Tungsten Oxide WO3 Research Articles

Investigation the Gamma Ray Shielding Parameters for Portland Cement Doped with Several Metal Oxides

In this research, gamma ray photons emitted from radioactive sources (Cs-137, Ra-226) with energies (186, 242, 295, 352, 609, 662, 1120, 1765) keV, respectively, to study some parameters, Such as the linear attenuation coefficient ( , mass attenuation coefficient ( for shield made of composite materials consisting of cement as the base material reinforced with different materials (magnesium oxide MgO , tungsten oxide WO3) nanoparticles with different reinforcement ratios (10, 30, 50) % and thickness (0.5) cm to protect against radiation. For this purpose, a sodium iodide detector activated with thallium with dimensions ( was used with an integrated measuring system, to determine the suitability of these shields for use in the field of gamma ray protection. The results showed that the values ​​of these parameters are affected by changing the reinforcement ratios and the gamma ray energy. It was found that when increasing the reinforcement ratio of the shield led to an increase in the linear and mass attenuation coefficient, and in contrast, a decrease in the values ​​of each occurs when the gamma ray energy of the used radioactive source is increased, especially at a concentration of 50 % and at energy (1765) Kev.

Facile synthesis of Fe2O3, Fe2O3@CuO and WO3 nanoparticles: characterization, structure determination and evaluation of their biological activity

Due to their high specific surface area and its characteristic’s functionalized nanomaterials have great potential in medical applications specialty, as an anticancer. Herein, functional nanoparticles (NPs) based on iron oxide Fe2O3, iron oxide modified with copper oxide Fe2O3@CuO, and tungsten oxide WO3 were facile synthesized for biomedical applications. The obtained nanomaterials have nanocrystal sizes of 35.5 nm for Fe2O3, 7 nm for Fe2O3@CuO, and 25.5 nm for WO3. In addition to octahedral and square nanoplates for Fe2O3, and WO3; respectively. Results revealed that Fe2O3, Fe2O3@CuO, and WO3 NPs showed remarked anticancer effects versus a safe effect on normal cells through cytotoxicity test using MTT-assay. Notably, synthesized NPs e.g. our result demonstrated that Fe2O3@CuO exhibited the lowest IC50 value on the MCF-7 cancer cell line at about 8.876 µg/ml, compared to Fe2O3 was 12.87 µg/ml and WO3 was 9.211 µg/ml which indicate that the modification NPs Fe2O3@CuO gave the highest antiproliferative effect against breast cancer. However, these NPs showed a safe mode toward the Vero normal cell line, where IC50 were monitored as 40.24 µg/ml for Fe2O3, 21.13 µg/ml for Fe2O3@CuO, and 25.41 µg/ml for WO3 NPs. For further evidence. The antiviral activity using virucidal and viral adsorption mechanisms gave practiced effect by viral adsorption mechanism and prevented the virus from replicating inside the cells. Fe2O3@CuO and WO3 NPs showed a complete reduction in the viral load synergistic effect of combinations between the tested two materials copper oxide instead of iron oxide alone. Interestingly, the antimicrobial efficiency of Fe2O3@CuO NPs, Fe2O3NPs, and WO3NPs was evaluated using E. coli, S. aureus, and C. albicans pathogens. The widest microbial inhibition zone (ca. 38.45 mm) was observed with 250 mg/ml of WO3 NPs against E. coli, whereas using 40 mg/ml of Fe2O3@CuO NPS could form microbial inhibition zone ca. 32.86 mm against S. aureus. Nevertheless, C. albicans was relatively resistant to all examined NPs. The superior biomedical activities of these nanostructures might be due to their unique features and accepted evaluations.

Resistance Modulation of Individual and Polymicrobial Culture of S. aureus and E. coli through Nanoparticle-Coupled Antibiotics.

Polymicrobial mastitis is now becoming very common in dairy animals, resulting in exaggerated resistance to multiple antibiotics. The current study was executed to find drug responses in individual and mixed Culture of Staphylococcus aureus and Escherichia coli isolated from milk samples, as well as to evaluate the antibacterial potential of tungsten oxide nanoparticles. These isolates (alone and in mixed culture) were further processed for their responses to antibiotics using the disc diffusion method. On the other hand, tungsten oxide WO3 (W) nanoparticles coupled with antibiotics (ampicillin, A, and oxytetracycline, O) were prepared through the chemical method and characterized by X-ray diffraction, scanning electron microscopy (SEM), and UV-visible techniques. The preparations consisting of nanoparticles alone (W) and coupled with ampicillin (WA) and oxytetracycline (WO) were tested against individual and mixed Culture through the well diffusion and broth microdilution methods. The findings of the current study showed the highest resistance in E. coli was against penicillin (60%) and ampicillin (50%), while amikacin, erythromycin, ciprofloxacin, and oxytetracycline were the most effective antibiotics. S. aureus showed the highest resistance against penicillin (50%), oxytetracycline (40%), and ciprofloxacin (40%), while, except for ampicillin, the sensitive strains of S. aureus were in the range of 40-60% against the rest of antibiotics. The highest zones of inhibition (ZOI) against mixed Culture were shown by imipenem and ampicillin, whereas the highest percentage decrease in ZOI was noted in cases of ciprofloxacin (-240%) and gentamicin (-119.4%) in comparison to individual Culture of S. aureus and E. coli. It was noteworthy that the increase in ZOI was not more than 38% against mixed Culture as compared to the individual Culture. On the other hand, there was a significant reduction in the minimum inhibitory concentration (MIC) of nanoparticle-coupled antibiotics compared to nanoparticles alone for individual and mixed-culture bacteria, while MICs in the case of mixed Culture remained consistently high throughout the trial. This study therefore concluded that diverse drug resistance was present in both individual and mixed-culture bacteria, whereas the application of tungsten oxide nanoparticle-coupled antibiotics proved to be an effective candidate in reversing the drug resistance in bacterial strains.

Features of the Interaction of Scheelite with HCl Solutions at 400 and 500°C, 100 MPa, and Various f(O2) (According to Experimental and Calculated Data)

Experimental studies were carried out on the solubility of scheelite in HCl solutions in the concentration range from 0.01 to 0.316 mol/kg H2O at 400 and 500°C, a pressure of 100 MPa and the fugacity of oxygen (hydrogen) specified by the buffers Cu2O–CuO, Fe3O4–Fe2O3, Ni–NiO, and Co–CoO. It was found that scheelite in HCl solutions at the specified parameters dissolves incongruently. In solutions containing from 0.01 to 0.0316 m HCl, minor amounts of WO3 and/or WO3 – x tungsten oxides are found in the run products, along with scheelite. In solutions containing from 0.1 to 0.316 m HCl, the formation of calcium tungsten bronzes CaxWO3 is observed, the average composition of which corresponds to the formula Ca0.07WO3. Based on the analysis of the experimental data obtained, the free energies of the formation of tungsten oxides WO3, WO2.9, scheelite, and calcium tungsten bronze were calculated. Using mutually agreed thermodynamic data, the solubility of Sch in solutions of HCl and (Na, K)Cl with the participation of aluminosilicates is calculated. It is shown that the scheelite has a wide area of congruent solubility in saline systems.

FEATURES OF THE INTERACTION OF SHEELITE WITH HCl SOLUTIONS AT 400 AND 500 ° C, 100 MPa AND VARIOUS f(O2) (ACCORDING TO EXPERIMENTAL AND CALCULATED DATA)

Experimental studies were carried out on the solubility of scheelite in HCl solutions in the concentration range from 0.01 to 0.316 mol•kg-1 H2O at 400 and 500°C, a pressure of 100 MPa and the fugacity of oxygen (hydrogen) specified by the buffers Cu2O-CuO, Fe3O4-Fe2O3, Ni-NiO and Co-CoO. It was found that scheelite in HCl solutions at the specified parameters dissolves incongruently. In solutions containing from 0.01 to 0.0316 m HCl, minor amounts of tungsten oxides WO3 and (or) WO3-x are found in the run products, along with scheelite. In solutions containing from 0.1 to 0.316 m HCl, the formation of calcium tungsten bronzes (CTB) CaxWO3 is observed, the average composition of which corresponds to the formula Ca0.07WO3. Based on the analysis of the experimental data obtained, the free energies of the formation of tungsten oxides WO3, WO2.9, scheelite and calcium of tungsten bronze were calculated. Using mutually agreed thermodynamic data, the solubility of Sch in solutions of HCl, (Na,K)Cl with the participation of alumino-silicates is calculated. It is shown that the scheelite has a wide area of congruent solubility in saline systems.

Synthesis of mica supported tungsten oxide nanoparticles and their photocatalytic, biological and antioxidant activity

ABSTRACT Mica-supported tungsten oxide (M/WO3) and neat WO3 nanoparticles (NPs) were synthesised through acid precipitation method and then used as photocatalysts for degradation of Methyl Violet (MV) dye in aqueous media. The scanning electron microscopy (SEM) shows that the majority of WO3 NPs have cubical shape. The SEM micrographs also illustrated that the particles are mostly present in dispersed form, while some are in agglomerated form. The transmission electron microscopy (TEM) presented that the size of the nanoparticles were below 100 nm. The formation of NPs were also confirmed by energy dispersive X-ray (EDX), X-ray diffraction (XRD) and Fourier transform infra-red (FT-IR). The photodegradation study presented that WO3 and M/WO3 NPs degraded about 87% and 97% of MV dye within 75 min irradiation time under UV light. The recovered and re-recovered M/WO3 and WO3 NPs also significantly degraded MV dye. Both WO3 and M/WO3 NPs showed significant bio-activities against two pathogenic bacteria (Citrobacter and Providencia). Further, both types of NPs showed effective antioxidant activity.

Laser-induced electron transfer desorption/ionization on MoO3 and WO3 surfaces for the determination of dithiocarbamates.

Surface layers of molybdenum oxide MoO3 and tungsten oxide WO3 produced by thermal oxidation of molybdenum and tungsten plates in the air were studied for the first time as a platform for laser-induced electron transfer desorption/ionization. High analytical performance of such layers for the determination of metal complexes with dithiocarbamates, such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, and diethyldithiocarbamate, has been demonstrated. All studied complexes are detected as radical cations, with no fragment ions. The ion yields from MoO3 and WO3 surfaces were found to be more than two orders of magnitude higher than those from nanocrystalline silicon surfaces. A novel method has been developed for the determination of trace amounts of dithiocarbamates based on the complexation of analytes with gold ions, followed by laser-induced electron transfer desorption/ionization. The limits of detection of dithiocarbamates were estimated to be about 1ng/mL. The proposed method was successfully applied to the rapid screening of tetramethylthiuram disulfide residues in juice.

Toward Effective CO2 Reduction in an Acid Medium: Electrocatalysis at Cu2O-Derived Polycrystalline Cu Sites Immobilized within the Network of WO3 Nanowires.

A hybrid catalytic system composed of copper (I)-oxide-derived copper nanocenters immobilized within the network of tungsten oxide nanowires has exhibited electrocatalytic activity toward CO2 reduction in an acid medium (0.5 mol dm-3 H2SO4). The catalytic system facilitates conversion of CO2 to methanol and is fairly selective with respect to the competing hydrogen evolution. The preparative procedure has involved voltammetric electroreduction of Cu2O toward the formation and immobilization of catalytic Cu sites within the hexagonal structures of WO3 nanowires which are simultaneously partially reduced to mixed-valence hydrogen tungsten (VI, V) oxide bronzes, H x WO3, coexisting with sub-stoichiometric tungsten (VI, IV) oxides, WO3-y . After the initial loss of Cu through its dissolution to Cu2+ during positive potential scanning up to 1 V (vs RHE), the remaining copper is not electroactive and seems to be trapped within in the network of hexagonal WO3. Using the ultramicroelectrode-based probe, evidence has also been provided that partially reduced nonstoichiometric tungsten oxides induce reduction of CO2 to the CO-type reaction intermediates. The chronocoulometric data are consistent with the view that existence of copper sites dispersed in WO3 improves electron transfers and charge propagation within the hybrid catalytic layer. The enhanced tolerance of the catalyst to the competitive hydrogen evolution during CO2R should be explained in terms of the ability of H x WO3 to consume protons and absorb hydrogen as well as to shift the proton discharge at Cu toward more negative potentials. However, the capacity of WO3 to interact with catalytic copper and to adsorb CO-type reaction intermediates is expected to facilitate removal of the poisoning CO-type adsorbates from Cu sites.

Tungsten Bronzes ΑxWO3 (A=Li, Na or K) As Electrodes for Fast Aqueous Batteries

Aqueous batteries, asymmetric supercapacitors and hybrid devices using oxides as electrodes have been envisioned for stationary applications due to their low environmental impact and the easiness to recycle oxides when operated in a water based electrolyte [1]. This is especially true when neutral pH electrolytes are used. Quite a lot of positive electrode oxides have been proposed up to now but it seems more difficult to combine high capacity and low potential electrochemical window for negative electrodes [2]. In the present study we propose tungsten oxide WO3 as a potential candidate for negative electrode of mild aqueous electrolyte energy storage device. More specifically the metastable phase of hexagonal bronze (h-WO3) was targeted. This phase cannot be obtained by purely structural transformation upon temperature [3]. This structure possesses a rigid tungsten-oxygen framework built up of layers containing corner-shared WO6 octahedra that are arranged in six-membered rings. The layers are stacked along the [00l] axis, giving rise to one-dimensional tunnels being able to host different alkali cations such as Li+, Na+, and K+ [4]. This arrangement can result in interesting electrochemical properties when used as electrode materials for energy storage devices [5].Hexagonal tungsten oxides with the general formula AxWO3 (A= Li, Na, or K and 0 < x < 0.33) were successfully synthesized by hydrothermal synthesis. The materials were characterized by X-ray Diffraction, Scanning and Transmission Electron Microscopy, Energy dispersive X-ray spectroscopy, and BET specific surface area measurements. Their electrochemical behaviors in different aqueous electrolytes such as LiNO3 (5M and 1M), Li2SO4, Na2SO4, and K2SO4. (0.5 M) were investigated and specific capacities up to ~80 C g-1 were measured. In this communication we will detail the electrochemical response of the different tungsten bronzes and we will give some more fundamental insights about the charge storage mechanisms using advanced characterization techniques.

Influence of the Iron as a Dopant on the Refractive Index of WO3.

Results on studies of pure tungsten oxide WO3 and 2, 3 and 4% Fe-doped WO3 grown on the sapphire substrates by reactive pulsed laser deposition technique are reported. From X-ray diffraction it results that the crystalline structures changed with the substrate temperature and the peaks diffraction having a small shift by the amount of Fe content in WO3 lattice was noticed. Scanning electron microscopy presented a random behavior of WO3 nanocrystallites size with substrate temperatures. In the presence of 2% Fe-doped WO3, the nanocrystallites size varied gradually from 60 nm to 190 nm as substrate temperature increased. The transmission spectra of the pure and 2, 3 and 4% Fe-doped WO3 films were obtained within the 300–1200 nm spectral range. The refractive index of WO3 and Fe-doped WO3 layers were calculated by the Swanepoel method. The refractive index of pure WO3 shows a variation from 2.35–1.90 and for 2% Fe-doped WO3 from 2.30–2.00, as the substrate temperature increased. The contents of 3 and 4% Fe-doped WO3 presented nearly identical values of the refractive index with pure and 2% Fe-doped WO3, in error limits, at 600 °C. The optical band gap changes with substrate temperature from 3.2 eV to 2.9 eV for pure WO3 and has a small variation with the Fe.

Novel Nanocombinations of l-Tryptophan and l-Cysteine: Preparation, Characterization, and Their Applications for Antimicrobial and Anticancer Activities.

Tungsten oxide WO3 nanoparticles (NPs) were prepared in a form of nanosheets with homogeneous size and dimensions in one step through acid precipitation using a cation exchange column. The resulting WO3 nanosheet surface was decorated with one of the two amino acids (AAs) l-tryptophan (Trp) or l-cysteine (Cys) and evaluated for their dye removal, antimicrobial, and antitumor activities. A noticeable improvement in the biological activity of WO3 NPs was detected upon amino acid modification compared to the original WO3. The prepared WO3-Trp and WO3-Cys exhibited strong dye removal activity toward methylene blue and safranin dyes with complete dye removal (100%) after 6 h. WO3-Cys and WO3-Trp NPs revealed higher broad-spectrum antibacterial activity toward both Gram-negative and Gram-positive bacteria, with strong antifungal activity toward Candida albicans. Anticancer results of the modified WO3-Cys and WO3-Trp NPs against various kinds of cancer cells, including MCF-7, Caco-2, and HepG-2 cells, indicate that they have a potent effect in a dose-dependent manner with high selectivity to cancer cells and safety against normal cells. The expression levels of E2F2 and Bcl-2 genes were found to be suppressed after treatment with both WO3-Cys and WO3-Trp NPs more than 5-FU-treated cells. While expression level of the p53 gene in all tested cells was up-regulated after treatment 5–8 folds more as compared to untreated cells. The docking results confirmed the ability of both NPs to bind to the p53 gene with relevant potency in binding to other tested gens and participation of cysteine SH-functional group in such interaction.

Microstructure and Sintering Behavior of Fine Tungsten Powders Synthesized by Ultrasonic Spray Pyrolysis

The powder microstructure and sintering behavior of W prepared by ultrasonic spray pyrolysis and spark plasma sintering were investigated. Fine-grained W powders were synthesized by ultrasonic spray pyrolysis using an ammonium metatungstate hydrate solution and hydrogen reduction. The XRD analysis of the powder, pyrolyzed below 600 oC, showed tungsten oxide hydrate and WO3 peaks, while the powder pyrolyzed at 700 oC was composed of only the WO3 phase. As the precursor concentration increased, the particle size of the WO3 powder increased, which was interpreted to be due to an increase in the amount of solute in the droplet. The hydrogen-reduced powder showed a spherical shape with fine pores inside. XRD and XPS analysis revealed that the WO3 powder was completely reduced to metallic W by hydrogen reduction, and some oxide layers existed on the powder surface. The consolidated specimen prepared by spark plasma sintering of hydrogen-reduced W powder exhibited a relative density of 94.1% and a Vickers hardness value of 3.89 GPa. The relative density and hardness of the specimens prepared by ultrasonic spray pyrolysis showed relatively lower values than when commercial W powder, with an average particle size of 1.22 μm, was sintered under the same conditions. These results were explained by the formation of agglomerates in the W powder prepared by the ultrasonic spray pyrolysis method.

Tuning the Optical Properties of WO3 Films Exhibiting a Zigzag Columnar Microstructure

Tungsten oxide WO3 thin films are deposited by DC reactive magnetron sputtering. The Reactive Gas Pulsing Process (RGPP) associated with the GLancing Angle Deposition method (GLAD) are implemented to produce zigzag columnar structures. The oxygen injection time (tON time) and the pulsing period are kept constant. Three tilt angles α are used: 75, 80, and 85° and the number of zigzags N is progressively changed from N = 0.5, 1, 2, 4, 8 to 16. For each film, refractive index, extinction coefficient, and absorption coefficient are calculated from optical transmission spectra of the films measured in the visible region from wavelength values only. Absorption and extinction coefficients monotonously drop as the number of zigzags increases. Refractive indices are the lowest for the most grazing tilt angle α = 85°. The highest refractive index is nevertheless obtained for a number of zigzags close to four. This optimized optical property is directly correlated to changes of the microstructure, especially a porous architecture, which is favored for high tilt angles, and tunable as a function of the number of zigzags.

Influence of tungsten nanopowders W, tungsten oxide WO3, tungsten carbide WC on changing radio protective properties of polymers

The paper considers the possibility of improving radio protective properties of polymers by modifying with nanopowders: tungsten W, tungsten oxide WO3, tungsten carbide WC, obtained from hard-alloy waste. The study determined the coefficients of linear attenuation of gamma radiation in the energy range of 59.93 keV…1408 keV at various concentrations of nanopowders 20…80% of the mass of the material, with a step of 20%. The comparative characteristic of the obtained data is given. The developed composite materials can be used in the systems of passive protection, dosimetry, space technology, as well as greatly facilitate the weight of various structural products.

Synthesis and characterization of WS2/SiO2 microfibers

Tungsten disulfide polycrystalline microfibers were successfully synthesized by a process involving electrospinning, calcination, and sulfidation steps. We used an aqueous solution of silicotungstic acid (H4SiW12O40) and polyvinyl alcohol as precursors for the synthesis of composite fibers by the needle-less electrospinning technique. The obtained green composite fibers (av. diam. 460 nm) were converted by calcination in air to tungsten oxide WO3 fibers with traces of SiO2 and a smaller diameter (av. diam. 335 nm). The heat treatment of the WO3 fibers under flowing H2/H2S/N2 stream led to conversion to tungsten disulfide WS2 with retention of the fibrous morphology (av. diam. 196 nm). Characterization of the intermediate and final fibers was performed by the XRD, SEM, TEM, HAADF STEM EDS, elemental analyses ICP-OES, and IR spectroscopy methods.

Magneli-type tungsten oxide nanorods as catalysts for the selective oxidation of organic sulfides.

Selective oxidation of thioethers is an important reaction to obtain sulfoxides as synthetic intermediates for applications in the chemical industry, medicinal chemistry and biology or the destruction of warfare agents. The reduced Magneli-type tungsten oxide WO3-x possesses a unique oxidase-like activity which facilitates the oxidation of thioethers to the corresponding sulfoxides. More than 90% of the model system methylphenylsulfide could be converted to the sulfoxide with a selectivity of 98% at room temperature within 30 minutes, whereas oxidation to the corresponding sulfone was on a time scale of days. The concentration of the catalyst had a significant impact on the reaction rate. Reasonable catalytic effects were also observed for the selective oxidation of various organic sulfides with different substituents. The WO3-x nanocatalysts could be recycled at least 5 times without decrease in activity. We propose a metal oxide-catalyzed route based on the clean oxidant hydrogen peroxide. Compared to other molecular or enzyme catalysts the WO3-x system is a more robust redox-nanocatalyst, which is not susceptible to decomposition or denaturation under standard conditions. The unique oxidase-like activity of WO3-x can be used for a wide range of applications in synthetic, environmental or medicinal chemistry.

Microwave Assisted Pure and Mg Doped Tungsten Oxide WO3 Nanoparticles for Superconducting Applications

Microwave Assisted Pure and Mg Doped Tungsten Oxide WO3 Nanoparticles for Superconducting Applications

Towards enhanced durability of electrochromic WO3 interfaced with liquid or ceramic sodium-based electrolytes

The reversible intercalation of sodium ion into tungsten oxide WO3 appears as an interesting alternative to hydrogen or lithium ion reduction in order to get the characteristic transition from clear transparent to bluish coloration in electrochromic devices, but it has been comparatively less considered. In order to address further viable all-ceramic devices based on sodium ion intercalation and overcome the issue of WO3 degradation in aqueous media, three configurations of WO3 thin film-based electrochromic half-cells were tested, namely in (i) aqueous acidified Na2SO4 electrolyte, (ii) room temperature ionic liquid BEPipTFSI electrolyte and (iii) aqueous acidified Na2SO4 electrolyte associated with an amorphous NASICON-cap onto WO3 film. We compared their electro-optical characteristics during 100 voltammetry cycles, including the Na+ diffusion coefficient calculated through electrochemical method. It is found that sputter-deposited amorphous WO3 thin films on transparent conductive substrates is promising for electrochromic all-ceramic devices based on Na ion insertion. Electrochemical characterization in aqueous medium is not relevant to extract relevant data when WO3 is in direct contact with the electrolyte as the electrochromic film is progressively dissolved. In contrast, WO3 capped with oxide amorphous Na-ion conductor readily operates over 100 cycles, the capping layer preventing degradation by the aqueous medium. Alternatively, ionic liquid does not degrade the WO3 film and can be employed to efficiently characterize the electro-optical performances.

Enhance thermal efficiency of parabolic trough collector using Tungsten oxide/Syltherm 800 nanofluid

Abstract:Development of thermal efficiency of the concentrated solar energy especially parabolic trough collector using various nanofluids types has a taken high interest in recent years. In this article enhancement thermal performance inside the heating collecting element of trough collector type LS-2 was simulated and improved using nanofluid consist of Tungsten Oxide WO3 inserting in Syltherm 800. Nanofluid effect was examined by solving the energy balance equation using MATLAB Software to cover wide range concentration volume 1-5% and inlet temperatures ranging from 350-650 K for the turbulent flow. The heat transfer performance and thermal efficiency were improved based on the results, and a notable increase was obtained when volume concentration had been increased compared with base fluid.

Designing Selective Electrode Materials for Electroanalysis –New Tungsten Bronzes as Selective Potassium Hosts

AbstractCommercially available monoclinic tungsten oxide WO3 (Pearson symbol mP32) is investigated electrochemically for its selectivity and sensitivity towards potassium ion detection. Electroreduction in aqueous potassium chloride solution shows two distinct phases, identified as tungsten bronzes KxWO3 (phase 1: maximum x1 0.1 and phase 2: maximum x2≈0.3). In situ synchrotron powder X‐ray diffraction reveals the concomitant structural changes, and both phases are identified as new, so far unreported, perovskite‐derived potassium bronzes (space group P4/nmm and I 3 m, respectively). In cyclic voltammetry, only the first insertion step is found to be reversible. Potentiostatic insertion and the subsequent voltammetric de‐insertion show selectivity toward potassium against lithium and sodium in 0.1 M aqueous solutions. The sensitivity towards potassium is analysed in a concentration range between 1 mM and 100 mM. Two linear regions are found for the response, which we relate to two different rate‐determining steps, depending on the concentration of potassium in solution.