag as a surface additive improves the efficiency of utilizing adsorbed oxygenated species via the bridge-site-top-site pathway. Moreover, the surface decoration of Ag resulted in enhanced electrocatalytic stability by diverting the attack of oxygenated species to Pb thereby effectively preventing Pb dissolution. The results not only establish a method for utilizing PbO2 in pH-neutral OER applications, but also propose a potential strategy for employing less noble catalysts in cost-effective electrochemical energy conversions.

Novel MgO and Ag/MgO nanoparticles green-synthesis for antibacterial and photocatalytic applications: A kinetics-mechanism & recyclability

The present study identifies the novel nano production of MgO nanoparticles as well as the Ag decoration of MgO nanoparticles using Morinda tinctoria plant extract. Green compounds are used to reduce zero valent atoms and to decorate metal oxide surfaces. X-ray Diffractometer analysis (XRD) was used to examine the cubic structure of MgO (28 nm) and Ag/MgO (21 nm) nanoparticles. Fourier transform infrared spectroscopy (FTIR) analysis was used to determine the reactive functional groups, metal–oxygen bonding, and OH molecules. Ultra-Violet Diffuse Reflectance Spectroscopy (UV-DRS) analysis revealed the optical entity and their orbital electron shift. Using the Kubelka-Munk relation, the optical defect of MgO (4.68 eV) and Ag/MgO (3.18 eV) nanoparticles was calculated. Scanning Electron Microscope (SEM) indicated surface decorations and their pure MgO nanoparticles rod-like shape, and Energy-Dispersive X-Ray Spectroscopy (EDX) identified their elements. TEM analysis confirmed the poly-dispersive nature of the Ag decorations on the MgO surface. X-Ray Photoelectron Spectroscopy (XPS) was used to determine the valency of metal (Ag-3d) and metal oxide (Mg-2 s&O-1 s). MgO and Ag/MgO were used in visible light photocatalytic dye degradation of Rh-B dye. The biological properties were tested against S.aureus and E.coli. The plasmonic decoration on the MgO surface accelerated photodegradation and increased biological susceptibility. The innovative characteristics of this work squeeze the green synthesis of Ag/MgO nanoparticles, their improved photocatalytic and antibacterial performance, and their potential applications in water remediation and biomedicine.

Green synthesis of Ag and Au NPs decorated rGO nanocomposite for high impedimetric electrochemical sensor as well as enhanced antimicrobial performance against foodborne pathogens

In the present study, Allium cepa L. leaves extract mediated silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) decorated reduced graphene oxide (Ag/Au/rGO NC’s) were synthesized and demonstrated their biological and electrochemical sensing applications. Interestingly, the synthesis of AgNPs and AuNPs was achieved rapidly within 1 h and 4 h, respectively. Whereas the production of both reduced graphene oxide (rGO) and Ag/Au/rGO NC’s was achieved at 96 h. The achieved results from the UV–Vis spectrum of 432 nm for AgNPs and 550 nm of AuNPs and the shifting of the characteristic GO absorption band of 230 nm into 270 nm as well as an absence of 305 nm confirmed the rGO synthesis. In addition, HR-XRD analyses confirmed the JCPDS file No. 04–0783 and 01–1174 pertaining to Ag and Au NPs. Further, the Raman spectroscopy, FT-IR and EDS analyses confirmed the evidence of nanomaterials biosynthesis. A polydisperse, spherical shaped average size AgNPs of 1 to 30 nm, spherical and triangular shaped AuNPs with an average size of 1 to 120 nm, and silk like appearance of a thin layered graphene sheet in rGO were observed through TEM. Also, the recorded results evident the uniform decoration of Ag and Au NPs into the rGO sheet. The electrochemical properties of as-synthesized materials were studied by electrochemical impedance spectroscopic (EIS) and cyclic voltammetry (CV) techniques. Interestingly, the Ag/Au/rGO NC’s modified electrode exhibited higher electrical conductivity and good electrocatalytic properties towards the electrooxidation of nitrite in a neutral medium than other nanomaterials. Eventually, Ag/Au/rGO NC’s confirmed the enhanced antibacterial against Gram-negative bacteria and dose dependent antifungal inhibitory activities against foodborne fungal pathogens of Fusarium graminearum, Alternaria alternata, and phytopathogenic fungus of Curvularia lunata and Sclerotinia sclerotiorum at the maximum tested conc. of 2 mg/mL, compared to other nanomaterials. From the result of zebrafish embryotoxicity (ZET), the highest toxicity was observed for AgNPs at 0.19 μg/mL. But in the case of Ag/Au/rGO NC’s the reduced toxicity was observed. Hence, the achieved results concluded the Ag/Au/rGO NC’s could be suitable for development of both as biomaterials for biomedical and effective sensors for environmental applications.

Catecholate Dye-Assisted Decoration of Ag on TiO2 Nanoparticles for Detection of Cancer-Related MicroRNA Biomarkers on a Multiplexed Photoelectrochemical Platform

Catecholate Dye-Assisted Decoration of Ag on TiO₂ Nanoparticles for Detection of Cancer-Related MicroRNA Biomarkers on a Multiplexed Photoelectrochemical Platform

Ag decorated CuGaO2 nanosheets for enhanced ethylene glycol detection

Metal oxide semiconductors stand at an essential frontier of chemiresistive substance for gas sensor assembly to detect the volatile organic compounds, especially in case of the trace amount related to human health. In this work, we present a new gas sensor based on hydrothermally synthesized CuGaO2 nanosheets with Ag decoration, which performs an enhanced selectivity, sensitivity, and response/recovery speed towards ethylene glycol. Based on the structural characterization and systematic gas detection results, the gas sensing mechanism is elucidated by the first principles calculations and energy band theoretic analysis, in which the extraordinary gaseous adsorption and charge transfer onto the solid surface is responsible for the high susceptibility of Ag decorated CuGaO2 to ethylene glycol. Meanwhile, Ag hybridization is further confirmed to provide the additional approach to boost the efficiency of electron transfer. It is an innovative perspective to study the chemiresistive gas sensing by comparing the preference of charge transfer from the adsorbed organic gas molecule towards the hybridized solid surface, which presents a new route to design the material system of advanced sensing devices for the specific applications.

Schottky-junction plasmonic nanocomposite: A non-hazardous excellent visible light photocatalyst for industrial waste management

A bio-compatible nanocomposite “Ag/Ag doped TiO2” with UV–Visible-NIR light gathering quality was synthesized by solvothermal method, followed by green synthesis method. Insertion of Ag+ ions into Ti2+ lattice sites in Ag doped TiO2 alters the n-type TiO2 semiconductor to p-type. Nanostructured doped TiO2 suffers high charge recombination loss in presence of trapped states, resulting 35 % photocatalytic efficiency. Ag decoration on p-type Ag doped TiO2 forms a Schottky barrier at metal-semiconductor junction, which reduces charge recombination loss by separating the photogenerated electron-hole (e-h) in two materials of the nanocomposite. These photogenerated charges create oxide and hydroxide super radicals in the aqueous system of photocatalyst, ensuing 80% degradation of SO dye under 50 min white light illumination. The nanocomposite also demonstrated good performance in degradation of industrial dyes like 50% Mordant Orange (MO) and 15% Direct Blue (DB) under 50 min white light irradiation. DFT analysis of the heterosystems supports absorptivity tuning of experimentally obtained nanocomposite. Moreover, the nanocomposite proved its non-toxicity to human cells, as it reveals <20% cell death with maximum dose (250 µg/ml) of the nanocomposite in cytotoxicity test. Hence, proper designing and synthesizing the nanocomposite explored an eco-friendly solar photocatalyst for industrial waste management.

Ag decorated-Cu2O catalysts with enhanced selectivity for CO2 electroreduction toward C2+ products

Copper-based electrocatalysts have been widely used to generate C2+ products via the electrocatalytic carbon dioxide reduction reaction (CO2RR) because the catalysts possess unique properties for C-C coupling. Tandem catalysis is an attractive concept for C2+ production, enhancing selectivity and activity by combining CO-generating catalysts with Cu-based catalysts. Herein, the ability of Ag decoration to improve the selectivity of the Cu2O catalysts for C2+ production was investigated. The Ag/Cu2O catalyst with 10 wt% Ag content on the Cu2O surface (10 Ag/Cu2O) exhibited high Faradaic efficiency (FE) of 48% for C2+ products at –0.99 V (vs. RHE). Moreover, the partial current density of C2+ products on the 10 Ag/Cu2O was improved by 33% compared to the bare Cu2O catalyst. The intermediate (CO) generated on the Ag surface migrates by diffusion and/or sequential desorption-re-adsorption from Ag to Cu at the Ag-Cu interface of the Ag/Cu2O, increasing CO coverage on the Cu surface. The increase in CO coverage on the Cu surface of the Ag/Cu2O catalysts after decoration with Ag effectively reduces the hydrogen evolution reaction (HER), enhancing C-C coupling to generate C2+ products on the Ag/Cu2O. In addition, density functional theory (DFT) calculation results also revealed that Ag provides more CO2 activation sites, increasing CO coverage and reducing hydrogen adsorption energy, thus suppressing HER and improving the selectivity of CO2RR toward C2+ production.

Design and performance analysis of a PV-assisted alkaline electrolysis for hydrogen production: An experimental and theoretical study

The PV assisted alkaline electrolysis cell was established for hydrogen generation. Lab-made AgNiCu modified nickel foam cathodes were used in this system. The characterization was achieved using field emission scanning electron microscopy, energy-dispersive X-ray and X-Ray diffraction analysis. The electrochemical performance was investigated via linear sweep voltammetry, cyclic voltammetry, Tafel polarization measurements and electrochemical impedance spectroscopy. The electrolysis potential and time depended efficiency was monitored. The structural theoretical analysis of the electrode surface and hydrogen evolution characteristics were also determined applying Density Functional Theory and Ab-initio Molecular Dynamics simulations which identified the role of Ag decoration and Cu incorporation on the surface against water and proton adsorptions. The modified cathode (AgNiCuF) improved the hydrogen production performance owing to lower hydrogen onset potential (−1.1 V) and charge transfer resistance (0.362 ohm at −1.5 V).

Enhancing water resistance of α-MnO2 catalyst for efficient airborne benzene oxidation at mild temperatures via facile Ag incorporation

Facile structural modification of α-MnO2via single incorporation of Ag element was applied to achieve high-efficiency oxidation removal of benzene, particularly under wet gas. Ag+ ions could enter the MnO2 structure by partially replacing the tunnel K+ ions, leading to lower crystallinity, smaller crystallite and distorted lattice arrangement. Due to electron transfer from Ag+ to lattice oxygen, Ag decoration weakened Mn-O bonds and the bulk lattice oxygen became more mobile to migrate towards the Ag-MnO2 surface, resulting in the larger number of surface lattice oxygen. Along with the abundance of oxygen species, the reactivity of surface adsorbed oxygen and lattice oxygen was significantly improved as well by Ag modification. All these factors were favorable to the complete C6H6-to-CO2 conversion. Gaseous benzene could be directly oxidized by oxygen species over the pristine MnO2 catalyst, while the adsorptive activation of gaseous benzene was required for the Ag-MnO2 before further oxidation. As to the Ag-MnO2’s endurability of moisture-aroused inactivation, Ag species oppressed water adsorption in the form of strong adsorbate, thus preventing structural damage of the catalyst during humid benzene oxidation. Moreover, water molecules could enhance the “Ag-MnO2vs. adsorbed benzene” interaction, which increased the oxidation efficiency of adsorbed benzene. However, the strong binding of water vapor with the MnO2 surface would cause strong restriction of gaseous benzene from approaching the surface oxygen species, resulting in much less benzene being oxidized under wet gas.

Formulating the Li sites of Li-CoOx composites for achieving high-efficiency oxidation removal of formaldehyde over the Ag/Li-CoOx catalyst under ambient conditions

Oxide supported noble metals are extensively investigated for ambient formaldehyde oxidation, and the Ag-CoOx complex is one promising combination in terms of cost and activity. Further, we previously observed that cooperating Ag with Li + greatly boosted formaldehyde degradation on CoOx. Yet, there is still room for improvement in removal efficiency, mineralization capacity and resistance to severe conditions. These objectives could be realized via strategically formulating the Li+ sites of Li-CoOx composite in this sister study. Three samples with Li + ---Co3+—O2- connections (L-CO), spinel Li+ (LCO-S) and layered Li+ (LCO-L) were obtained at low (300 °C), moderate (500 °C) and high (700 °C) temperatures, respectively. The specific Li+ positions and componential interaction were demonstrated by Hyperspectral imaging (HSI), XRD, SEM, TEM, HAADF mapping, UV–vis DRS and XPS. Moreover, the effect of reactive oxygen exposure on catalytic oxidation of formaldehyde (330–350 mg/m3) was disclosed through CO-TPR and O2-TPD. Compared with the LCO-S and LCO-L, L-CO exhibited dominant formaldehyde degradation due to the larger content of surface oxygen. After Ag decoration, the Li+---Co3+—O2- connections uniquely caused a strong binding of Ag species with catalyst host, which boosted the amount of reactive oxygen and finally resulted in an even higher elimination of ∼73% (CO2 yield = ∼21%), 47% higher than that of the L-CO (CO2 yield = ∼6%). But in contrast, the Ag@LCO-S only achieved ∼53% removal (CO2 yield = ∼9%) and Ag modification was powerless in altering the inertness of LCO-L, demonstrating that the chemical environment of alkali metal is crucial to effectively tuning the catalyst activity. The advantage of Ag@L-CO in formaldehyde depollution was further reflected from its much better resistance to moisture and aromatic compound omnipresent in indoor air. For the first time, this study extended the understanding of the alkali-metal-promoted formaldehyde oxidation reaction to an in-depth level.

Atmosphere-Dependent Electron Relaxation of the Ag-Decorated TiO2 and the Relations with Photocatalytic Properties

In the current research, the atmosphere effects on the photoinduced electron relaxations of the undecorated TiO2 and Ag-decorated TiO2 (Ag/TiO2) were carefully studied by means of the in situ photoconductance and diffuse reflection measurements. In pure N2 atmosphere, the results showed that the electron relaxation mainly occurs through the transfer to the residual O2, and the Ag nanoparticles form a fast electron transfer pathway. It was seen that the apparent activation energy of the electron transfer to O2 was greatly reduced by the Ag decoration. In the methanol-containing N2 atmosphere, the electron relaxation can still occur via the transfer to residual O2 in the case of the undecorated TiO2, while the relaxation mechanism changes for the Ag/TiO2 as the relaxations are decreased with the temperatures. It is possible that the methanol molecule adsorbed on the Ag/TiO2 perimeters could act as the bridge for the recombination of the holes and the electrons stored in the Ag nanoparticles. Reducing the Ag nanoparticle size from 15 nm to 3 nm can greatly increase the electron relaxations due to the increase in Ag dispersion and Ag/TiO2 interconnection. Although the electron transfer to O2 was increased, both the photocatalytic oxidations of acetone and isopropanol showed a decrease after the Ag decoration. The results indicated that the photocatalytic oxidation was not limited by the electron transfer to O2. The increased electron transfer to O2 contributed to the recombination around the Ag/TiO2 perimeters, and the photocatalytic activities were decreased.

Promotional effects of Ag decoration on root-like ZnO microstructures for ethanol sensing

Promotional effects of Ag decoration on root-like ZnO microstructures for ethanol sensing

Surface modification of organic hybrid indium sulfide via silver ion decoration with enhanced photocatalytic activity for degrading organic dyes and antibiotics

Crystalline organic hybrid metal chalcogenides have exhibited effective photocatalytic degradation ability for organic pollutants. However, few strategies have been applied to enhance its inherent photocatalytic degradation activity. Here, we used an organic hybrid indium sulfide [In8S13(S)1/2(SH)][In4S6(S3)1/2(SH)](TMDPH2)5 (HCF-1) (TMDP = 4,4′-trimethylenedipiperidine) as pristine material, by immersing HCF-1 into AgNO3 solution, the surface of HCF-1 crystal was decorated by Ag+ ions via electrostatic interaction. Compared with the pristine HCF-1, the as-modified Ag@HCF-1 exhibited enhanced photocatalytic degradation performance for organic dyes (RhB and MO) and antibiotics (TC and ENR). The decoration of Ag+ ions on the surface of HCF-1 can broaden the range of light absorption, and promote the separation of photo-generated carriers, and thus boost the photocatalytic activity. In addition, photocatalytic mechanism was studied by free radical capture experiments, which proved the dominant roles of h+ and •O2− in the degradation process.

Hydrothermally synthesized Ag decorated β-Ga2O3 heterostructures as low cost, reusable SERS substrates for the nanomolar detection of rhodamine 6G

Metal oxide semiconductors and plasmonic metal nanoparticles have received extensive research interest due to their superior optical properties resulting from the combination of semiconductor and plasmonic properties. Herein, we demonstrate the synthesis of Ag decorated β-Ga2O3 heterostructures utilizing a cost effective and eco-friendly hydrothermal method. The decoration of Ag endows plasmonic features to the hybrid material resulting in broad absorption in the visible light region of the electromagnetic spectrum, which is not possible for bare β-Ga2O3 due to its wide bandgap. The peculiar nature of the hybrid material was then utilized to fabricate an efficient substrate for surface enhanced Raman scattering (SERS) applications. The recyclability and prolonged stability of the substrate indicate its potential application toward the fabrication of versatile and low-cost SERS substrates.