Defect state enhanced nonlinear absorption and optical limiting behaviour of erbium doped silver molybdate nanostructures

Transition metal based optical limiting materials have garnered significant attention due their crucial role in protecting sensitive optical system from high intense laser damage. Transition metal molybdates exhibits nonlinear optical (NLO) response, which attenuate highly intense light by transmitting light of desired intensity. Herein we report Silver molybdate (Ag2MoO4) nanostructures doped with erbium (Er) ions were successfully synthesized by simple co-precipitation technique. The proper incorporation of Er ions into the Ag2MoO4 lattice without altering the crystal structure was confirmed by XRD Analysis. The optical properties studied using UV-Vis absorption Spectroscopy exhibited maximum absorption in UV region and the absorption in the visible region is found to increase with the addition of Er ions into the host lattice. The XPS spectra confirmed the + 3 oxidation state of erbium and Ag0 state of silver. The NLO parameters such as, nonlinear absorption (NLA) and optical limiting (OL) was studied for the first time under 532 nm nanosecond laser excitation. Results suggest that erbium doped silver molybdate exhibited reverse saturable absorption originated from two photon absorption. The synthesized samples exhibited excellent nonlinear absorption and optical limiting performance. Also it is observed that with the addition of Er ions, the two photon absorption (2PA) is found to enhance from 0.85 × 10-10 m/W (pure Ag2MoO4) to 6.223 × 10-10 m/W for 0.5% Er doped sample. So, erbium doped silver molybdate nanostructures can be used for various tunable optoelectronic devices.

Silver molybdate: an excellent optical limiting material under nanoregime for photonic device application

There is a mounting demand for nonlinear optical materials with superior optical limiting performance which has a noticeable impact on protecting the delicate optical components from laser-induced damage. Transition metal molybdates have garnered attention in the nonlinear optics field due to their outstanding optical and luminescent properties, which give rise to widespread applications in next-generation optoelectronics devices. The structural confirmation of the as prepared silver molybdate nanoparticles were made by XRD and Raman spectroscopy analysis. The linear optical properties and the band gap of the synthesized material were studied using UV-Visible and photoluminescence spectroscopy. SEM analysis revealed the pebble like morphology of the silver molybdate nanostructures. The nonlinear responses of the samples were studied using open aperture z-scan approach with Nd:YAG pulsed laser (532 nm, 9 ns, 10 Hz). The sample exhibits reverse saturable absorption pattern attributed to the two photon absorption (2PA) mechanism. The obtained OL threshold value is in the order of 1012 which is suitable for fabricating optical limiters in nano second pulsed laser regime.

Plastic optical fibres applied on the photocatalytic degradation of phenol with Ag2MoO4 and ß-Ag2MoO4/Ag3PO4 under visible light

In this study, plastic optical fibre (POF) was considered as a light-transmitting medium and substrate for use in a photocatalytic environmental purification system, using Ag₂MoO₄ and β-Ag₂MoO₄/Ag₃PO₄ as photocatalysts. Pure Ag₂MoO₄ and a β-Ag₂MoO₄/Ag₃PO₄ composite were synthesized using a facile precipitation method. The composition, structures and optical properties of as-prepared catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), field-emission scanning electron microscopy (FESEM), UV/Vis diffuse reflectance spectroscopy (UV/Vis DRS), BET surface area and TGA/DTG. The catalysts were immobilized on POF and on the glass reactor surface and their efficiency in the phenol degradation was evaluated in a batch reactor under visible light. The use of POF offers advantages such as ease of handling and good adherence characteristics to support Ag₂MoO_4. The photoactivity follows the order β-Ag₂MoO₄/Ag₃PO₄ ≅ Ag₂MoO₄> TiO₂ P25, for photocatalysts immobilized on the glass reactor surface or in aqueous suspension. The immobilization of Ag₂MoO₄ on POF revealed that thinner Ag₂MoO₄ coatings achieved faster pollutant removal rates from solution, and the optimal catalyst deposition is 0.64 mg/cm², causing maximum the light penetration and electron-hole generation close to the solid-liquid interface.

Synthesis and enhanced photocatalytic activity of the flower-like CdS/Zn3(PO4)2 Z-scheme heteronanostructures

CdS/Zn3(PO4)2 Z-scheme heteronanostructures were prepared through a simple hydrothermal route and precipitation methods, and the efficiency for the photocatalytic degradation of MB solution can be improved greatly.

Silver molybdate nanoparticles based immunosensor for the non-invasive detection of Interleukin-8 biomarker

In this study, we report the silver molybdate nanoparticles (β-Ag₂MoO₄ NPs) based non-invasive and sensitive electrochemical immunosensor for label-free detection of Interleukin-8 (IL-8) biomarker. The X-ray diffraction and Raman spectroscopy studies confirm the cubic spinel structures of β-Ag₂MoO₄ NPs. High-resolution transmission electron microscopy study depicted average size of β-Ag₂MoO₄ NPs as 27.15 nm. The cleaned indium tin oxide coated glass substrates were coated with spin-coated thin films of Ag₂MoO₄ NPs. These electrodes used for covalently immobilization of antibodies specific to IL-8 (Anti-IL-8) using EDC-NHS chemistry and unbound activated sites blocked by bovine serum albumin. Electrochemical response was obtained in the range of 1 fg mL^-1 to 40 ng mL^-1 and the sensitivity was found to be 7.03 μA ng^-1mL cm^-2 with LOD of 90 pg mL^-1. Spiked samples prepared by human saliva were tested and found efficient detection with this immunoelectrode.

Unvealing the role of β-Ag2MoO4 microcrystals to the improvement of antibacterial activity

Crystal morphology with different surfaces is important for improving the antibacterial activity of materials. In this experimental and theoretical study, the antibacterial activity of β-Ag₂MoO₄ microcrystals against the Gram-positive bacteria, namely, methicillin-resistant Staphylococcus aureus (MRSA), and the Gram-negative bacteria, namely, Escherichia coli (E. coli), was investigated. In this study, β-Ag₂MoO₄ crystals with different morphologies were synthetized by a simple co-precipitation method using three different solvents. The antimicrobial efficacy of the obtained microcrystals against both bacteria increased according to the solvent used in the following order: water < ammonia < ethanol. Supported by experimental evidence, a correlation between morphology, surface energy, and antibacterial performance was established. By using the theoretical Wulff construction, which was obtained by means of density functional calculations, the morphologies with large exposition of the (001) surface exhibited superior antibacterial activity. This study provides a low cost route for synthesizing β-Ag₂MoO₄ crystals and a guideline for enhancing the biological effect of biocides on pathogenic bacteria by the morphological modulation.

Facile synthesis of new polyhedron-like WO3/butterfly-like Ag2MoO4 p–n junction photocatalysts with higher photocatalytic activity in UV/solar region light

A series of novel efficient polyhedron-like WO₃/butterfly-like Ag₂MoO₄ p–n junction photocatalysts (denoted as AMW-x) were designed and synthesized.

Selective oxidation of alcohols by using CoFe2O4/Ag2MoO4 as a visible-light-driven heterogeneous photocatalyst

Using a CoFe₂O₄/Ag₂MoO₄ heterostructure as a novel, stable, inexpensive, and reusable photocatalyst with high-performance for the oxidation of alcohols.

Fabrication of potato-like silver molybdate microstructures for photocatalytic degradation of chronic toxicity ciprofloxacin and highly selective electrochemical detection of H2O2

In the present work, potato-like silver molybdate (Ag₂MoO₄) microstructures were synthesized through a simple hydrothermal method. The microstructures of Ag₂MoO₄ were characterized by various analytical and spectroscopic techniques such as XRD, FTIR, Raman, SEM, EDX and XPS. Interestingly, the as-prepared Ag₂MoO₄ showed excellent photocatalytic and electrocatalytic activity for the degradation of ciprofloxacin (CIP) and electrochemical detection of hydrogen peroxide (H₂O₂), respectively. The ultraviolet-visible (UV-Vis) spectroscopy results revealed that the potato-like Ag₂MoO₄ microstructures could offer a high photocatalytic activity towards the degradation of CIP under UV-light illumination, leads to rapid degradation within 40 min with a degradation rate of above 98%. In addition, the cyclic voltammetry (CV) and amperometry studies were realized that the electrochemical performance of Ag₂MoO₄ modified electrode toward H₂O₂ detection. Our H₂O₂ sensor shows a wide linear range and lower detection limit of 0.04-240 μM and 0.03 μM, respectively. The Ag₂MoO₄ modified electrode exhibits a high selectivity towards the detection of H₂O₂ in the presence of different biological interferences. These results suggested that the development of potato-like Ag₂MoO₄ microstructure could be an efficient photocatalyst as well as electrocatalyst in the potential application of environmental, biomedical and pharmaceutical samples.

An efficient photocatalyst for degradation of various organic dyes: Ag@Ag2MoO4-AgBr composite

The Ag2MoO4-AgBr composite was prepared by a facile in-situ anion-exchange method, then the Ag nanoparticles were coated on this composite through photodeposition route to form a novel Ag@Ag2MoO4-AgBr composite. The in-situ Br(-) replacement in a crystal lattice node position of Ag2MoO4 crystal allows for overcoming the resistance of electron transition effectively. Meanwhile silver nano-particles on the surface of Ag@Ag2MoO4-AgBr composite could act as electron traps to intensify the photogeneration electron-hole separation and the subsequent transfer of the trapped electron to the adsorbed O2 as an electron acceptor. As an efficient visible light catalyst, the Ag@Ag2MoO4-AgBr composite exhibited superior photocatalytic activity for the degradation of various organic dyes. The experimental results demonstrated superior photocatalytic rate of Ag@Ag2MoO4-AgBr composite compared to pure AgBr and Ag2MoO4 crystals (37.6% and 348.4% enhancement respectively). The Ag@Ag2MoO4-AgBr composite cloud degraded Rhodamin B, bromophenol blue, and amino black 10b completed in 7min.

Synthesis, antifungal evaluation and optical properties of silver molybdate microcrystals in different solvents: a combined experimental and theoretical study

In this study, we investigate the structure, antifungal activity, and optical properties of β-Ag₂MoO₄.

Mosaic structure effect and superior catalytic performance of AgBr/Ag2MoO4 composite materials

The research focused on mosaic style AgBr–Ag₂MoO₄ composite materials prepared by in situ composite method. The catalytic efficiency enhanced 149 times compared to pure Ag₂MoO₄. The success of instant catalysis owed to the mosaic structure effect.

Identifying and rationalizing the morphological, structural, and optical properties of [Formula: see text]-Ag2MoO4 microcrystals, and the formation process of Ag nanoparticles on their surfaces: combining experimental data and first-principles calculations

We present a combined theoretical and experimental study on the morphological, structural, and optical properties of β-Ag2MoO4 microcrystals. β-Ag2MoO4 samples were prepared by a co-precipitation method. The nucleation and formation of Ag nanoparticles on β-Ag2MoO4 during electron beam irradiation were also analyzed as a function of electron beam dose. These events were directly monitored in real-time using in situ field emission scanning electron microscopy (FE-SEM). The thermodynamic equilibrium shape of the β-Ag2MoO4 crystals was built with low-index surfaces (001), (011), and (111) through a Wulff construction. This shape suggests that the (011) face is the dominating surface in the ideal morphology. A significant increase in the values of the surface energy for the (011) face versus those of the other surfaces was observed, which allowed us to find agreement between the experimental and theoretical morphologies. Our investigation of the different morphologies and structures of the β-Ag2MoO4 crystals provided insight into how the crystal morphology can be controlled so that the surface chemistry of β-Ag2MoO4 can be tuned for specific applications. The presence of structural disorder in the tetrahedral [MoO4] and octahedral [AgO6] clusters, the building blocks of β-Ag2MoO4, was used to explain the experimentally measured optical properties.

Structural, morphological and optical investigation of β-Ag2MoO4 microcrystals obtained with different polar solvents

In this work, rietveld refinement, morphology and optical properties of β-Ag₂MoO₄ microcrystals were synthesized by the precipitation method using different polar solvents: water, methanol, ethanol, 1-propanol and 1-butanol.