Metals Ag Research Articles

Sphere-rod-like Ag/AgCl@Fe2O3 Z-scheme heterojunction as photocatalysts for efficient degradation of tetracycline under visible light irradiation

Integration of multi-functional components into one is urgent for creating a viable platform to improve photocatalytic efficiency for environmental treatment. Here, MIL-88B–NH2 (Fe) was firstly employed to capture Ag+ cation for the formation of AgCl@MIL-88B–NH2 (Fe), and then turned into the strongly coupled Ag/AgCl@Fe2O3 with sphere-rod-like structure. As prepared Z-scheme Ag/AgCl@Fe2O3 heterojunction exhibited outstanding photocatalytic performance of tetracycline (TC) with a removal efficiency of 94.9% and a reaction kinetics of 0.0272 min−1, superior to single Ag/AgCl or Fe2O3, which attributed to the broad light absorption range and accelerated electron-hole pair separation stemmed from the synergistic effect between surface plasmon resonance effect (SPR) of metal Ag and AgCl/Fe2O3 heterojunction. Meanwhile, Ag/AgCl@Fe2O3 was found to be highly catalytic in the degradation of TC even after consecutive runs. Moreover, active species trapping experiments combined with ESR techniques revealed that superoxide radical, hydroxyl radical, electron, and hole all were involved in photodegradation of TC process. Importantly, the degradation intermediate products of TC were revealed in depth by LC-MS, and a possible degradation pathway was further proposed. This work opens up new insights into the integration of functional composites for the construction of advanced photocatalysts applied in environmental purification.

Facile Synthesis of PVP-Coated Silver Nanoparticles and Evaluation of Their Physicochemical, Antimicrobial and Toxic Activity

This study focuses on the synthesis of silver nanoparticles (AgNPs) at different high concentrations and investigates their physicochemical properties, antimicrobial activity, and cytotoxicity. AgNPs were synthesized using the alcohol reduction process, involving the reduction of AgNO3 and its subsequent stabilization via PVP at 80 °C for 4 h. The AgNO3/PVP molar ratio and the average molecular weight were modified in this study. Characterization analyses revealed that the synthesized AgNPs exhibited characteristic surface plasmon resonance absorption peaks at approximately 415 nm, as observed in the UV–Vis spectrum. The results presented in X-ray diffractograms confirmed the face-centered cubic structure of metallic Ag in the nanoparticles. The nanoparticles demonstrated uniform size and shape, with controllable dimensions ranging from 3 to 800 nm. Regarding antimicrobial activity, the MIC solutions exhibited higher potency against the planktonic cells of Candida albicans. The determination of inhibition halos indicated that the silver nanoparticles had an impact on the microorganisms Streptococcus mutans, Candida albicans, and Actinomyces israelii. Furthermore, lower-concentration compositions showed reduced cytotoxic effects compared to higher-concentration particles. Based on the findings, it was concluded that the AgNO3/PVP molar ratio plays a crucial role in the production of AgNPs. These synthesized nanoparticles exhibit desirable physicochemical properties and demonstrate potential antimicrobial activity and controlled cytotoxicity.

O- and OH-induced dopant segregation in single atom alloy surfaces: A combined density functional theory and machine learning study

In this study, we identified the significant factors affecting adsorbate-induced segregation in single-atom alloy (SAA) surfaces by performing Density Functional Theory (DFT)-based calculations and machine learning (ML) methods. We used O and OH species, which are key reactants in oxygen reduction reactions (ORR), as test adsorbates. We constructed SAA surfaces using different transition metals (Ag, Au, Co, Cu, Ir, Ni, Pd, Pt, and Rh) and calculated their segregation energies with and without the adsorbates to predict the segregation tendency of the dopant atom. We examined a total of 44 features which comprised of the elemental, energetics, and electronic properties of the SAAs. We employed a two-stage feature selection to reduce the number of features to the most important features for model training. We found that the formation energies, metallic radius difference, the d-band centers of the dopant in the surface and subsurface layer, the difference in surface energy between the host and dopant atoms, and the difference in the total number of d-electrons between the host and dopant atoms influence the segregation energy of the dopant induced by O and OH. Using these selected features, we implemented linear regression (LR), support vector machine regression (SVR), Gaussian process regression (GPR), and extra trees regression (ETR) algorithms to predict the segregation energies in the presence of adsorbates. For both O- and OH-SAA systems, SVR models exhibited the best performance for predicting adsorbate-induced segregation energies. Among the surfaces we considered, we determined Rh-Au(111) as a potential catalyst for ORR based on the calculated adsorption energies of O and OH and segregation energies in the presence of these adsorbates.

Watching (De)Intercalation of 2D Metals in Epitaxial Graphene: Insight into the Role of Defects.

Intercalation forms heterostructures, and over 25 elements and compounds are intercalated into graphene, but the mechanism for this process is not well understood. Here, the de-intercalation of 2D Ag and Ga metals sandwiched between bilayer graphene and SiC are followed using photoemission electron microscopy (PEEM) and atomistic-scale reactive molecular dynamics simulations. By PEEM, de-intercalation "windows" (or defects) are observed in both systems, but the processes follow distinctly different dynamics. Reversible de- and re-intercalation of Ag is observed through a circular defect where the intercalation velocity front is 0.5nm s-1 ± 0.2nm s.-1 In contrast, the de-intercalation of Ga is irreversible with faster kinetics that are influenced by the non-circular shape of the defect. Molecular dynamics simulations support these pronounced differences and complexities between the two Ag and Ga systems. In the de-intercalating Ga model, Ga atoms first pile up between graphene layers until ultimately moving to the graphene surface. The simulations, supported by density functional theory, indicate that the Ga atoms exhibit larger binding strength to graphene, which agrees with the faster and irreversible diffusion kinetics observed. Thus, both the thermophysical properties of the metal intercalant and its interaction with defective graphene play a key role in intercalation.

Effects of Cu, Sn, and Ti doping on the interfacial properties of Ag-based filler metal/WC: First-principles study and experimental characterization

First-principles calculations were used to determine the formation energy, work of adhesion, and electronic structure of the interface of Ag-doped (Cu, Sn, and Ti)/WC, revealing the effect of doping atoms on the interfacial bonding behavior. Additionally, an active filler metal Ag–Cu–Sn–Ti was developed from the calculation results and applied to braze YG18 cemented carbide/40Cr steel joint. The interfacial structure and elemental diffusion behavior at the filler metal/WC interface were characterized. The doping of Cu and Ti at the interface contributes significantly to the stability of the interfacial structure and the improvement of the work of adhesion. The effect of doping of Sn atoms at different positions on interfacial stability and the work of adhesion is not obvious, and it can be doped into Ag alloys as a melting point depressant. The charge accumulation zone and atomic orbital hybridizations at the interface contributes to enhance the interface stability and the work of adhesion. The TEM analysis demonstrates that the diffusion behavior of Ti is particularly noticeable, aggregating at the Ag/WC interface and interacting with C to generate a TiC reaction layer, ultimately producing a WC/TiC/Ag interface structure.

Influence of Electron Beam Treatment on Structure and Phase Composition of TiB2–Ag Coating Deposited by Electrical Explosion Spraying

Due to many factors, the electrical explosion spraying process is not stable, which directly causes unstable coating quality and structure. Electron beam treatment may be used to improve the surface and modified structure of coatings sprayed by electrical explosions. In this study, a new TiB2–Ag metal matrix composite coating was deposited by electrical explosion spraying and modified by electron beam treatment. The prepared coatings were characterized by surface macro- and microanalysis, XDR, cross-section SEM, and TEM. The composition of the spray-coating phase differs from sample to sample. The electron beam treatment normalized the phase composition. Ag TiB2 B2O became the main phase in the modified coating. Increasing the pulse energy density and duration leads to a reduction in the low-melting Ag phase and the formation of copper contact phases due to heating and melting of the copper substrate by excess electron beam energy. The coating structure consists of a silver matrix and TiB2 inclusions. The electron beam treatment did not affect the structure; however, the microstructure of the coating transformed into a cellular crystallization structure. The silver matrix nanostructure was transformed into a nanocrystalline structure with an average crystal size ranging from tens to hundreds of nanometers.

Adsorption properties of noble-metal (Ag, Rh, or Au)-doped CeO2(1 1 0) to CO: A DFT + U study

Dissolved gas analysis (DGA) is an effective method for fault detection of oil-immersed transformers, and CO is one of the characteristic gases in insulation oil. Therefore, based on density functional theory, the adsorption properties of three noble metals (Ag, Rh, or Au)-doped CeO2 (110) to CO were studied in this paper. The adsorption energy, charge transfer, density of states (DOS), and deformation charge density (DCD) were calculated to analyze the adsorption behavior of CO on the material surface. The frontier molecular orbital, energy band structure, and desorption time were also calculated to evaluate the potential of the three doping systems as CO sensors. The results show that the adsorption properties of Ag-CeO2, Rh-CeO2, and Au-CeO2 to CO are significantly higher than that of pristine CeO2, with adsorption energies are −54.61, −85.78, −205.57 kJ/mol, respectively. However, Rh-CeO2 exhibits superior sensitivity and satisfactory recovery time towards CO compared with Ag-CeO2 and Au-CeO2. Rh-CeO2 also shows excellent selectivity to CO, which is a promising candidate material for CO sensors. The research conducted in this work is intended to contribute to dissolved gas analysis (DGA).

Antibacterial properties of metal nanoparticles–incorporated activated carbon composites produced from waste biomass precursor

Activated carbon-based composite materials, together with the well known antibacterial activity of metal nanoparticles, urged the performance of this study to prepare new antibacterial materials with antimicrobial activity, as an important step in fighting pathogenic organisms. Activated carbon derived from a waste source - almond shells - were combined with metal (Ag, Cu, Mg) nanoparticles, in order to obtain metal composite with desirable characteristics. The composites were obtained using one-step high-temperature hydro-pyrolysis and further impregnation of the metal from water solution. Investigation of the structure, chemical composition and morphology of obtained composites was carried out by scanning electron microscopy, XRD, XPS, elemental and BET analysis, before testing their antimicrobial activity. Strongest antibacterial effect against E. coli was observed when 10 % Cu Activated Carbon Composite (ACCCu) was used attaining 100 % reduction of microbial count even at the starting point. ACCAg, ACCMg and activated carbon only, demonstrated such effect after 24 h. Best results after treatment of S. aureus were achieved with ACCAg and ACCCu after 24 h.The results indicate that the antibacterial activity depends on the contact time, bacterial species, nature of the metal and metal concentration. The novel metal nanoparticles-incorporated activated carbon composites demonstrated very good antibacterial activity. The investigation provides novel materials with antibacterial properties for further development and potential application in hygiene devices.

Increasing the Added Value of Copper and Silver Metal from Printed Circuit Board Waste Using a Knelson Concentrator with Variations in Size and Centrifugal Force

The use of technology in Indonesia has resulted in an increasing demand for electronic and electrical goods, including printed circuit board (PCB) waste. Currently, PCB waste amounts to 20-50 million tons and continues to grow annually. Given that the composition of PCB waste consists of approximately 40% metals such as Ag, Cu, Fe, Au, Sn, and Mn, recycling PCB FR-2 waste can significantly increase its added value. One effective method is employing a concentration technique to recover these metals. This study aims to investigate the impact of particle size and centrifugal force variations on the content and recovery of Cu and Ag metals in PCB FR-2 waste using a Knelson concentrator. The concentration process involved three size variations: -63+100, -100+150, and-150#, along with three centrifugal force values: 60, 90, and 120 G Force. The results indicate that the size variation-100+150# and a centrifugal force value of 90 G Force exhibited effectiveness in recovering Cu and Ag metals, with a minimal mass loss of 3.9%. The Cu and Ag levels reached 67.49% and 0.18%, respectively, with recovery rates of 53.22% and 39.96%.

Observation of infrared interband luminescence in magnesium by femtosecond spectroscopy

Ultrafast luminescence in Mg was investigated in the infrared region, between 0.35 and 1.05 eV, and compared with the results for Al, using a luminescence upconversion technique. The luminescence intensity of these metals at 0.9 eV was higher than that of platinum with a similar surface roughness under the same excitation density. Although the Mg and Al are adjacent to each other in the periodic table and belong to “light metals,” having similar band structures, their luminescence spectra differ significantly. Pronounced peak structures were found for Mg and these were attributed to interband transitions within the conduction bands consisting of 3s and 3p orbitals overlapped on the intraband continuum, based on density functional theory band structure calculation. This result is in contrast to the interband luminescence in noble metals (Au, Ag, and Cu) under continuous-wave blue laser excitation, where the final states have been assigned to the d bands. A comparison of the spectra of rough and specular surfaces suggested that the surface roughness is not essential for mitigating wavenumber mismatch for intraband transitions. The luminescence from light metals, which are harmless to humans, will be attractive for biomedical applications.

Enhanced photocatalytic reaction activity of Cu2WS4/Ag2S composite photocatalyst

Coupling noble metal cocatalysts are considered to be one of the most effective approaches to improve photocatalytic performance, but their expensive price limits their practical application. Herein, a series of Cu2WS4/Ag2S nanocomposite photocatalysts were successfully synthesized by a simple ion exchange method using Ag2S as the cocatalyst. Compared with pure Cu2WS4 and Ag2S, the optimized 25 wt% Cu2WS4/Ag2S (CA25) nanocomposites exhibited excellent photocatalytic degradation capability of RhB (96 %,20 min). More importantly, the as-prepared CA25 sample showed a significant photocatalytic hydrogen yield (19.8 μmol/h), which is 9.4 times that of pure Cu2WS4. Systematic studies revealed that the introduction of Ag2S can not only broaden the light absorbance capacity of the composite photocatalyst, but also effectively improve the separation efficiency of the photogenerated carriers. In addition, our results showed that photogenerated electrons simultaneously reduce Ag2S into metallic Ag in the photocatalytic reaction process, that is, metallic Ag can act as the bridge to capture electrons and accelerate the transmission of photogenerated carriers, thus enabling further enhancement of photocatalytic performance. This work provides a new insight for the design of highly efficient composite photocatalysts, and highlights the important role of photocarrier separation in the photocatalytic process.

Green synthesis of Ag/CuO and Ag/ [formula omitted] nanoparticles for enhanced photocatalytic dye degradation, antibacterial, and antifungal properties

In the context of synthesizing metal doped metal oxide nanoparticles (NPs), green synthesis emerges as a reliable, sustainable, environmentally-friendly, and exceptional alternative to the more efficient and conventional chemical methods. In this study, we explored the co-precipitation method performed for the Caesalpinia pulcherrima (C.pulcherrima) flower extract high percentage of hydroxyl functional groups on terpenoid derivatives, reducing and encapsulating agents, and the stability of the Ag/CuO and Ag/ TiO2 NPs. The XRD patterns provided evidence of the highly crystalline structure of monoclinic CuO, tetragonal crystal structure, and face-centered cubic Ag metal, obtained to improve the nanosized 6 and 8 nm, which structural defects in the synthesis materials were determined by scanning and transmission electron microscopy (SEM and TEM), as well as by X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDX) analyze. The existence of Ag ions (Ag+), Ti4+ ions, and Cu2+ ions in CuO and TiO2 caused the reduction of carbonyl and hydroxide functional groups, thereby facilitating the efficient formation of nanostructures, as demonstrated by XPS and Fourier transform infrared spectroscopy (FTIR). The band gap analysis of Ag/CuO and Ag/TiO2 NPs revealed that they increased the catalytic activity of methylene blue (MB) dye degradation efficiency achieved by 86 and 94 %, respectively. Comparatively, Ag doped with CuO and TiO2 has a synergistic effect leading to in highly effective antimicrobial activity against P. aeruginosa and E. coli infections.

Nanotube-Like Electronic States in [5,5]-C90 Fullertube Molecules.

Fullertubes, that is, fullerenes consisting of a carbon nanotube moiety capped by hemifullerene ends, are emerging carbon nanomaterials whose properties show both fullerene and carbon nanotube (CNT) traits. Albeit it may be expected that their electronic states show a certain resemblance to those of the extended nanotube, such a correlation has not yet been found or described. Here it shows a scanning tunneling microscopy (STM) and spectroscopy (STS) characterization of the adsorption, self-assembly, and electronic structure of 2D arrays of [5,5]-C90 fullertube molecules on two different noble metal surfaces, Ag(111) and Au(111). The results demonstrate that the shape of the molecular orbitals of the adsorbed fullertubes corresponds closely to those expected for isolated species on the grounds of density functional theory calculations. Moreover, a comparison between the electronic density profiles in the bands of the extended [5,5]-CNT and in the molecules reveals that some of the frontier orbitals of the fullertube molecules can be described as the result of the quantum confinement imposed by the hemifullerene caps to the delocalized band states in the extended CNT. The results thus provide a conceptual framework for the rational design of custom fullertube molecules and can potentially become a cornerstone in the understanding of these new carbon nanoforms.

The effect of phonons-surface and grain-boundary scattering on electrical properties of metallic Ag

Explain in this study, thickness has an inverse relationship with electrical resistivity and a linear relationship with Grain boundary scattering. According to the (Fuchs-Sondheier, Mayadas-Shatzkces) model, grain boundary scattering leads To an Increase in electrical Resistivity. The surface scattering Coefficient of Ag, which Fuchs-Sondheier and Mayadas-Shatzkces measured at , Ag's grain boundary reflection coefficient , which Mayadas-Shatzkces measured at , If the concentration of material has an effect on metal's electrical properties, According to this silver is a good electrical conductor and is used frequently in electrical and electronic circuits.

Distribution of Ag, Au, Bi, Cu, and Mo in surface soils. Case study: Mitrovica region, Republic of Kosovo

ABSTRACT This article presents the results of a geochemical investigation of an anthropogenic group of metals (Ag, Au, Bi, Cu, and Mo) in the surface of the Mitrovica region, Republic of Kosovo. In order to determine their content and to evaluate the contamination level, 156 topsoil samples were collected in an area of 301.5 km2. The content of elements was determined by inductively coupled plasma-mass spectrometry. The results showed that the average content of Cu (42 mg/kg), Bi (1.5 mg/kg), Ag (0.44 mg/kg), and Au (2.7 μg/kg) exceeded their average content in European and world soils by 3.4 and 1.4 times; 3.0 and 7.5 times; 1.62 and 8.8 times and 2.7 and 1.8 times, respectively. The average Mo content (0.68 mg/kg) exceeded the average content in European soils by 1.09 times, while the average content in world soil was not exceeded. Copper levels exceeded the Dutch target value of 36 mg/kg in 152 km2 and the Dutch action value of 190 mg/kg in 6.2 km2 of the study area. The enrichment factor and geo-accumulation index values for the analysed elements indicate that their higher content is of anthropogenic origin, mainly due to lead and zinc mining and metallurgical activities in the study area. The quality of soils in the Mitrovica region varies from highly contaminated with copper and bismuth, with extremely high enrichment of Cu, Bi and Ag in the soils of the central zone (Zone I) and the urban soils of the cities of Zveçan and Mitrovica. Therefore, the establishment of a monitoring and treatment programme for contaminated soils in this zone would be necessary to protect human health .

Kinetics of Hydrogen Evolution Reaction on Monometallic Bulk Electrodes in Various Electrolytic Solutions

The hydrogen evolution reaction (HER) holds pivotal significance in electrochemical energy conversion. In this study, we present essential HER kinetic parameters encompassing nine metals (Ag, Au, Co, Cr, Fe, Ni, Pt, W, and Zn) evaluated within seven distinct electrolytes (0.1 mol dm−3 HClO4, 0.1 mol dm−3 HCl, 0.5 mol dm−3 NaCl, 1 mol dm−3 KH2PO4, 0.1 mol dm−3 KOH, 0.1 mol dm−3 LiOH, and 1 mol dm−3 KOH). Through careful measures to restrain oxide formation, HER activity was measured on clean electrodes, while the assessment of HER activity on oxidatively treated metals was also performed. By correlating HER exchange current densities with calculated hydrogen binding energies, we show that the shape of HER volcano curves is largely preserved in studied electrolytes, at least around their apexes. Additionally, depending on the metal–electrolyte combination, the presence of surface oxide can have both positive and negative effects on HER kinetics. Finally, we collated HER kinetic data for bulk surfaces from diverse literature sources, offering a comprehensive overview of the kinetic parameters governing hydrogen evolution across distinct electrolytic environments. These insights have practical significance, guiding the development of new catalytic materials for different water electrolysis technologies, optimizing electrolyte formulations for boosting HER, and enhancing energy efficiency and catalytic performance through catalyst–electrolyte synergies.

Unlocking long-chain hydrocarbons (C2–7) via direct electrochemical CO2 and CO reduction on balanced Au/Ni electrodes

Electrochemical (EC) CO2 reduction method has been widely used as a green energy and environmental solution strategy. The use of Au/Ni electrodes was introduced to showcase a new concept of the direct EC Fischer-Tropsch (dEC F-T) synthesis pathway. This pathway involves the combination of electrodes that produce H2 and CO (syngas) during electrochemical CO2 reduction. The introduction of Au on the Ni electrode surface led to an increase in CO production and a gradual decrease in H2 production. When the interface was balanced, a pronounced F-T synthesis pathway was observed, resulting in the production of a series of hydrocarbons (CnH2n and CnH2n+2, n = 2–7). The dEC F-T synthesis was evaluated under different conditions, including electrolytes, concentrations, metal supports (Co and Fe), various overlayer metals (Ag and Cu), light irradiation, and isotope effects. The process was elucidated through surface C−C coupling polymerization reactions based on Anderson-Schulz-Flory weight distribution analysis. Additionally, the F-T synthesis was demonstrated through EC CO reduction via direct CO and H adsorption. The dEC F-T path provides a novel strategy for energy and environment by producing high-value long-chain hydrocarbons.

Improving the photocatalytic dye degradation performance and bactericidal properties of Brazilian Amazon Kaolin-waste by adding ZnO and Ag3PO4

New sustainable methodologies for the technological valorization of industrial residues are essential for reducing environmental problems and for obtaining materials with high added value. Herein, a microwave synthesis method was used to produce ZnO/Ag3PO4 supported in Kaolin clay (Kaolin/ZnO/Ag3PO4) and applied to Rhodamine B (RhB) dye degradation under visible light and tested as an antimicrobial agent. The calcination process at 200 ºC was performed to verify if the photocatalytic and antimicrobial properties were improved. The calcined sample (KZAgc) shows a constant rate approximately 1.8 times higher than the non-calcined form in RhB dye degradation. This improved performance can be attributed to the efficient separation of photogenerated charge carriers through a Z-scheme mechanism where metallic Ag nanoparticles act as the charge transmission bridge. KZAgc sample also showed a potent antimicrobial action against Candida albicans, Staphylococcus aureus, and Escherichia coli. Therefore, the data obtained in this work demonstrate that this nanocomposite can be efficiently used for the degradation of RhB under visible light, and its calcined form can be mainly used in various environmental and medical applications due to its superior antimicrobial performance.

Uptake of Silver-Containing Nanoparticles in an Estuarine Plant: Speciation and Bioaccumulation.

Understanding the bioaccumulation of silver-containing nanoparticles (Ag-NPs) with different species, concentrations, and sizes in estuarine plants is critical to their related environmental risk. Herein, the distribution of Ag-NPs in tidewater, sediments, and plants (Scirpus triqueter) of field-constructed mesocosm was investigated, where tidewater was exposed to Ag0-NPs and Ag+ at environmentally relevant concentrations. Particle number concentrations (PNCs) and sizes of Ag-NPs with various species were analyzed using a multistep selective dissolution method followed by the single-particle- inductively coupled plasma mass spectrometry technique. After 30 days of exposure, more than half of Ag0-NPs were dissolved to Ag+ and about 1/4 of Ag+ were transformed into Ag0-/AgCl-NPs in tidewater. Ag-NPs in stems exposed to Ag0-NPs were found to be dominated by metallic Ag, while Ag+ exposure led to more Ag2S-NPs in stems. In roots, 71% and 51% of Ag-NPs were found as Ag2S-NPs for Ag0-NPs and Ag+ treatment groups, respectively. Plant stems had a significantly higher enrichment of Ag-NPs than roots. Based on both random forests and structure equation models, it is suggested that salinity of tidewater can regulate Ag0-NPs in tidewater indirectly by influencing AgCl-NPs in tidewater and further affect the total PNCs of Ag-NPs in plant stems. Moreover, elevated sulfate-reducing bacteria (SRB) result in more Ag2S-NPs in rhizosphere sediments, thereby enhancing the bioaccumulation of Ag-NPs by roots.

Excellent photocatalytic and antibacterial performance of silver and cobalt doped MnO nanoparticles

Metals (Ag, Fe, Co and Ag+Co)-doped MnO nanoparticles are synthesized by sol–gel method and are investigated for photocatalytic and antibacterial activities. The synthesized nanoparticles are characterized by x-ray diffraction (XRD) and scanning electron microscopic (SEM) techniques to determine the structural and morphological properties. The XRD results indicate the successful incorporation of the doped-metal elements into the lattice and changes in the crystallite sizes. The SEM micrographs indicate nano-porous and agglomerated grains after the doping and maximum nano-porosity is estimated for Co and Ag+Co doped nanoparticles. Methylene-blue (MB) dye is used to measure the photocatalytic activity which indicates the degradation of 94% for Ag+Co doped nanoparticles in only 30 min. The antibacterial activities of the nanoparticles are investigated against pathogenic bacteria by using the cultures of Bacillus, Escherichia Coli, Streptococcus and Cocci. The dose quantities are varied and compared with the standard Amikacin medicine that is commercially used for antifungal treatment. It is found that inhibition zones increase up to five times than the standard against Bacillus, Escherichia Coli and Cocci and doubles for Streptococcus at the dose level higher than 20 μl. These results indicate that Ag+Co doped MnO nanoparticles show the excellent photocatalytic performance and the best antibacterial results against the Bacillus bacteria.