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The photochemical degradation of natural rubber (NR) is a prevalent method used to modify its inherent properties. Natural rubber, predominantly derived from the Hevea Brasiliensis tree, exhibits an exceptionally high molecular weight (MW), often reaching a million daltons (Da). This high MW restricts its solubility in various solvents and its reactivity with polar compounds, thereby constraining its versatile applications. In our previous work, we employed TiO2 in its powdered form as a photocatalyst for the functionalization of NR latex. However, the post-process separation and reuse of this powder present substantial challenges. In this present study, we aimed to functionalize deproteinized NR (DPNR) latex. We systematically reduced its MW via photochemical degradation under UVA irradiation facilitated by H2O2. To enhance the efficiency of the degradation process, we introduced TiO2-coated hollow glass beads (TiO2-HGBs) as photocatalysts. This approach offers the advantage of easy collection and repeated reuse. The modified DPNR showed a reduction in its number-average MW from 9.48 × 105 to 0.28 × 105 Da and incorporated functional groups, including hydroxyl, carbonyl, and epoxide. Remarkably, the TiO2-HGBs maintained their performance over seven cycles of reuse. Due to their superior efficacy, TiO2-HGBs stand out as promising photocatalysts for the advanced functionalization of NR across various practical applications. [ABSTRACT FROM AUTHOR]

Visible-light active La-Fe-SrTiO3 (La0.01Sr0.99Fe0.01Ti0.99O3) photocatalysts were synthesized via a dynamic hydrothermal route under different NaOH concentrations (2, 3, 4, 5, and 6 M). The results showed that altering NaOH concentrations changed the physicochemical characteristics of the materials. Namely, the decrease in particle size was observed when the NaOH levels were increased. The specific surface area of the photocatalysts changed with an increased concentration of NaOH, and the maximum value was 17.10 m2/g in 5 M of NaOH. The crystal structure of all prepared samples remained unaffected when altered the NaOH concentration or when incorporated La and Fe in the lattice of SrTiO3. Namely, all samples synthesized under various NaOH concentrations crystallized and maintained in the standard cubic perovskite structure of SrTiO3. The increased NaOH concentration slightly altered the absorption wavelength towards a longer wavelength region. The La atom, replacing some Sr2+ in the structure of modified SrTiO3, was confirmed to be in the La3+ valence state. Simultaneously, Fe atoms demonstrating oxidation states of Fe3+ can also be incorporated into the SrTiO3 network. The photocatalytic degradation of ciprofloxacin antibiotic revealed that the highest performance was approximately 75% within 9 h over the La0.01Sr0.99Fe0.01Ti0.99O3 sample prepared at 5 M of NaOH via the dynamic hydrothermal process. Meanwhile, this photocatalyst also displayed greater activity than the pristine SrTiO3, the single-doped samples (SrFe0.01Ti0.99O3 and La0.01Sr0.99TiO3), and the La0.01Sr0.99Fe0.01Ti0.99O3 sample prepared through a static hydrothermal technique under the same synthesis condition. [ABSTRACT FROM AUTHOR]

The degradation of formaldehyde in a photo-Fenton reaction was studied using n-ZVI/TiO2 as the catalyst. The effects of %n-ZVI loading, catalyst dosage, H2O2, and pH on formaldehyde degradation were studied. The n-ZVI/TiO2 catalysts were prepared by impregnation with chemical reduction, and their catalytic activity was evaluated in a batch reactor under UVC light. Transmission electron microscopy (TEM) was used to determine that the n-ZVI nanoparticle size was 39.41 nm. X-ray photoelectron spectroscopy (XPS) was used to study the oxidation states of 2%n‑ZVI/TiO2, and the Fe 2p spectrum of 2%n-ZVI/TiO2 indicated the presence of Fe0. The optimal conditions for the complete removal of formaldehyde within 30 min were an n-ZVI loading of 2 wt.%, a catalyst dosage of 0.5 g/L, 30 mM H2O2, and an initial pH of 3. After the reaction, the C–H functional group of formaldehyde was not observed due to the •OH radicals generated by Fe0 and H2O2 attacking the formaldehyde molecule. Moreover, no Fe leaching was observed, presenting an advantage compared with homogeneous Fe catalysts. Therefore, 2%n‑ZVI/TiO2 shows excellent potential as a photo-Fenton catalyst for the environmentally friendly degradation of formaldehyde. [ABSTRACT FROM AUTHOR]

This work focuses on the variation of solvents/additives as a key factor in hydrothermal and solvothermal syntheses of nanocrystal BiVO4 films. All synthesized films successfully formed the BiVO4 monoclinic phase, which was confirmed by XRD, XPS, XANES and EDS techniques. The physico-chemical characteristics of these solvents/additives have dramatic impacts on the crystal morphologies and surface crystal planes. Using ethanol and ethylene glycol gives plate-like BiVO4 with {121} as a dominant facet. On the other hand, preparations with low pH and higher polar solvents result in {010}-dominated nanocrystals. The effects of the three solvent molecules including water, methanol, and ethanol are investigated by computations. Interestingly, the adsorption energy of each solvent molecule on various facets is different, leading to diverse exposure of the lattice planes. Overall, the photoanodes with plate-like particles give better catalytic activities. These films have higher-index {121} exposed facets, more oxidative (110) plane and better charge transfer properties. The photoelectrochemical photocurrent switching effects are also observed with varied switching potentials, suggesting that the (110) and (040) planes are the controlling parameters. The obtained knowledge from this work may be useful for the fabrication of photoelectrodes with expanded fields of application. [ABSTRACT FROM AUTHOR]

Zeolites in powder form have the potential to agglomerate, lowering access to active sites. Furthermore, a suspension of fine zeolite powder in liquid media is difficult to separate. Such drawbacks could be improved by dispersing zeolite crystals on support materials. This work demonstrates the dispersion of zeolite NaY crystals on bamboo wood by mixing the wood with zeolite gel before hydrothermal treatment. The syntheses were performed with acid-refluxed and non–refluxed wood. The phase of zeolites, particle distribution and morphology, zeolite content in the wood, and zeolite–wood interaction were investigated using X-ray diffraction, X-ray tomography, scanning electron microscopy, thermogravimetric analysis, nitrogen sorption analysis, and X-ray photoelectron spectroscopy. Higher zeolite content and better particle dispersion were obtained in the synthesis with the acid–refluxed wood. The composite of NaY on the acid-refluxed wood was demonstrated to be an effective adsorbent for Ni(II) ions in aqueous solutions, providing a higher adsorbed amount of Ni(II) per weight of NaY. [ABSTRACT FROM AUTHOR]

A novel tungsten disulfide-molybdenum copper oxide composite supported with graphene quantum dots (WM@GQDs) has been synthesized as a counter electrode (CE) for dye-sensitized solar cells (DSSCs) using a simple and low-cost ultrasonication method. The unique structure of WM@GQDs exhibits excellent power conversion efficiency due to its high catalytic activity and charge transport properties. In addition, the graphene quantum dots (GQDs) provide more active sites in the zero-dimensional materials for an I/I3− redox reaction which can improve the electrical and optical properties of the composite. The results indicate that the amount of GQDs in the composite affect the effectiveness of solar devices. When 0.9%wt of GQDs was used, the WM@GQDs composite achieved an efficiency of 10.38%, which is higher than that of the expensive platinum CE under the same conditions. The mechanism behind the improved power conversion efficiency (PCE) of the composite sample is also discussed in detail. Therefore, WM@GQDs can be an efficient material to replace platinum in DSSCs as a CE. [ABSTRACT FROM AUTHOR]

Macca carbon (MC), derived from high-temperature carbonized macadamia nut-in-shell wastes from macadamia nut processing, exhibits a high surface area, high number of electrons, and high efficiency in emitting far-infrared (FIR) radiation at wavelengths between 4 and 20 μm. Numerous inventions have demonstrated promising results in health improvement applications, such as increased blood circulation, less inflammation, and enhanced life expectancy. In this study, MC and a pressure-sensitive adhesive (PSA) were coupled to form a new bandage called an MC cohesive bandage. It was manufactured by combining various quantities of MC powder with PSA and applying it to a spandex fabric tape. The peeling test, water permeability, and skin irritation were examined. The quantity of FIR radiation between 6 and 14 μm and the thermal properties of MC cohesive bandages were investigated. The FIR penetration effectiveness was determined by measuring the temperature rises from the streaky pig skin covered with MC cohesive bandages at various depths. [ABSTRACT FROM AUTHOR]

Coating of photocatalytic nanomaterials on various surfaces enables interesting applications. This work demonstrates the ability of the aerosol-assisted chemical vapor deposition (AACVD) approach to prepare high-quality BiOCl nanostructure-based films and also to tune the nanostructure and photocatalytic properties of the films by varying the solvent and carrier gas. Solvents have a dramatic impact on the surface morphologies and crystallite size. X-ray diffraction (XRD) and grazing incidence X-ray diffraction (GIXRD) analyses indicate that BiOCl crystals displayed preferential growth in the (101) plane in most samples, while both the (101) and (102) planes were favored in films deposited using ethyl acetate and methanol. Surface energy and adsorption energy calculation reveal that the preferred growth depends on the interaction between the Bi atom and solvent molecules. X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDS) characterizations showed that all films did not contain any impurity elements but did contain some oxygen vacancies. The obtained nanostructured BiOCl films show good photocatalytic properties. The highest photocatalytic NOx removal efficiency is achieved in the film prepared using ethyl acetate and air, which we attribute to the large crystallite size and therefore high mobility of the carriers. Herein, we show that different crystal morphologies and sizes of BiOCl have strong impacts on the photocatalytic activity toward NO oxidation, and both factors can be effectively tuned in the AACVD process. Such knowledge may be useful for future research on coating materials for resolving environmental problems. [ABSTRACT FROM AUTHOR]

Turning waste glycerol into a fundamental chemical used in the petrochemical industry offers an opportunity to reduce not only waste from biodiesel production but also the consumption of petroleum-based chemicals. In the present work, glycerol was converted to 1,3-propanediol over Pt-WOx/Al2O3 catalysts, while focusing on the influence of W loading contents (10–20 wt.%) and catalyst pretreatment conditions, specifically the calcination temperatures of WOx/Al2O3 (700–900 °C), calcination temperatures of Pt-WOx/Al2O3 (350–450 °C) and reduction temperatures of Pt-WOx/Al2O3 (300–400 °C). The characteristics of the catalysts were identified by applying N2-sorption, XRD, Raman, CO pulse chemisorption, NH3-TPD, H2-TPR, H2-TPD, SEM and TEM-EDS and XPS. The W loading contents and pretreatment conditions strongly affected the activity and products selectivity. The W content and calcination temperature of WOx/Al2O3 at 15 wt.% and 800 °C, respectively, were evaluated as the most suitable in providing optimum W-O-W clusters to generate Hδ+ which was a key parameter for the generation of 1,3-propanediol. The calcination and reduction temperatures of Pt-WOx/Al2O3 at 400 °C and 350 °C, respectively, were mandatory to sufficiently convert PtCl2 to Pt3O4 and Pt3O4 to metallic Pt, respectively. The optimized Pt-WOx/Al2O3 catalyst achieved a high glycerol conversion (44.7%) with high selectivity toward 1,3-propanediol (45.1%) under a reaction temperature and pressure of 220 °C and 60 bar, respectively. [ABSTRACT FROM AUTHOR]

Novel MoWO4 with ZnO nanoflowers was synthesized on multi-walled carbon nanotubes (MW-Z@MWCNTs) through a simple hydrothermal method, and this unique structure was applied as a counter electrode (CE) for dye-sensitized solar cells (DSSC) for the first time. The synergetic effect of ZnO nanoflowers and MoWO4 on MWCNTs was systematically investigated by different techniques. The amount of MWCNTs was optimized to achieve the best DSSC performance. It was found that the 1.5% MW-Z@MWCNTs composite structure had the highest power conversion efficiency of 9.96%, which is greater than that of traditional Pt CE. Therefore, MW-Z@MWCNTs-based CE can be used to replace traditional Pt-based electrodes in the future. [ABSTRACT FROM AUTHOR]

The corrosion resistance of materials composed of metal is an essential property for preventing material deterioration caused by corrosion. In this study, we demonstrate that corrosion resistance can be significantly improved through the electrodeposition of molybdenum oxide onto a metal plating containing iron-group elements. Mo oxide can be electrodeposited using a simple plating bath, low current density, and short deposition time, exhibiting a fascinating metallic gloss appearance. GI-XRD and XPS analyses revealed that amorphous Mo oxide adhered to the substrate by a seed layer partially reduced to metallic Mo by the iron-group element in the substrate, based on the principle of “induced co-deposition.” A Mo oxide coating with a thickness of approximately 100 nm decreases the corrosion current density of Ni-W plating by approximately 5 times and the passivation current density by approximately 10 times in a 3 mass% NaCl solution. Mo oxide coatings represent an attractive strategy for improving the corrosion resistance of various metal materials containing iron-group elements. [ABSTRACT FROM AUTHOR]

[Display omitted] • Converting agricultural waste to an adsorbent for herbicide removal from water. • Use of rice husk ash-SiO 2 in dry-gel conversion to prepare magnetic BEA zeolite. • Adsorbent for paraquat removal with at least 4-cycle reusability is obtained. • Fe 3 O 4 addition allows magnetic collection while maintaining adsorption reusability. This study presents a method that will allow for the sustainable utilization of rice husk ash-SiO 2 (RHAS), an agricultural-waste – derived material, as a bulky solid SiO 2 source in the zeolite beta (BEA)/Fe 3 O 4 composite (magnetic RHAS-BEA) synthesis via a dry-gel conversion method for the removal of paraquat, a typical herbicide, from aqueous solutions. Ultrasonic waves were used to facilitate the formation of uniform Fe 3 O 4 -contained dry precursor gel before converting to the magnetic BEA zeolite composite for the first time. Magnetic RHAS-BEA was then characterized and compared with a non-magnetic sample (RHAS-BEA) using X-ray diffraction and field-emission scanning electron microscopy. In terms of adsorption, we found that paraquat had a high adsorption rate on the samples and conformed to a pseudo-second-order kinetic model. The adsorption behavior of paraquat on the synthesized RHAS-BEA and magnetic RHAS-BEA obeyed the Langmuir adsorption isotherm model. The synthesized adsorbents were reusable for at least four cycles, via thermal regeneration at 450 °C. The inclusion of Fe 3 O 4 particles in magnetic RHAS-BEA disrupted neither the crystallization of the BEA zeolite nor the adsorption of paraquat and enabled easy collection via an external magnet. [ABSTRACT FROM AUTHOR]

ABSTRACT Electrospun fibers for ferric ion (Fe3+) detection were prepared from solutions of poly(methyl methacrylate) (PMMA), poly(vinyl chloride- co-vinyl acetate- co-vinyl alcohol) ((90 : 4 : 6), PVC terpolymer), and pyrene. The effects of PVC terpolymer content (0, 10, 20, 30, and 40% by weight of PMMA) and electrospinning conditions on fiber size and morphology were studied using scanning electron microscopy. Uniform fibers were obtained from all compositions, and fiber sizes slightly increased with PVC terpolymer content. At 40% PVC, fiber breakage and pyrene clusters were observed. The suitable pyrene content in electrospun fibers was found to be 20%. The ratio of fluorescence intensities of fibers with 30% PVC and 20% pyrene before and after ( F0/ F) immersion in 1.0 m M Fe3+ solution was 1.36. The effect of Fe3+ concentrations (0-5.0 m M) on quenching ability was investigated. An excellent Stern-Volmer quenching relationship was found with KSV of 2.26 × 102 M. Fibrous sensor exhibited a highly sensitive response toward Fe3+ over Cu2+, Mg2+, Co2+, Zn2+, Ni2+, and Ag+. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3205-3211, 2013 [ABSTRACT FROM AUTHOR]