WSe2/chitosan-based wearable multi-functional platform for monitoring electrophysiological signals, pulse rate, respiratory rate, and body movements.

A cleanroom free optimized fabrication of a low-cost facile tungsten diselenide (WSe2) combined with chitosan-based hydrogel device is reported for multifunctional applications including tactile sensing, pulse rate monitoring, respiratory rate monitoring, human body movements detection, and human electrophysiological signal detection. Chitosan being a natural biodegradable, non-toxic compound serves as a substrate to the semiconducting WSe2 electrode which is synthesized using a single step hydrothermal technique. Elaborate characterization studies are performed to confirm the morphological, structural, and electrical properties of the fabricated chitosan/WSe2 device. Chitosan/WSe2 sensor with copper contacts on each side is put directly on skin to capture human body motions. The resistivity of the sample was calculated as 26 kΩ m-1. The device behaves as an ultrasensitive pressure sensor for tactile and arterial pulse sensing with response time of 0.9 s and sensitivity of around 0.02 kPa-1. It is also capable for strain sensing with a gauge factor of 54 which is significantly higher than similar other reported electrodes. The human body movements sensing can be attributed to the piezoresistive character of WSe2 that originates from its non-centrosymmetric structure. Further, the sensor is employed for monitoring respiratory rate which measures to 13 counts/min for healthy individual and electrophysiological signals like ECG and EOG which can be used later for detecting numerous pathological conditions in humans. Electrophysiological signal sensing is carried out using a bio-signal amplifier (Bio-Amp EXG Pill) connected to Arduino. The skin-friendly, low toxic WSe2/chitosan dry electrodes pave the way for replacing wet electrodes and find numerous applications in personalized healthcare.

FePO4/WB as an efficient heterogeneous Fenton-like catalyst for rapid removal of neonicotinoid insecticides: ROS quantification, mechanistic insights and degradation pathways.

Iron-based catalysts for peroxymonosulfate (PMS) activation hold considerable potential in water treatment. However, the slow conversion of Fe(III) to Fe(II) restricts its large-scale application. Herein, an iron phosphate tungsten boride composite (FePO4/WB) was synthesized by a simple hydrothermal method to facilitate the Fe(III)/Fe(II) redox cycle and realize the efficient degradation of neonicotinoid insecticides (NEOs). Based on electron paramagnetic resonance (EPR) characterization, scavenging experiments, chemical probe approaches, and quantitative tests, both radicals (HO• and SO4⋅-) and non-radicals (1O2 and Fe(IV)) were produced in the FePO4/WB-PMS system, with relative contributions of 3.02 %, 3.58 %, 6.24 %, and 87.16 % to the degradation of imidacloprid (IMI), respectively. Mechanistic studies revealed that tungsten boride (WB) promoted the reduction of FePO4, and the generated Fe(II) dominantly activated PMS through a two-electron transfer to form Fe(IV), while a minority of Fe(II) engaged in a one-electron transfer with PMS to produce SO4⋅-, HO•, and 1O2. In addition, four degradation pathways of NEOs were proposed by analyzing the byproducts using UPLC-Q-TOF-MS/MS. Besides, seed germination experiments revealed the biotoxicity of NEOs was significantly reduced after degradation via the FePO4/WB-PMS system. Meanwhile, the recycling experiments and continuous flow reactor experiments showed that FePO4/WB exhibited high stability. Overall, this study provided a new perspective on water remediation by Fenton-like reaction. ENVIRONMENTAL IMPLICATION: Neonicotinoids (NEOs) are a type of insecticide used widely around the world. They've been found in many aquatic environments, raising concerns about their possible negative effects on the environment and health. Iron-based catalysts for peroxymonosulfate (PMS) activation hold great promise for water purification. However, the slow conversion of Fe(III) to Fe(II) restricts its large-scale application. Herein, iron phosphate tungsten boride composite (FePO4/WB) was synthesized by a simple hydrothermal method to facilitate the Fe(III)/Fe(II) redox cycle and realize the efficient degradation of NEOs. The excellent stability and reusability provided a great prospect for water remediation.

Synthesis and photodegradation performance of a heterostructure ferromagnetic photocatalyst based on MWCNTs functionalized with (3-glycidyloxypropyl)trimethoxysilane and decorated with tungsten trioxide for metronidazole and acetaminophen degradation in aqueous environments.

The presence of metronidazole (MNZ) and acetaminophen (ACE) in aquatic environments has raised growing concerns regarding their potential impact on human health. Incorporating various patterns into a photocatalytic material is considered a critical approach to achieving enhanced photocatalytic efficiency in the photocatalysis process. In this study, WO3 nanoparticles, which were immobilized onto ferromagnetic multi-walled carbon nanotubes that were functionalized using (3-glycidyloxypropyl)trimethoxysilane (FMMWCNTs@GLYMO@WO3), exhibited remarkable efficiency in removing MNZ and ACE (93% and 97%) in only 15 min. In addition, the new visible-light FMMWCNTs@GLYMO@WO3 nanoparticles as a magnetically separable photocatalyst were characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), EDS-mapping, vibrating sample magnetometry (VSM), thermogravimetric analysis (TGA), diffuse reflectance spectroscopy (DRS), high-performance liquid chromatography (HPLC), and total organic carbon (TOC) due to detailed studies (morphological, structural, magnetic and optical properties) of the photocatalyst. In-depth spectroscopic and microscopic characterization of the newly developed ferromagnetic FMMWCNTs@GLYMO@WO3 (III) photocatalyst revealed a spherical morphology, with nanoparticle diameters averaging between 23 and 39 nm. Compared to conventional multiwall carbon nanotube and WO3 photocatalysts, FMMWCNTs@GLYMO@WO3 (III) demonstrated superior photocatalytic activity. Remarkably, it exhibited excellent reusability, maintaining its efficiency over a minimum of five cycles in the degradation of metronidazole (MNZ) and acetaminophen (ACE).

Enhancing environmental sustainability: Butea monosperma leaves as a key component in WO3-based composites for water purification and therapeutic applications.

In this research, a novel nano-biocomposite material, namely, tungsten trioxide-Butea monosperma leaf powder (WO3@BLP), is an effective and eco-friendly adsorbent used for the mitigation of congo red (CR) and crystal violet (CV) dyes from its aqueous phase. The as-prepared WO3@BLP was characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), DLS analysis, and TGA. Many factors such as solution pH, WO3@BLP dose, temperature, contact time, and initial CR/CV dye concentrations were exploited to monitor the adsorption efficiency of WO3@BLP composites. The biosorption of both CR and CV dyes followed the Langmuir isotherm, with maximum adsorption capacities (qmax) reaching 84.91 mg g-1 for CR at pH 2.3 and 162.75 mg g-1 for CV at pH 8, fitting of kinetics data to the PSO model with closed values of qeexp (mg g-1) and qecal (mg g-1), i.e., 25.69 to 25.38 mg g-1 for CR dye and 29.06 to 29.08 mg g-1 for CV dye. The interaction mechanism behind the adsorption of CR and CV dyes onto the WO3@BLP bionanocomposite includes electrostatic interaction and surface complexation. The synthesized materials were tested for antifungal activity against three different Candida cells, i.e., C. albicans ATCC 90028, C. glabrata ATCC 90030, and C. tropicalis ATCC 750, by using broth dilution method on the minimum inhibiting concentration (MIC). Furthermore, the cytotoxicity of nano-formulated WO3@BLP was studied by in vitro hemolytic assay on a human host. Overall, this research presents a pioneering nano-biocomposite, WO3@BLP, as a sustainable adsorbent for CR and CV dye removal, adhering to Langmuir isotherm and pseudo-second-order kinetics. Its multifaceted approach includes elucidating interaction mechanisms, demonstrating antifungal activity, and assessing cytotoxicity, marking a significant advancement in environmental remediation.

Facile Fabrication of Lilac-Like Multiple Self-Supporting WO3 Nanoneedle Arrays with Cubic/Hexagonal Phase Junctions for Highly Sensitive Ethylene Glycol Gas Sensors.

Metal oxides with nanoarray structures have been demonstrated to be prospective materials for the design of gas sensors with high sensitivity. In this work, the WO3 nanoneedle array structures were synthesized by a one-step hydrothermal method and subsequent calcination. It was demonstrated that the calcination of the sample at 400 °C facilitated the construction of lilac-like multiple self-supporting WO3 arrays, with appropriate c/h-WO3 heterophase junction and highly oriented nanoneedles. Sensors with this structure exhibited the highest sensitivity (2305) to 100 ppm ethylene glycol at 160 °C and outstanding selectivity. The enhanced ethylene glycol gas sensing can be attributed to the abundant transport channels and active sites provided by this unique structure. In addition, the more oxygen adsorption caused by the heterophase junction and the aggregation of reaction medium induced by tip effect are both in favor of the improvement on the gas sensing performance.

Cefixime removal via WO3/Co-ZIF nanocomposite using machine learning methods.

In this research, an upgraded and environmentally friendly process involving WO3/Co-ZIF nanocomposite was used for the removal of Cefixime from the aqueous solutions. Intelligent decision-making was employed using various models including Support Vector Regression (SVR), Genetic Algorithm (GA), Artificial Neural Network (ANN), Simulation Optimization Language for Visualized Excel Results (SOLVER), and Response Surface Methodology (RSM). SVR, ANN, and RSM models were used for modeling and predicting results, while GA and SOLVER models were employed to achieve the optimal conditions for Cefixime degradation. The primary goal of applying different models was to achieve the best conditions with high accuracy in Cefixime degradation. Based on R analysis, the quadratic factorial model in RSM was selected as the best model, and the regression coefficients obtained from it were used to evaluate the performance of artificial intelligence models. According to the quadratic factorial model, interactions between pH and time, pH and catalyst amount, as well as reaction time and catalyst amount were identified as the most significant factors in predicting results. In a comparison between the different models based on Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Coefficient of Determination (R2 Score) indices, the SVR model was selected as the best model for the prediction of the results, with a higher R2 Score (0.98), and lower MAE (1.54) and RMSE (3.91) compared to the ANN model. Both ANN and SVR models identified pH as the most important parameter in the prediction of the results. According to the Genetic Algorithm, interactions between the initial concentration of Cefixime with reaction time, as well as between the initial concentration of Cefixime and catalyst amount, had the greatest impact on selecting the optimal values. Using the Genetic Algorithm and SOLVER models, the optimum values for the initial concentration of Cefixime, pH, time, and catalyst amount were determined to be (6.14 mg L-1, 3.13, 117.65 min, and 0.19 g L-1) and (5 mg L-1, 3, 120 min, and 0.19 g L-1), respectively. Given the presented results, this research can contribute significantly to advancements in intelligent decision-making and optimization of the pollutant removal processes from the environment.

Direct Z-scheme Cu2O/WO3/TiO2 nanocomposite as a potential supercapacitor electrode and an effective visible-light-driven photocatalyst.

This paper presents the synthesis of visible light-responsive ternary nanocomposites composed of cuprous oxide (Cu2O), tungsten trioxide (WO3), and titanium dioxide (TiO2) with varying weight percentages (wt.%) of the Cu2O. The resulting Cu2O/WO3/TiO2 (CWT) nanocomposites exhibited band gap energy ranging from 2.35 to 2.90 eV. Electrochemical and photoelectrochemical (PEC) studies confirmed a reduced recombination rate of photoexcited charge carriers in the CWT nanocomposites, facilitated by a direct Z-scheme heterojunction. The 0.50CWT nanocomposite demonstrated superior photodegradation activity (2.29 × 10-2 min-1) against Reactive Black 5 (RB5) dye under visible light activation. Furthermore, the 0.50CWT nanocomposite exhibited excellent stability with 80.51% RB5 photodegradation retention after five cycles. The 0.50CWT electrode achieved a maximum specific capacitance of 66.32 F/g at 10 mA/g current density, with a capacitance retention of 95.17% after 1000 charge-discharge cycles, affirming its stable and efficient supercapacitor performance. This was supported by well-defined peaks in cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) curves, indicating pseudocapacitive properties.

Ultrathin WO3 Nanosheets/Pd with Strong Metal-Support Interactions for Highly Sensitive and Selective Detection of Mustard-Gas Simulants.

Exposure to mustard gas can cause damage or death to human beings, depending on the concentration and duration. Thus, developing high-performance mustard-gas sensors is highly needed for early warning. Herein, ultrathin WO3 nanosheet-supported Pd nanoparticles hybrids (WO3 NSs/Pd) are prepared as chemiresistive sulfur mustard simulant (e.g., 2-chloroethyl ethyl sulfide, 2-CEES) gas sensors. As a result, the optimal WO3 NSs/Pd-2 (2 wt % of Pd)-based sensor exhibits a high response of 8.5 and a rapid response/recovery time of 9/92 s toward 700 ppb 2-CEES at 260 °C. The detection limit could be as low as 15 ppb with a response of 1.4. Moreover, WO3 NSs/Pd-2 shows good repeatability, 30-day operating stability, and good selectivity. In WO3 NSs/Pd-2, ultrathin WO3 NSs are rich in oxygen vacancies, offer more sites to adsorb oxygen species, and make their size close to or even within the thickness of the so-called electron depletion layer, thus inducing a large resistance change (response). Moreover, strong metal-support interactions (SMSIs) between WO3 NSs and Pd nanoparticles enhance the catalytic redox reaction performance, thereby achieving a superior sensing performance toward 2-CEES. These findings in this work provide a new approach to optimize the sensing performance of a chemiresistive sensor by constructing SMSIs in ultrathin metal oxides.

Novel pyrochlore type europium stannate - tungsten disulfide heterostructure for light driven carbon dioxide reduction and nitrogen fixation.

The reduction of carbon dioxide (CO2) and nitrogen (N2) to value-added products is a substantial area of research in the fields of sustainable chemistry and renewable energy that aims at reducing greenhouse gas emissions and the production of alternative fuels and chemicals. The current work deals with the synthesis of pyrochlore-type europium stannate (Eu2Sn2O7: EuSnO), tungsten disulfide (WS2:WS), and novel EuSnO/WS heterostructure by a simple and facile co-precipitation-aided hydrothermal method. Using different methods, the morphological and structural analyses of the prepared samples were characterized. It was confirmed that a heterostructure was formed between the cubic EuSnO and the layered WS. Synthesized materials were used for photocatalytic CO2 and N2 reduction under UV and visible light. The amount of CO and CH4 evolved due to CO2 reduction is high in EuSnO/WS (CO = 104, CH4 = 64 µmol h-1 g-1) compared to pure EuSnO (CO = 36, CH4 = 70 µmol h-1 g-1) and WS (CO = 22, CH4 = 1.8 µmol h-1 g-1) under visible light. The same trend was observed even in the N2 fixation reaction under visible light, and the amount of NH4+ produced was found to be 13, 26, and 41 µmol h-1 g-1 in the presence of WS, EuSnO and EuSnO/WS, respectively. Enhanced light-driven activity towards CO2 and N2 reduction reactions in EuSnO/WS is due to the efficient charge separation through the formation of type-II heterostructure, which is in part associated with photocurrent response, photoluminescence, and electrochemical impedence spectroscopic (EIS) results. The EuSnO/WS heterostructure's exceptional stability and reusability may pique the attention of pyrochlore-based composite materials in photocatalytic energy and environmental applications.

Tungsten sulfide highly boosted Fe(III)/peroxymonosulfate system for rapid degradation of cyclohexanecarboxylic acid: Performance, mechanisms, and applications.

In this study, the Fe(III)/WS2/peroxymonosulfate (PMS) system was found to remove up to 97% of cyclohexanecarboxylic acid (CHA) within 10 min. CHA is a model compound for naphthenic acids (NAs), which are prevalent in petroleum industrial wastewater. The addition of WS2 effectively activated the Fe(III)/PMS system, significantly enhancing its ability to produce reactive oxidative species (ROS) for the oxidation of CHA. Further experimental results and characterization analyses demonstrated that the metallic element W(IV) in WS2 could provide electrons for the direct reduction of Fe(III) to Fe(II), thus rapidly activating PMS and initiating a chain redox process to produce ROS (SO4•-, •OH, and 1O2). Repeated tests and practical exploratory experiments indicated that WS2 exhibited excellent catalytic performance, reusability and anti-interference capacity, achieving efficient degradation of commercial NAs mixtures. Therefore, applying WS2 to catalyze the Fe(III)/PMS system can overcome speed limitations and facilitate simple, economical engineering applications.

Defect-engineered dual Z-scheme core-shell MoS2/WO3-x/AgBiS2 for antibiotic and dyes degradation in photo and night catalysis: Mechanism and pathways.

Water pollution caused by antibiotics and synthetic dyes and imminent energy crises due to limited fossil fuel resources are issues of contemporary decades. Herein, we address them by enabling the multifunctionality in dual Z-scheme MoS2/WO3-x/AgBiS2 across photolysis, photo Fenton-like, and night catalysis. Defect, basal, and facet-engineered WO3-x is modified with MoS2 and AgBiS2, which extended its photoresponse from the UV-NIR region, inhibited carrier recombination, and reduced carrier transfer resistance. The electric field rearrangement leads to a flow of electrons from MoS2 and AgBiS2 to WO3-x and intensifies the electron population, which is crucial for night catalysis. When MoS2/WO3-x/AgBiS2 was employed against doxycycline hydrochloride (DOXH), it removed 95.65, 81.11, and 77.92 % of DOXH in 100 min during photo-Fenton (PFR), night-Fenton (NFR), and photocatalytic (PCR) reactions, respectively. It also effectively removed 91.91, 98.17, 99.01, and 98.99 % of rhodamine B (RhB), Congo red (CR), methylene blue (MB), and methylene orange (MO) in Fenton reactions, respectively. ESR analysis consolidates the ROS generation feature of MoS2/WO3-x/AgBiS2 using H2O2 with and without irradiation. This work provides a strategy to eliminate the deficiencies of WO3-x and is conducive to the evolution of applications seeking to combat environmental and energy crises.

Indoor-Light-Activated Blue TiO2-Molecule-WO3 Visible Photocatalyst for Antibacterial Performance against Escherichia coli.

Currently used visible light catalysts either operate with high-power light sources or require prolonged periods of time for catalytic reactions. This presents a limitation regarding facile application in indoor environments and spaces frequented by the public. Furthermore, this gives rise to elevated power consumption. Here, we enhance photocatalytic performance with blue TiO2 and WO3 complexes covalently coupled through an organic molecule, 3-mercaptopropionic acid, under indoor light. Antibacterial experiments against 108 CFU/mL Escherichia coli (E. coli) suspensions were conducted under indoor light exposure conditions. They showed a sterilization effect of almost 90% within 70 min and nearly 100% after 110 min. The complex generates reactive oxygen species (ROS), such as •OH and O2•-, under natural air conditions. We also showed that h+ and •OH are important for sterilizing E. coli using common scavengers. This research highlights the potential of these complexes to generate ROS, effectively playing a crucial role in antibacterial effects under indoor light.

Multifunctional Supramolecular Hydrogel Modulated Heterojunction Interface Carrier Transport Engineering Facilitates Sensitive Photoelectrochemical Immunosensing.

Highly responsive interface of semiconductor nanophotoelectrochemical materials provides a broad development prospect for the identification of low-abundance cancer marker molecules. This work innovatively proposes an efficient blank WO3/SnIn4S8 heterojunction interface formed by self-assembly on the working electrode for interface regulation and photoregulation. Different from the traditional biomolecular layered interface, a hydrogel layer containing manganese dioxide with a wide light absorption range is formed at the interface after an accurate response to external immune recognition. The formation of the hydrogel layer hinders the effective contact between the heterojunction interface and the electrolyte solution, and manganese dioxide in the hydrogel layer forms a strong competition between the light source and the substrate photoelectric material. The process effectively improves the carrier recombination efficiency at the interface, reduces the interface reaction kinetics and photoelectric conversion efficiency, and thus provides strong support for target identification. Taking advantage of the process, the resulting biosensors are being explored for sensitive detection of human epidermal growth factor receptor 2, with a limit of detection as low as 0.037 pg/mL. Also, this study contributes to the advancement of photoelectrochemical biosensing technology and opens up new avenues for the development of sensitive and accurate analytical tools in the field of bioanalysis.

WOx boosted hollow Ni nanoreactors for the hydrodeoxygenation of lignin derivatives.

Reasonable design of non-noble metal catalysts with hollow open structure for hydrodeoxygenation (HDO) of lignin derivatives to value-added chemicals is of great significance but challenging. Herein, a novel MOF-derived multilayer hollow sphere coated nickel­tungsten bimetallic catalyst (Ni2-WOx@CN-700) was fabricated via by confined pyrolysis strategy using bimetallic MOFs as a self-sacrificial template, which exhibits robust activity for the typical model HDO of vanillin to 2-methoxy-4-methylphenol (Yield of 100 % at 140 °C for no less than 10 cycles). The characterizations revealed that WOx facilitated the dispersion of Ni nanoparticles and adjusted the acidic capacity of the catalyst through the formed Ni-WOx heterojunction. Density functional theory (DFT) calculations confirms that WOx species enhanced the electron-rich nature of the active sites, while the adsorption energies of H2 and vanillin on Ni-WOx decreased from -0.572 eV and - 0.622 eV on Ni to -3.969 eV and - 4.922 eV, respectively. These results further indicated that the high activity of Ni2-WOx@CN-700 was attributed to the Ni-WOx heterojunction. Based on the characterizations and the thermodynamic calculations, the reaction mechanism was proposed. In addition, the catalyst shows good substrate universality, which enables its good commercial application prospect.

Self-powered photoelectrochemical aptasensor for fumonisin B1 detection based on a Z-scheme ZnIn2S4/WO3 photoanode.

The incidence of esophageal cancer is positively associated with fumonisin contamination. It is necessary to develop methods for the rapid detection of fumonisins. In this work, a self-powered photoelectrochemical aptamer sensor based on ZnIn2S4/WO3 photoanode and Au@W-Co3O4 photocathode is proposed for the sensitive detection of fumonisin B1 (FB1). Among them, under visible light irradiation, the Z-type heterostructure of ZnIn2S4/WO3 acts as a photoanode to improve the electron transfer rate, which contributes to the enhancement of the photocathode signal and lays the foundation for a wider detection range. The Au@W-Co3O4 photocathode as a sensing interface reduces the probability of false positives (comparison of anode sensing platforms). The PEC sensor has a good working performance in the detection range (10 pg/mL-1000 ng/mL) with a detection limit of 2.7 pg/mL (S/N = 3). In addition, the sensor offers good selectivity, stability and excellent recoveries in real sample analysis. This work is expected to play a role in the field of analyzing environmental toxins.

Synergistic utilization of industrial solid wastes: Extraction of valuable metals from tungsten leaching residue by photovoltaic sawing waste.

Solid waste challenges in both the tungsten and photovoltaic industries present significant barriers to achieving carbon neutrality. This study introduces an innovative strategy for the efficient extraction of valuable metals from hazardous tungsten leaching residue (W-residue) by leveraging photovoltaic silicon kerf waste (SKW) as a silicothermic reducing agent. W-residue contains 26.2% valuable metal oxides (WO3, CoO, Nb2O5, and Ta2O5) and other refractory oxides (SiO2, TiO2, etc.), while micron-sized SKW contains 91.9% Si with a surface oxide layer. The impact of SKW addition on the silicothermic reduction process for valuable metal oxides in W-residue was investigated. Incorporating SKW and Na2CO3 flux enables valuable metal oxides from W-residue to be effectively reduced and enriched as a valuable alloy phase, with unreduced refractory oxides forming a harmless slag phase during the Na2O-SiO2-TiO2 slag refining process. This process achieved an overall recovery yield of valuable metals of 91.7%, with individual recovery yields of W, Co, and Nb exceeding 90% with the addition of 8 wt.% SKW. This innovative approach not only achieves high-value recovery from W-residue and utilization of SKW but also minimizes environmental impact through an efficient and eco-friendly recycling pathway. The strategy contributes significantly to the establishment of a resource-efficient circular economy, wherein the recovered high-value alloy phase return to the tungsten supply chain, and the harmless slag phase become raw materials for microcrystalline glass production.

Doping Engineering To Modulate Surface Plasmon Resonance and Enzyme-like Activities for Enhancing Photoacoustic Imaging-Guided Targeted Cancer Therapy in the Second Near-Infrared Window.

Biological imaging-guided targeted tumor therapy has been a soughtafter goal in the field of cancer diagnosis and treatment. To this end, we proposed a strategy to modulate surface plasmon resonance and endow WO3-x nanoparticles (NPs) with enzyme-like catalytic properties by doping Fe2+ in the structure of the NPs. Doping of the Fe2+ introduced oxygen vacancies into the structure of the NPs, inducing a red shift of the maximum absorption wavelength into the near-infrared II (NIR-II) region and enhancing the photoacoustic (PA) and photothermal properties of the NPs for more effective imaging-guided cancer therapy. Under NIR-II laser irradiation, the Fe-WO3-x NPs produced very strong NIR-II PA and photothermal effects, which significantly enhanced the PA imaging and photothermal treatment effects. On the other hand, Fe2+ in Fe-WO3-x could undergo Fenton reactions with H2O2 in the tumor tissue to generate ·OH for chemodynamic therapy. In addition, Fe-WO3-x can also catalyze the above reactions to produce more reactive oxygen species (ROS) and induce the oxidation of NADH to interfere with intracellular adenosine triphosphate (ATP) synthesis, thereby further improving the efficiency of cancer therapy. Specific imaging of tumor tissue and targeted synergistic therapy was achieved after ligation of a MUC1 aptamer to the surface of the Fe-WO3-x NPs by the complexing of -COOH in MUC1 with tungsten ions on the surface of the NPs. These results demonstrated that Fe-WO3-x NPs could be a promising diagnosis and therapeutic agent for cancer. Such a study opens up new avenues into the rational design of nanodiagnosis and treatment agents for NIR-II PA imaging and cancer therapy.

Engineering a staggered type-II Bi2WO6/WO3 heterojunction with improved photocatalytic activity in wastewater treatment.

In recent years, the removal organic pollutants from wastewater by advanced oxidation processes, especially photocatalysis, has become a meaningful approach due to its eco-friendliness and low cost. Herein, staggered type-II Bi2WO6/WO3 heterojunction photocatalysts were prepared by a facile hydrothermal route and investigated by modern physicochemical methods (X-ray diffraction, scanning electron microscopy, low-temperature nitrogen adsorption-desorption, and diffuse reflectance spectroscopy). The optimized BWOW-5 photocatalyst exhibited a H2O2-assisted photocatalytic methylene blue removal efficiency of 94.1% (k = 0.01414 min-1) within 180 min under optimal reaction conditions, which is much higher than that of unmodified Bi2WO6 and WO3 due to efficient separation of the photogenerated charge carriers. The trapping experiments demonstrated that photogenerated hydroxyl radicals and holes play a key role in the photodegradation reaction. Moreover, the optimized BWOW-5 heterojunction photocatalyst exhibited excellent activity in the H2O2-assisted degradation of other pollutants, namely phenol, isoniazid, levofloxacin, and dibenzothiophene with the removal rate of 63.1, 73.6, 95.0, and 72.4%, respectively. This investigation offers a design strategy for Bi2WO6-based multifunctional photocatalytic composites with improved activity for organic pollutant degradation.

Novel starch-tungsten (VI) oxide biocomposites: Preparation, characterization, and comparisons between experimental and theoretical photon attenuation coefficients.

This study synthesized biocomposites containing starch and WO3 at varying ratios of 10 %, 20 %, 30 %, 40 %, and 50 % and assessed their thermal and radiation-shielding properties. These biocomposites were characterized using Fourier-transform infrared spectroscopy, X-ray diffraction (XRD) analysis, particle-size distribution assessments, scanning electron microscopy-energy dispersive X-ray spectroscopy, and thermogravimetric analysis-differential thermogravimetry measurements. Furthermore, the linear attenuation coefficients of the biocomposites were experimentally measured using an NaI(Tl) gamma spectrometry system and theoretically computed using XCOM and GAMOS simulations for comparisons. The XRD and particle-size distribution profiles of the WO3.2H2O powder, respectively, demonstrated evident diffraction peaks and favorable pore-size distributions. Morphological characterizations revealed that the WO3 particles were homogeneously dispersed throughout the starch matrix without any agglomeration. Comparisons of the thermal degradation rates revealed that the pure starch and starch +50%WO3 biocomposite began decomposing at approximately 200°Cand 300 °C, respectively, indicating that increasing WO3 proportions enhanced thermal stability. Furthermore, the starch +50%WO3 biocomposite demonstrated the highest experimental linear attenuation coefficient, with a value of 0.2510 ± 0.0848 cm-1 at a gamma energy of 662 keV. Meanwhile, XCOM and GAMOS simulations revealed theoretical attenuation coefficients of 0.1229 and 0.1213 cm-1 for pure starch and 0.2202 cm-1 and 0.2178 cm-1 for the starch +50%WO3 biocomposite at 662 keV, respectively.

Novel Ag3PO4/ZnWO4-modified graphite felt electrode for photoelectrocatalytic removal of harmful algae: Performance and mechanism.

A novel Ag3PO4/ZnWO4-modified graphite felt electrode (AZW@GF) was prepared by drop coating method and applied to photoelectrocatalytic removal of harmful algae. Results showed that approximately 99.21% of chlorophyll a and 91.57% of Microcystin-LR (MCLR) were degraded by the AZW@GF-Pt photoelectrocatalytic system under the optimal operating conditions with a rate constant of 0.02617 min-1 and 0.01416 min-1, respectively. The calculated synergistic coefficient of photoelectrocatalytic algal removal and MC-LR degradation by the AZW@GF-Pt system was both larger than 1.9. In addition, the experiments of quenching experiments and electron spin resonance (ESR) revealed that the photoelectrocatalytic reaction mainly generated •OH and •O2- for algal removal and MC-LR degradation. Furthermore, the potential pathway for photoelectrocatalytic degradation of MC-LR was proposed. Finally, the photoelectrocatalytic cycle algae removal experiments were carried out on AZW@GF electrode, which was found to maintain the algae removal efficiency at about 91% after three cycles of use, indicating that the photoelectrocatalysis of AZW@GF electrode is an effective emergency algae removal technology.