Spatial confinement: An effective strategy to improve H2O and SO2 resistance of the expandable graphite-modified TiO2-supported Pt nanocatalysts for CO oxidation.

The expandable graphite (EG) modified TiO2 nanocomposites were prepared by the high shear method using the TiO2 nanoparticles (NPs) and EG as precursors, in which the amount of EG doped in TiO2 was 10 wt.%. Followed by the impregnation method, adjusting the pH of the solution to 10, and using the electrostatic adsorption to achieve spatial confinement, the Pt elements were mainly distributed on the exposed TiO2, thus generating the Pt/10EG-TiO2-10 catalyst. The best CO oxidation activity with the excellent resistance to H2O and SO2 was obtained over the Pt/10EG-TiO2-10 catalyst: CO conversion after 36 hr of the reaction was ca. 85% under the harsh condition of 10 vol.% H2O and 100 ppm SO2 at a high gaseous hourly space velocity (GHSV) of 400,000 hr-1. Physicochemical properties of the catalysts were characterized by various techniques. The results showed that the electrostatic adsorption, which riveted the Pt elements mainly on the exposed TiO2 of the support surface, reduced the dispersion of Pt NPs on EG and achieved the effective dispersion of Pt NPs, hence significantly improving CO oxidation activity over the Pt/10EG-TiO2-10 catalyst. The 10 wt.% EG doped in TiO2 caused the TiO2 support to form a more hydrophobic surface, which reduced the adsorption of H2O and SO2 on the catalyst, greatly inhibited deposition of the TiOSO4 and formation of the PtSO4 species as well as suppressed the oxidation of SO2, thus resulting in an improvement in the resistance to H2O and SO2 of the Pt/10EG-TiO2-10 catalyst.

Nano-TiO2/TiN Systems for Electrocatalysis: Mapping the Changes in Energy Band Diagram across the Semiconductor|Current Collector Interface and the Study of Effects of TiO2 Electrochemical Reduction Using UV Photoelectron Spectroscopy.

TiO2 is the most widely used material in photoelectrocatalytic systems. A key parameter to understand its efficacy in such systems is the band bending in the semiconductor layer. In this regard, knowledge on the band energetics at the semiconductor/current collector interface, especially for a nanosemiconductor electrode, is extremely vital as it will directly impact any charge transfer processes at its interface with the electrolyte. Since direct investigation of interfacial electronic features without compromising its structure is difficult, only seldom are attempts made to study the semiconductor/current collector interface specifically. This work utilizes ultraviolet photoelectron spectroscopy (UPS) to determine the valence band maximum (EVBM) and Fermi level (EF) at different depths in a nano-TiO2/TiN thin-film system reached using an Ar gas-clustered ion beam (GCIB). By combining UPS with GCIB depth profiling, we report an innovative approach for truly mapping the energy band structure across a nanosemiconductor/current collector interface. By coupling it with X-ray photoelectron spectroscopy (XPS), correlations among chemistry, chemical bonding, and electronic properties for the nano-TiO2/TiN interface could also be studied. The effects of TiO2 in situ electrochemical reduction in aqueous electrolytes are also investigated where UPS confirmed a decrease in the semiconductor work function (WF) and an associated increase in n-type Ti3+ centers of nano-TiO2 electrodes post use in a 0.2 M potassium chloride solution. We report the use of UPS to precisely determine the energy band diagrams for a nano-TiO2/TiN thin-film interface and confirm the increase in TiO2 n-type dopant concentrations during electrocatalysis, promoting a much more comprehensive and intuitive understanding of the TiO2 activation mechanism by proton intercalation and therefore further optimizing the design process of efficient photocatalytic materials for solar conversion.

Study of microstructure and corrosion behavior of nano-Al2O3 coating layers on TiO2 substrate via polymeric method and microwave combustion.

The study describes the successful development of a TiO2 ceramic substrate with a protective nano-Al2O3 coating using two different coating techniques: microwave combustion and polymeric methods. The coated ceramics demonstrate enhanced corrosion resistance compared to the uncoated substrate. The optimal TiO2 substrate was prepared by firing it at 1000 °C. This was done to give the desired physical properties of the TiO2 substrate for the coating procedures. Nano-Al2O3 powder was coated onto the surface of the TiO2 substrates. The TiO2 substrates with the Al2O3 coating were then calcined (heat-treated) at 800 and 1000 °C. The structures, morphology, phase composition, apparent porosity, bulk density, and compressive strength of the substrate and coated substrate were characterized. Upon firing at 1000 °C, it was discovered that the two phases of TiO2-rutile and anatase-combine in the substrate. Once the substrate has been coated with nano Al2O3 at 1000 °C, the anatase is transferred into rutile. When compared to the substrate, the coated substrate resulted in a decrease in porosity and an increase in strength. The efficiency of the ceramic metal nanoparticles Al2O3 as a good coating material to protect the TiO2 substrates against the effect of the corrosive medium 0.5 M solution of H2SO4 was measured by two methods: potentio-dynamic polarization (PDP) and the electrochemical impedance spectroscopy (EIS). The results indicated that the corrosion rate was decreased after the substrate coated with alumina from (67.71 to 16.30 C.R. mm/year) and the percentage of the inhibition efficiency recorded a high value reaching (78.56%). The surface morphology and composition after electrochemical measurements are investigated using SEM and EDX analysis. After conducting the corrosion tests and all the characterization, the results indicated that the coated TiO2 substrate prepared by the polymeric method at 800 °C displayed the best physical, mechanical, and corrosion-resistant behavior.

Clinical Efficacy of a Novel Titania Nanoparticle-Reinforced Bonding Agent in Reducing Post-Restorative Sensitivity: A randomized clinical trial.

Objective: To evaluate the clinical efficacy of novel titania-nanoparticle reinforced bonding agent on post-restorative sensitivity in patients. Methods: This triple-blinded, randomized clinical trial included participants (n = 60) having Class- I and II cavitations with a minimum cavity depth of 3mm at Department of Operative Dentistry & Endodontics, School of Dentistry, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad from January 5, 2023, to June 20, 2023. They were randomly assigned into two groups A and B (n = 30). After informed consent, restorative intervention was accomplished using an etch-and-rinse adhesive strategy. In Group-A, titania-nanoparticle-incorporated bonding agent was used for composite restoration, while in Group-B, bonding agent without nanoparticles was used. The primary outcome was assessed using Visual Analogue Scale mean score. Participants were instructed to rate their sensitivity status at follow-ups: 24 hours, one week, and one month. Mann-Whitney U test was employed to compare sensitivity between the two groups. Results: According to results of this trial, a significant difference was observed between two groups after 24 hours (p = 0.004) and one week (p = 0.002). However, no discernible difference was observed after one month (p = 0.643). Conclusion: Post-restorative sensitivity in patients with composite restorations was reduced using titania-reinforced bonding agents as compared to bonding agents without nanoparticles. This shows that inclusion of titania nanoparticles into adhesive dentistry could be beneficial in resolving post-restorative sensitivity occurring with composite restorations.

Biosynthesized and chemically synthesized Ag/TiO2 nanocomposites: Effect of reaction parameters on synthesis using watermelon rind extract and comparative analysis.

This work synthesized Ag/TiO2 nanocomposite via an aqueous reduction method using a green and chemical reducing agent. Citrullus lanatus (watermelon) rind extract (WMRE) and sodium borohydride (NaBH4) were used as the reducing agents during green synthesis and chemical synthesis, respectively. During green synthesis, a pH of 12, a reaction time of 45 min, and an operating temperature of 100 °C yielded the best visible light activity. The biosynthesized and chemically-synthesized Ag/TiO2 were compared using UV-Vis spectroscopy, X-ray fluorescence spectroscopy (XRF), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy-scanning electron microscopy (EDS-SEM) and transmission electron microscopy (TEM). Synthesis using WMRE yielded spherical Ag nanoparticles modified on the surface of TiO2 nanoparticles. The Ag nanoparticles had enhanced monodispersity with an average diameter of 7.48 ± 4.06 nm. Therefore, the developed WMRE green synthesis method provides a simple, less chemical-intensive, and effective alternative to chemical synthesis.

Novel nickel-immobilized-SiO2-TiO2 fine particles in the presence of cetyltrimethylammonium bromide as a catalyst for ultrasound-assisted-Kumada cross-coupling reaction.

Kumada cross-coupling reaction is useful for producing biphenyls, where nickel and copper have been widely investigated as catalysts but mainly homogeneous ones. In this study, we investigated ultrasound-assisted-Kumada cross-coupling reaction over the heterogeneous catalysts in which Ni2+, Cu2+, or both was immobilized on aminopropylsilane-functionalized-SiO2-TiO2 prepared in the presence of cetyltrimethylammonium bromide (CTAB). The presence of CTAB effectively prevented the particle growth and therefore SiO2-TiO2 fine particles with high surface area (502 m2 g-1) were formed. The Ni2+-immobilized catalyst showed high catalytic activity for the ultrasound-assisted-Kumada cross-coupling reaction of a wide variety of substrates and was reusable three times. Performing the reaction under ultrasound irradiation was very effective in significantly accelerating the reaction rate compared with the conventional mechanical method. In contrast to Ni2+, Cu2+ was deposited on the support as crystalline Cu(OH)2 and the resulting catalysts with Cu2+ and Ni2+-Cu2+ were less active and less stable under the reaction conditions.

The Electrocatalytic Role of Oxygen Vacancy in Nitrate Reduction Reactions.

Ammonia, with high energy density and easy transportation, holds significant potential to become an integral part of future energy systems. Among tremendous strategies, electrocatalytic ammonia production is no doubt an efficient and eco-friendly method. One particularly intriguing class of electrocatalysts for reducing nitrate to ammonia is transition metal oxides, which have been heavily researched. However, how these catalysts' oxygen vacancy (VO) affects their performance remains elusive. To address this, taking titania (the most important catalyst) as an example, we carried out experimental investigations and simulations. Contrary to the prevailing belief that the concentrated VO would increase the catalytic efficiency of nitrate reduction, it was found that a relatively low level of VO is favorable for maximizing catalytic efficiency. At low cathodic voltages, titania with minimal VO delivered both the highest reduction efficiency and the best selectivity among the different titania samples in this paper. In addition to outlining the merits of lower electron transfer resistance and accelerated reaction dynamics, we also put forth a previously unmentioned factor, the adsorption of hydrogen or the creation of an ordered hydrogen bond network, which put up a hydrogen-rich atmosphere for following nitrate reduction. Further simulation study revealed that within the hydrogen-rich atmosphere isolated VO serves as the ideal active center to enable the lowest energy barriers for the reduction of nitrate into ammonia. These findings offer fresh insights into the working mechanism of oxide-based electrocatalysts for ammonia production.

Anticorrosion Performance of Waterborne Coatings with Modified Nanoscale Titania under Subtropical Maritime Climate.

Steel structures located in subtropical marine climates face harsh conditions such as strong sunlight and heavy rain, and they are extremely corroded. In this study, a waterborne coating with excellent corrosion resistance, hydrophobic ability, high-temperature resistance and high density was successfully prepared by using modified nanoscale titania powders and grafted polymers. The effects of three modifiers on titania nanoparticles and waterborne coatings' properties were studied independently. The experimental results showed that the activation index of the modification employing methacryloxy silane reached 97.5%, which achieved the best modification effect at 64.4 °C for 43.3 min. The waterborne coating with nanoscale titania modified by methacryloxy silane exhibited the best hydrophobic effect, with a drop contact angle of 115.4° and excellent heat resistance of up to 317.2 °C. The application of the waterborne modified coating in steel structures under subtropical maritime climates showed that the waterborne titania coatings demonstrated excellent resistance to corrosion, high temperatures and harsh sunlight, with a maximum service life of up to five years. Economic analysis indicated that, considering a conservative three-year effective lifespan, this coating could save more than 50% in cost compared with conventional industrial coatings. Finally, the strengthening mechanism of the polymer coatings with modified nanoscale titania was analyzed.

Development and life cycle assessment (LCA) of super-oleophobic (under water) and super-hydrophilic (in-air) mesh membrane for oily water treatment.

This paper reports the fabrication, characterization, and environmental impact analysis of a super-oleophobic (under water) and super-hydrophilic mesh membrane for oily water treatment. In order to prepare mesh membrane, Titania nanoparticles (NPs) were spray coated on mesh stainless steel followed by calcination at 500 °C. After that, the Titania-coated mesh membrane was characterized using contact angle goniometry (CA), XRD, FE-SEM, EDX and elemental mapping. The FE-SEM, EDX, elemental mapping and XRD results confirmed that the Titania NPs were successfully coated on the surface of mesh membrane. CA results demonstrated that the prepared mesh membrane is super-hydrophilic and super-oleo phobic under water conditions, making it suitable for oil/water separation. Subsequently, life cycle assessment (LCA) was performed to determine the environmental impacts of Titania NPs-coated mesh membrane fabrication process. LCA results indicate that electricity and nitrogen contributed the most toward the eighteen environmental impact categories considered for this study.

Black Titanium Oxide/Activated TaS2 Flakes Photoelectrode for Plasmon Assisted Hydrogen Evolution at Neutral pH at High Current Density.

A heterojunction photo-electrode(s) consisting of porous black titanium oxide (bTiO2) and electrochemically self-activated TaS2 flakes is proposed and utilized for hydrogen evolution reaction (HER). The self-activated TaS2 flakes provide abundant catalytic sites for HER and the porous bTiO2, prepared by electrochemical anodization and subsequent reduction serves as an efficient light absorber, providing electrons for HER. Additionally, Au nanostructures are introduced between bTiO2 and TaS2 to facilitate the charge transfer and plasmon-triggering ability of the structure created. After structure optimization, high HER catalytic activity at acidic pH and excellent HER activity at neutral pH are achieved at high current densities. In particular, with the utilization of bTiO2@TaS2 photoelectrode (neutral electrolyte, sunlight illumination) current densities of 250 and 500 mA cm-2 are achieved at overpotentials of 433, and 689 mV, respectively, both exceeding the "benchmark" Pt. The addition of gold nanostructures further reduces the overpotential to 360 and 543 mV at 250 and 500 mA cm-2, respectively. The stability of the prepared electrodes is investigated and found to be satisfying within 24 h of performance at high current densities. The proposed system offers an excellent potential alternative to Pt for the development of green hydrogen production on an industrial scale.

Chlorin e6-Conjugated Mesoporous Titania Nanorods as Potential Nanoplatform for Photo-Chemotherapy.

Photodynamic therapy (PDT) has developed as an efficient strategy for cancer treatment. PDT involves the production of reactive oxygen species (ROS) by light irradiation after activating a photosensitizer (PS) in the presence of O2. PS-coupled nanomaterials offer additional advantages, as they can merge the effects of PDT with conventional enabling-combined photo-chemotherapeutics effects. In this work, mesoporous titania nanorods were surface-immobilized with Chlorin e6 (Ce6) conjugated through 3-(aminopropyl)-trimethoxysilane as a coupling agent. The mesoporous nanorods act as nano vehicles for doxorubicin delivery, and the Ce6 provides a visible light-responsive production of ROS to induce PDT. The nanomaterials were characterized by XRD, DRS, FTIR, TGA, N2 adsorption-desorption isotherms at 77 K, and TEM. The obtained materials were tested for their singlet oxygen and hydroxyl radical generation capacity using fluorescence assays. In vitro cell viability experiments with HeLa cells showed that the prepared materials are not cytotoxic in the dark, and that they exhibit photodynamic activity when irradiated with LED light (150 W m-2). Drug-loading experiments with doxorubicin (DOX) as a model chemotherapeutic drug showed that the nanostructures efficiently encapsulated DOX. The DOX-nanomaterial formulations show chemo-cytotoxic effects on Hela cells. Combined photo-chemotoxicity experiments show enhanced effects on HeLa cell viability, indicating that the conjugated nanorods are promising for use in combined therapy driven by LED light irradiation.

Unravelling the effects of nano SiO2, nano TiO2 and their nanocomposites on Zea mays L. growth and soil health.

Amidst the challenges posed by climate change, exploring advanced technologies like nanotechnology is crucial for enhancing agricultural productivity and food security. Consequently, this study investigated the impact of nano SiO2 (nSiO2), nano TiO2 (nTiO2) and SiO2/TiO2 nanocomposites (NCs) on 30-day-old Zea mays L. plants and soil health at concentrations of 100 and 200 ppm. Results showed that nSiO2 and nTiO2 at 100 ppm and SiO2/TiO2 NCs at both concentrations, positively influenced plant growth, with the best stimulation observed at 200 ppm of SiO2/TiO2 NCs. Improved plant growth was associated with higher chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance, rhizospheric N-fixing and phosphate solubilizing bacterial population and plant nutrient uptake. Additionally, treated plants exhibited increased cellulose and starch levels. Malondialdehyde (MDA) content was lower or similar to that of the control, except at 200 ppm of nTiO2-treated shoots. Antioxidant enzyme activities fluctuated, indicating physiological adjustments. Overall, 100 ppm of nTiO2 as well as nSiO2 and 100 and 200 ppm of SiO2/TiO2 NCs improved soil fertility and Z. mays growth, suggesting potential benefits for sustainable agriculture. The findings lay the foundation for more comprehensive investigations into the long-term fate of nanomaterials in soil and their intricate molecular-level interactions with Z. mays.

Robust Photocatalytic MICROSCAFS® with Interconnected Macropores for Sustainable Solar-Driven Water Purification.

Advanced oxidation processes, including photocatalysis, have been proven effective at organic dye degradation. Tailored porous materials with regulated pore size, shape, and morphology offer a sustainable solution to the water pollution problem by acting as support materials to grafted photocatalytic nanoparticles (NPs). This research investigated the influence of pore and particle sizes of photocatalytic MICROSCAFS® on the degradation of methyl orange (MO) in aqueous solution (10 mg/L). Photocatalytic MICROSCAFS® are made of binder-less supported P25 TiO2 NPs within MICROSCAFS®, which are silica-titania microspheres with a controlled size and interconnected macroporosity, synthesized by an adapted sol-gel method that involves a polymerization-induced phase separation process. Photocatalytic experiments were performed both in batch and flow reactors, with this latter one targeting a proof of concept for continuous transformation processes and real-life conditions. Photocatalytic degradation of 87% in 2 h (batch) was achieved, using a calibrated solar light simulator (1 sun) and a photocatalyst/pollutant mass ratio of 23. This study introduces a novel flow kinetic model which provides the modeling and simulation of the photocatalytic MICROSCAFS® performance. A scavenger study was performed, enabling an in-depth mechanistic understanding. Finally, the transformation products resulting from the MO photocatalytic degradation were elucidated by high-resolution mass spectrometry experiments and subjected to an in silico toxicity assessment.

Role of Atomicity and Interface on InOx-TiO2 Composites: Thermo-Photo Valorization of CO2.

The synthesis, physicochemical, and functional properties of composite solids resulting from the surface spread of oxidized indium species onto nanoplatelets of anatase were investigated. Both the size and the interaction between the indium- and titanium-containing components control the functional properties. In the reduction of CO2 to CO, the best samples have an indium content between ca. 2 and 5 mol % and showed an excess rate over the photo and thermo-alone processes above 33% and an energy efficiency of 1.3%. Subnanometric (monomeric and dimeric) indium species present relatively weak thermal catalytic response but strong thermo-photo promotion of the activity. A gradual change in functional properties was observed with the growth of the indium content of the solids, leading to a progressive increase of thermal activity but lower thermo-photo promotion. The study provides a well-defined structure-activity relationship rationalizing the dual thermo-photo properties of the catalysts and establishes a guide for the development of highly active and stable composite solids for the elimination and valorization of CO2.

Size-Dependent Effect of Titania Nanotubes on Endoplasmic Reticulum Stress to Re-establish Diabetic Macrophages Homeostasis.

In patients with diabetes, endoplasmic reticulum stress (ERS) is a crucial disrupting factor of macrophage homeostasis surrounding implants, which remains an obstacle to oral implantation success. Notably, the ERS might be modulated by the implant surface morphology. Titania nanotubes (TNTs) may enhance diabetic osseointegration. However, a consensus has not been achieved regarding the tube-size-dependent effect and the underlying mechanism of TNTs on diabetic macrophage ERS. We manufactured TNTs with small (30 nm) and large diameters (100 nm). Next, we assessed how the different titanium surfaces affected diabetic macrophages and regulated ERS and Ca2+ homeostasis. TNTs alleviated the inflammatory response, oxidative stress, and ERS in diabetic macrophages. Furthermore, TNT30 was superior to TNT100. Inhibiting ERS abolished the positive effect of TNT30. Mechanistically, topography-induced extracellular Ca2+ influx might mitigate excessive ERS in macrophages by alleviating ER Ca2+ depletion and IP3R activation. Furthermore, TNT30 attenuated the peri-implant inflammatory response and promoted osseointegration in diabetic rats. TNTs with small nanodiameters attenuated ERS and re-established diabetic macrophage hemostasis by inhibiting IP3R-induced ER Ca2+ depletion.

A unified framework of response surface methodology and coalescing of Firefly with random forest algorithm for enhancing nano-phytoremediation efficiency of chromium via in vitro regenerated aquatic macrophyte coontail (Ceratophyllum demersum L.).

Nano-phytoremediation is a novel green technique to remove toxic pollutants from the environment. In vitro regenerated Ceratophyllum demersum (L.) plants were exposed to different concentrations of chromium (Cr) and exposure times in the presence of titania nanoparticles (TiO2NPs). Response surface methodology was used for multiple statistical analyses like regression analysis and optimizing plots. The supplementation of NPs significantly impacted Cr in water and Cr removal (%), whereas NP × exposure time (T) statistically regulated all output parameters. The Firefly metaheuristic algorithm and the random forest (Firefly-RF) machine learning algorithms were coalesced to optimize hyperparameters, aiming to achieve the highest level of accuracy in predicted models. The R2 scores were recorded as 0.956 for Cr in water, 0.987 for Cr in the plant, 0.992 for bioconcentration factor (BCF), and 0.957 for Cr removal through the Firefly-RF model. The findings illustrated superior prediction performance from the random forest models when compared to the response surface methodology. The conclusion is drawn that metal-based nanoparticles (NPs) can effectively be utilized for nano-phytoremediation of heavy metals. This study has uncovered a promising outlook for the utilization of nanoparticles in nano-phytoremediation. This study is expected to pave the way for future research on the topic, facilitating further exploration of various nanoparticles and a thorough evaluation of their potential in aquatic ecosystems.

Investigation of Doehlert matrix conception in novel intrinsically conducting polymers based on selenium nanoparticles for wastewater treatment: Synthesis, characterization, kinetic and chemometric study.

The synthesis of robust intrinsically conducting polymers (ICPs) based on nanoparticles is becoming increasingly attractive to the research community due to the unique properties of these nanocomposites. Indeed, as organic semiconductors, ICPs combine both polymer and metal properties in a single structure. This study presents an innovative approach in which the Doehlert Matrix (DM) is applied to a novel ICP nanocomposite based on polyaniline (Pani) coupled with selenium (Se) loaded mesoporous titania (TiO2) for wastewater treatment by photocatalysis. It includes both the elaboration routes of ICP nanocomposites, characterization of materials by X-ray diffraction (XRD), BET analysis, thermogravimetric analysis (TGA), RAMAN spectroscopy and Fourier transform infrared spectroscopy (FTIR) and photodegradation of methylene blue (MB) as a representative of dye pollutant. In addition, the photocatalytic process has been optimized by a novel DM conception. The effect of the pH of the solution, the catalyst dosage and the initial pollutant concentration was investigated. The optimum conditions were found to be: initial MB concentration of 15 mg/L, the catalyst dosage of 69 mg and pH of 9.6 with an operating time of 75 min, with a coefficient of determination R2 equal to 0.9985. The removal efficiency of BM was close to 97 %. The study shows that the new ICP nanocomposites improve the photocatalytic efficiency compared to pure titania and/or pure Pani. In addition, as the ternary Pani-Se-TiO2 nanocomposite could be obtained from a low-cost synthesis, it is a very promising material for use in wastewater treatment.

Oxide-Encapsulated Silver Electrocatalysts for Selective and Stable Syngas Production from Reactive Carbon Capture Solutions.

Electrolysis of bicarbonate-containing CO2 capture solutions is a promising approach towards achieving low-cost carbon-neutral chemicals production. However, the parasitic bicarbonate-mediated hydrogen evolution reaction (HER) and electrode instability in the presence of trace impurities remain major obstacles to overcome. This work demonstrates that the combined use of titanium dioxide (TiO2) overlayers with the chelating agent ethylene diamine tetra-acetic acid (EDTA) significantly enhances the selectivity and stability of Ag-based electrocatalysts for bicarbonate electrolysis. The amorphous TiO2 overlayers suppress the HER by over 50 % at potentials more negative than -0.7 V vs. RHE, increasing the CO faradaic efficiency (FE) by 33 % (relative). In situ surface-enhanced Raman spectroscopy (SERS) measurements reveal the absence of near-surface bicarbonate species and an abundance of CO2 reduction intermediates at the Ag|TiO2 buried interface, suggesting that the overlayers suppress HER by blocking bicarbonate ions from reaching the buried active sites. In accelerated degradation tests with 5 ppm of Fe(III) impurity, the addition of EDTA allows stable CO production with >47 % FE, while the electrodes rapidly deactivate in the absence of EDTA. This work highlights the use of TiO2 overlayers for enhancing the CO : H2 ratio while simultaneously protecting electrocatalysts from impurities likely to be present in "open" carbon capture systems.

Effective impact of nano-plastic-waste incorporated with nanotitina on the physical, mechanical and microstructural properties of white cement pastes composites for progressing towards sustainability.

Plastic waste (PW) has received a lot of attention as a possible additional material for industrial and environmental applications, particularly cement and/or concrete production for a more environmentally and economically sound use of raw materials and energy sources. PW has been investigated as an inert and/or active hydraulic filler for cement and/or concrete by numerous scientists. Plastic garbage is cheap, abundant, and takes long period of time to degrade in the eco-system (soil and water). The main goal of the ongoing research is to offer safety and efficacy by partially substituting nano-plastic waste (NPW), incorporated with nano-titania (NT), for the composition of white cement (WC). Blends are built up by substitution of WC with different ratios of NPW incorporated with fixed ratios of nano-titania (1.0 wt.%). Workability, physical, mechanical and microstructural properties have gone through laboratory and instrumental analysis. The results showed improvement in the compressive strength, density and microstructure due to the effective impact of fillers. Consequently, a decrease in total porosity, whiteness reflection (Ry) and early-rapid expansion. Eventually, the outcomes may reduce the pandemic strength, especially in the external environment, and other epidemics.

Copper-Decorated Titanium Electrodes: Impact of Surface Modifications of Substrate on the Morphology and Electrochemical Performance.

This study investigates the effect of surface modifications of the titanium substrate on the growth of electrochemically deposited copper. These materials are intended to serve as cathodes in the electroreduction of nitrates in aqueous solutions. Surface modifications included the use of hydrogen fluoride for titanium etching and anodization to promote the growth of a structured titania nanotube array. The effect of an intermediate calcination step for the nanotubes before deposition was assessed along with a comparison to an untreated substrate electrode. The materials were comprehensively characterized by SEM, XRD, contact angle, potentiodynamic tests, EIS, and cyclic voltammetry. Their electrocatalytic ability was tested in the reduction of aqueous solutions containing nitrates. The results reveal that surface finishing impacted the shape and size of the Cu microparticles, as well as the nucleation mechanism enabling a crystal-facet-controllable synthesis. All the materials exhibited microsized copper particles with a spherical shape with some clusters. On the etched titanium surface, a high number of heterogeneous submicroscopic particles were also present. The thermally treated anodized substrate promoted the development of a combination of sparse microparticles corresponding to defect sites in amorphous titanium and the presence of a diffuse coating of octahedral nanosized particles whose growth was promoted by the tetragonal structure of anatase crystals. Electrochemical tests display reduced charge transfer resistance upon copper deposition on the modified substrates, which is indicative of the enhanced conductivity of the coated materials. Additionally, cyclic voltammetry and electrolysis experiments reveal the electrodes' potential for nitrate reduction, showing a better response for the etched titanium substrate (30% nitrate removal, after 2 h at 25 mA cm-2).