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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]

In this work, Y 2/3 Cu 3 Ti 4 O 12 ceramics were fabricated via a modified sol−gel route. Structural, dielectric, and electrical parameters were systematically investigated. The XRD results indicate that a CaCu 3 Ti 4 O 12 phase (JCPDS No. 75–2188) is present in every sintered sample. SEM images of Y 2/3 Cu 3 Ti 4 O 12 ceramics disclose a fine-grained ceramic microstructure. Interestingly, high dielectric permittivity, ∼6600–7600, with loss tangents of ∼0.918–1.086 were achieved in the sintered Y 2/3 Cu 3 Ti 4 O 12 samples. Density functional theory (DFT) calculations were used to investigate the most stable structure of the Y 2/3 Cu 3 Ti 4 O 12 ceramics. Our DFT results reveal that two calcium vacancies (V Ca) are isolated from each other. We also determined the lowest energy configuration of an oxygen vacancy (V O) in the Y 2/3 Cu 3 Ti 4 O 12 ceramics occurred during the sintering process. We found that the V O is trapped close to the Y atom in this structure. Both computational and experimental studies specify that the oxygen vacancy is located close to the Y atom in the Y 2/3 Cu 3 Ti 4 O 12 lattice and it might be a bivalent oxygen vacancy. As a result, due to charge balance, charge compensation of the transition ions, i.e. , Cu and Ti ions, might take place. The charge compensation mechanisms in the Y 2/3 Cu 3 Ti 4 O 12 lattice were verified using an XPS technique. Impedance spectroscopy confirms the presence of an inhomogeneous microstructure consisting of semiconducting grains and insulating grain boundaries in the sintered Y 2/3 Cu 3 Ti 4 O 12 ceramics. This electrical result is consistent with the computational analysis, showing that a charge compensation mechanism might be involved in generation of the grains' semiconductive region due to the presence of a V O. Consequently, high dielectric permittivity in Y 2/3 Cu 3 Ti 4 O 12 may have originated from an internal barrier layer capacitor (IBLC) effect. [ABSTRACT FROM AUTHOR]

[Display omitted] Sunlight active CdS/BiOBr heterojunction photocatalyst was fabricated by a solvothermal route. To the best of our knowledge, the novelty of the research is based on the decoration of the hexagonal CdS nanoparticles on the surface of the tetragonal BiOBr microflowers for the creation of a heterostructure photocatalyst used for the removal of the antibiotics. The CdS/BiOBr-1:3 heterojunction exhibited 100% removal of norfloxacin and ciprofloxacin under simulated visible light. In addition, complete degradation of the antibiotics under natural sunlight was also achieved. Construction of the CdS/BiOBr heterojunction is a promising strategy for the improvement of photocatalytic performance due to a decrease in the charge carrier recombination rate at the interface, an increase in the visible light absorption range, and an enhancement of the surface area of the resultant product. The removal of the pollutants fit very well with the first-order reaction. The photogenerated hole played a crucial role in the removal of the antibiotics. Confirmation of the stability of the CdS/BiOBr heterojunction was also elucidated. The photoactivity of the photocatalyst remained the same after the fifth cycle implying the excellent cycling ability of the sample. This research demonstrates the promising potential of the CdS/BiOBr heterojunction for degradation of toxic antibiotics presented in water. [ABSTRACT FROM AUTHOR]

Natural rubber (NR), a long-chain hydrocarbon polymer mostly consisting of cis-1,4-polyisoprene units, has a high molecular weight (MW) and viscosity, enabling it to show excellent physical properties. However, NR has no reactive functional group, making it difficult to react with other molecules, especially in manufacturing processes. The functionalized low-molecular-weight NR (FLNR) is a requirement to disperse ingredients into the rubber adequately. Here, the FLNR was prepared by a photochemical degradation process under UVC-irradiation in the presence of H2O2 using P25-titanium oxide (TiO2) powder as a photocatalyst. The optimum condition for the preparation of FLNR was the use of 2.0 g of TiO2 powder per 100 g of rubber and H2O2 at 20% w/w under UVC-irradiation for 5 h. The hydroxyl groups were found on the NR chains due to the chain-scission of polyisoprene chains and hydroxyl radicals in the system. The weight average MW of NR decreased from 12.6 × 105 to 0.6 × 105 gmol−1, while the number average MW decreased from 3.3 × 105 to 0.1 × 105 gmol−1. [ABSTRACT FROM AUTHOR]

In this work, chitosan-grafted-poly(acrylic acid) (CS-g-PAA) was synthesized for use as a Co2+ adsorbent and circularly utilized as a peroxymonosulfate (PMS) activator in the degradation of rhodamine B (RhB) dye. CS-g-PAA demonstrated 3.7 times higher adsorption capacity toward Co2+ than pristine chitosan. The impact of the adsorption conditions was evaluated. The pseudo-second-order kinetic model and the Langmuir isotherm model best described the adsorption process. Under optimum conditions, the adsorption capacity of CS-g-PAA for Co2+ was 212 mg/g. The Co2+-adsorbed CS-g-PAA hydrogel was further utilized in the RhB degradation process. The effects of catalyst dosage, initial RhB concentration, pH, and the coexistence of anions on the degradation of RhB were studied. The hydrogel catalyst could remove 98 % of RhB within 5 min, at a degradation rate of 0.624 per min. Electron paramagnetic resonance (EPR) analysis and the radical scavenger experiment suggested that SO 4 •−, HO•, 1O 2 , and O 2 •− were involved in the degradation. Furthermore, when tested in various water systems, high degradation efficiencies of 98 % were attained after 20 min. The hydrogel catalyst performed excellent degradation over ten cycles without any chemical recovery processes. Moreover, high degradation efficiencies were observed between 95 % and 98 % when tested with other dyes. [ABSTRACT FROM AUTHOR]

Chitosan-grafted-poly(acrylic acid) (CS-g-PAA) and chitosan-grafted- poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (CS-g-P(AA- co -AMPS)) hydrogels were synthesized and then employed as adsorbents for the effective removal of Cu2+ and other heavy metal ions. The effect of hydrogel's composition on the Cu2+ adsorption was explored. The CS-g-PAA hydrogel demonstrated a superior adsorption capacity compared to pristine CS, PAA hydrogel, and CS-g-P(AA-co-AMPS) hydrogels. The adsorption followed the Langmuir isotherm model, and the pseudo-second order kinetic model. Additionally, the CS-g-PAA hydrogel exhibited relatively high adsorption performances toward Cr3+, Co2+, Ni2+, Pb2+, and Zn2+. Metal ions adsorbed within CS-g-PAA hydrogels underwent reduction to their corresponding metallic states and were reutilized as catalysts for the reduction of 4-nitrophenol. The comparative catalytic performances of the metal species in the hydrogel were in the order of Cu > Ni > Co > Zn. The reduction efficiency of Cu-CS-g-PAA increased with increased catalyst dosage, NaBH 4 concentration, and temperature. A very low activation energy of 3.7 kJ/mol was observed. The catalyst maintained high catalytic performance even when subjected to real water samples and proved its reusability for up to three cycles. Moreover, the catalyst could effectively reduce 2-nitrophenol and methyl orange. [ABSTRACT FROM AUTHOR]

Chitosan-grafted-poly(acrylic acid) (CS-g-PAA) and chitosan-grafted- poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (CS-g-P(AA- co -AMPS)) hydrogels were synthesized and then employed as adsorbents for the effective removal of Cu2+ and other heavy metal ions. The effect of hydrogel's composition on the Cu2+ adsorption was explored. The CS-g-PAA hydrogel demonstrated a superior adsorption capacity compared to pristine CS, PAA hydrogel, and CS-g-P(AA-co-AMPS) hydrogels. The adsorption followed the Langmuir isotherm model, and the pseudo-second order kinetic model. Additionally, the CS-g-PAA hydrogel exhibited relatively high adsorption performances toward Cr3+, Co2+, Ni2+, Pb2+, and Zn2+. Metal ions adsorbed within CS-g-PAA hydrogels underwent reduction to their corresponding metallic states and were reutilized as catalysts for the reduction of 4-nitrophenol. The comparative catalytic performances of the metal species in the hydrogel were in the order of Cu > Ni > Co > Zn. The reduction efficiency of Cu-CS-g-PAA increased with increased catalyst dosage, NaBH 4 concentration, and temperature. A very low activation energy of 3.7 kJ/mol was observed. The catalyst maintained high catalytic performance even when subjected to real water samples and proved its reusability for up to three cycles. Moreover, the catalyst could effectively reduce 2-nitrophenol and methyl orange. [ABSTRACT FROM AUTHOR]

In this work, the principles of environmentally friendly and efficient resource utilization have been implemented to move towards achieving carbon neutrality. Accordingly, the confined-space molecular-sieve properties of ZSM-5 zeolite were applied in cooperation with an external magnetic field with the aim to improve the catalytic LPG conversion and the selectivity of BTX (benzene, toluene, and xylenes) over Fe-Ga/ZSM-5 zeolites (0.5 wt.% Ga and 0.1 wt.% Fe). Effect of ZSM-5 particle sizes (0.6 μm, 1.1 μm, and 22.1 μm) on BTX yields and toluene to monoaromatic hydrocarbons were examined under magnetic field at a flux intensity of 28.7 mT in North-to-South direction and compared to those without magnetic field. The highest LPG conversion over Fe-Ga/ZSM-5 catalyst was found at the ZSM-5 particle size of 1.1 µm under external magnetic field, which is 1.2 times greater than that without magnetic field. The BTX yield was also increased by factors of 1.5 compared to those without magnetic field. The outstanding performance can be attributed to the synergistic effects between the external magnetic field and limited mass transfer within the confined-space zeolite. This combination facilitates and enhances the mass transfer ability and reaction performance of the reactant molecules. Consequently, this synergistic effect can lead to the development of green and sustainable innovations for chemical and separation processes in the future. [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]

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]

• Simultaneously appearing CaTiO 3 and TiO 2 phases in CaCu 2.8 Ti 4 O 12 ceramics were prepared by a polymer pyrolysis route. • Mg2+ substitution at the Cu sites of Cu-deficient CaCu 2.8- x Mg x Ti 4 O 12 (x = 0–0.10) causes increased R gb values. • tanδ = 0.011, ε′ = 11,603 and ∆ε′ ≤ ± 15% (−60 to 180 °C) were attained for x = 0.05. • This ceramic has a potential applications in a high-temperature X8R capacitors. • The highest α = 53.02 with E b = 9548.1 V cm−1 was achieved. Mg2+ substitution at the Cu sites of Cu-deficient CaCu 2.8- x Mg x Ti 4 O 12 (x = 0.00, 0.05, and 0.10) ceramics was accomplished using a polymer pyrolysis technique. The nonlinear and dielectric properties of all ceramics under various sintering temperatures were investigated. Very low tanδ ∼ 0.011–0.030 and giant ε ′ ∼ 4406–13,521 were obtained in these ceramics. Surprisingly, excellent thermal stability, where ε ′ remained within± 15% and is adequate for X8R capacitors, is obtained in CaCu 2.75 Mg 0.05 Ti 4 O 12 and CaCu 2.7 Mg 0.1 Ti 4 O 12 ceramics sintered at 1100 °C for 8 h. Additionally, the nonlinear J-E properties were improved compared to an unmodified sample. Interestingly, a nonlinear coefficient (α) of ∼ 58.05 in the CaCu 2.75 Mg 0.05 Ti 4 O 12 ceramic sintered at 1100 °C for 8 h is acceptable for varistor applications. Improvement of nonlinear and dielectric properties arise from the electrical interface responses altered by Mg2+ substitution. The ceramics were characterized using XRD, TEM and FE-SEM techniques to investigate their crystal structure and microstructure. EDXS results confirmed the coexistence of TiO 2 and CaTiO 3 phases in all ceramics. It was suggested that the enhancement of grain boundary resistance (R gb) with simultaneously improved electrical and nonlinear J-E behaviors caused by the alternation of electrical interface responses at GBs. XPS measurements of these ceramics presented Cu3+/Cu2+/Cu+ ratios that indicate the semiconducting properties of grains. [ABSTRACT FROM AUTHOR]

[Display omitted] • K-O-Co species is created for K-Co promoted In 2 O 3. • The presence of K-O-Co species reduces a number of weak H 2 adsorption. • The formation of K-O-Co species inhibits the hydrogenation ability. • The best catalyst achieves a high C 2+ OH space time yield of 169.6 g kg cat −1h−1. • The best catalyst shows the excellent stability up to 200 h time-on-stream. The use of CO 2 to produce higher alcohols is a promising route to reduce emissions and make a profit. However, low activity of existing catalysts is a barrier for such processes to reach the industrial level. Here we report a novel K-Co promoted In 2 O 3 catalyst for CO 2 hydrogenation to higher alcohols. The K-Co promoted In 2 O 3 with an optimum K and Co of 2.5 and 5.0 wt% achieves a high C 2+ OH space time yield of 169.6 g kg cat −1h−1 with the excellent C 2+ OH distribution of 87.4% in the total alcohols, while a very low space time yield of C 2+ OH (0.4 g kg cat −1h−1) is obtained over In 2 O 3 promoted with 5 wt% Co. Characterization results reveal that, after reduction with H 2 at 380 °C for 2 h, K-O-Co species is created for K-Co promoted In 2 O 3 (2.5 wt% K and 5 wt% Co) sample which significantly reduces a number of weak H 2 adsorption and strengthens the interaction of adsorbed H compared to 5 wt% Co promoted In 2 O 3 sample containing a mixture of Co0 and CoO. The reduction of weak H 2 adsorption and the improved interaction of adsorbed H with the catalyst surface retard the hydrogenation ability, allowing the CO insertion into adsorbed C x H y species prior to its hydrogenation to form hydrocarbon, resulting in a remarkable reduction of CH 4 and higher hydrocarbon, and significant improvement of higher alcohols. [ABSTRACT FROM AUTHOR]

The remediation of water streams, polluted by various substances, is important for realizing a sustainable future. Magnetic adsorbents are promising materials for wastewater treatment. Although numerous techniques have been developed for the preparation of magnetic adsorbents, with effective adsorption performance, reviews that focus on the synthesis methods of magnetic adsorbents for wastewater treatment and their material structures have not been reported. In this review, advancements in the synthesis methods of magnetic adsorbents for the removal of substances from water streams has been comprehensively summarized and discussed. Generally, the synthesis methods are categorized into five groups, as follows: direct use of magnetic particles as adsorbents, attachment of pre-prepared adsorbents and pre-prepared magnetic particles, synthesis of magnetic particles on pre-prepared adsorbents, synthesis of adsorbents on preprepared magnetic particles, and co-synthesis of adsorbents and magnetic particles. The main improvements in the advanced methods involved making the conventional synthesis a less energy intensive, more efficient, and simpler process, while maintaining or increasing the adsorption performance. The key challenges, such as the enhancement of the adsorption performance of materials and the design of sophisticated material structures, are discussed as well. [ABSTRACT FROM AUTHOR]

[Display omitted] • A Ti-Al-C MAX phase (Ti 3 AlC 2) is used to recover gold from acidic solutions. • High gold extraction capacity (>6000 mg/g) is achieved at pH < 1. • High selectivity for gold is observed in the presence of interfering metal ions. • Gold recovery is likely to proceed via a reduction reaction similar to cementation. • High purity gold (92 mass%) is recovered without any posttreatment. Given the scarcity of natural gold sources and associated mining challenges, the recovery of gold from secondary sources, such as electronic equipment waste (e-waste), becomes imperative. E-waste is typically treated with aqua regia to obtain highly acidic gold-containing solutions, which are subsequently processed by various methods to recover gold. Gold recovery materials offer numerous benefits but often exhibit insufficient selectivity, efficiency, and cost-effectiveness. To address this problem, we herein used a nonmodified pristine Ti-Al-C MAX phase (Ti 3 AlC 2) to realize the one-pot room-temperature recovery of gold from highly acidic solutions (pH < 1) in the form of easily collectable bulky ball-shaped Au0 aggregates. High gold selectivity (K d = 2.03 × 106 mL/g) and extraction efficiency (∼99 %) were observed even in the presence of interfering metal ions (Pd2+, Pt4+, Co2+, Ni2+, Cu2+, Zn2+), and the maximum gold extraction capacity (>6000 mg/g) surpassed that of previously reported gold recovery materials. The recovered gold was highly pure (>90 mass%) and contained minimal amounts of the original MAX phase, which obviated the need for intensive postpurification. The results of instrumental analyses suggested that gold recovery relied on electron transfer, similar to cementation, and primarily involved the reduction of solution-phase Au3+ to Au0 via electron transfer from the Ti and Al of Ti 3 AlC 2. Thus, our work demonstrates the significant potential of pristine Ti 3 AlC 2 for the energy-efficient recovery of gold from highly acidic solutions and paves the way for the efficient valorization of e-waste. [ABSTRACT FROM AUTHOR]

[Display omitted] • Innovative cholesterol detection using smartphone-based miniature fluorescent apparatus. • A new hybrid functional catalyst comprising ChOx and Fe 3 O 4 nanoparticles is highlighted. • Smartphone camera captures fluorescence signal and simultaneously analyzed by application. • The quantification of cholesterol in milk samples can be efficiently performed. • This approach delivers on-site detection with low cost and energy consumption. A new hybrid biological-chemical catalyst, magnetic nanoparticles functionalized with cholesterol oxidase (Fe 3 O 4 /APTES/ChOx), was developed for cholesterol detection. In the presence of cholesterol, the enzyme produced H 2 O 2 , which facilitated the generation of fluorescent molecules from the fluorogenic substrate with the assistance of Fe 3 O 4 nanoparticles. A smartphone camera with a miniature fluorescent apparatus was used to assess fluorescence emission. Then, a smartphone application was employed to translate the fluorescence intensity to the red, green, and blue (RGB) domain. The developed approach achieved excellent selectivity and acceptable performances while supporting an onsite analysis approach. The practical operational range spanned from 5 to 100 nM, with a detection limit of 0.85 nM. Fe 3 O 4 /APTES/ChOx was applied for up to four replicates of reuse and demonstrated stability for at least 30 days. The applicability of the method was evaluated in milk samples, and the results were in accordance with the reference method. [ABSTRACT FROM AUTHOR]

Using agrochemicals are considered as an anthropogenic source of heavy metal contamination in water, and ecofriendly remediation tools for removal is desired. Here, we demonstrate material circulation by converting SiO 2 extracted from agrowaste: rice husk ash, into an easily collectable adsorbent: BEA zeolite/Fe 3 O 4 composite, through dry-gel conversion technique. In addition, the synthesized BEA zeolite/Fe 3 O 4 composite was tested for removal of heavy metals for the first time. Instrumental analyses confirmed that incorporated Fe 3 O 4 particles inside BEA zeolites showed no severe effects on its morphologies. Pseudo-second order kinetic and Langmuir isotherm models were found best described the adsorption of three typical toxic heavy metals: Pb(II), Cu(II), Zn(II). Moderate adsorption capacities of 0.675, 0.310, and 0.308 mmol/g for Pb(II), Cu(II), and Zn(II), respectively, following the selectivity order: Pb(II) > Cu(II) ≈ Zn(II) were obtained. The composite adsorbent exhibits magnetic collectability, reusability and stability, indicating its practicality for removal of heavy metals from water. [Display omitted] • First try on heavy metal removal using magnetic zeolite made by dry-gel conversion. • Agrowaste-based-magnetic zeolite used to purify agrochemical-based heavy metals. • The magnetic zeolite was a composite of BEA zeolite with Si/Al∼20 and Fe 3 O 4. • A reusable and magnetically collectable adsorbent for Pb, Cu, and Zn was developed. • The adsorption capacities were 0.675, 0.310, and 0.308 mmol/g for Pb, Cu, and Zn. [ABSTRACT FROM AUTHOR]

Dopamine (DA) concentration in the blood is a critical diagnostic indicator for human illnesses. Thus, the platform-based fluorescence method for DA detection with a smartphone was proven. The detection assay used the complimentary properties of 3-aminopropyl triethoxysilane-functionalized magnetic nanoparticles (MNPs@APTES). In the absence of DA, MNPs@APTES is capable of catalyzing the oxidation of o -phenylenediamine (OPD) by H 2 O 2 to produce the fluorescent species (2,3-diaminophenazine; DAP). The smartphone-based portable fluorescence device can measure the fluorescence intensity of the DAP, which can then be translated into the RGB signal corresponding to the DAP concentration via the smartphone application. However, the RGB intensity was diminished in the presence of DA as a result of the oxidation of DA in an alkaline medium to produce polydopamine (PDA) passivated onto the surface of the MNPs@APTES, which inhibited catalytic activity and produced less DAP. Thus, there is a correlation between the concentration of DA and the degree of fluorescence decrease. This platform demonstrated a high degree of selectivity for DA relative to other analogous substances and potential interferences. In addition, it successfully detected DA levels in human blood serum samples over a linear working range of 1–50 μM with a detection limit of 0.48 μM. [Display omitted] • A sophisticated method for detecting dopamine via fluorescence assay has been demonstrated. • A smartphone equipped with a portable fluorescence device is used to detect a fluorescence signal. • A smartphone application converts the fluorescence intensity to an RGB signal. • Due to a unique dopamine reaction, superior selectivity over other dopamine derivatives is attainable. • Dopamine in real human serum blood can be accurately and precisely analyzed directly. [ABSTRACT FROM AUTHOR]

New strategy to create sunlight-active photocatalysts is a vital research topic in photocatalysis. In this work, ZnO/ZnS heterojunctions were fabricated very easily by thermal oxidation of hydrothermally grown ZnS in air. XRD, FT-IR, FESEM, TEM, XPS, XAS and PL results confirmed that ZnS-500 (ZnS calcined at 500 °C) contains the ZnO/ZnS heterojunctions. The ZnS-500 exhibited the highest photoactivity toward removal of azo dyes (reactive red 141, Congo red) and antibiotics (ofloxacin, norfloxacin) under natural sunlight. The combination of ZnS and ZnO enhances the photoactivity by suppressing the recombination of electron-hole pairs. The photodegradation of the organic contaminants followed pseudo-first order kinetics. The photocatalyst showed structural stability after five cycles. To understand the photocatalytic degradation mechanism, trapping experiment using various scavengers have been investigated. Photogenerated electrons are the crucial species involved in the degradation of the pollutant. It is also proposed that charge transfer at the ZnO/ZnS heterojunction is the Z-scheme type. This work provides a facile strategy for the interfacial engineering of heterojunctions with enhanced photocatalytic performance for environmental remediation. [Display omitted] • ZnO/ZnS photocatalyst was successfully fabricated by a thermal oxidation of hydrothermally grown ZnS in the air. • The enhanced photoactivity toward degradation of azo dyes and fluoroquinolone antibiotics was obtained. • The degradation of the pollutants followed the first-order kinetic model. • The prepared photocatalyst showed the excellent cycling ability after five times of use. [ABSTRACT FROM AUTHOR]

[Display omitted] • Composite β -MnO 2 / activated carbonized coconut fibers was hydrothermally prepared. • Electrochemical properties of electrodes made of these materials were studied. • β -MnO 2 electrode shows a C sc value of 155.08 Fg−1 at 1 Ag−1 and 89.49% retention. • The best electrode shows a C sc value of 320.15 Fg−1 at 1 Ag−1 and 90.87% retention. • Symmetric coin cell gains a notable C sc value of 38.1 Fg−1 at 0.5 Ag−1 in 0–1.8 V. Pure β -MnO 2 (M) nanoparticles (Nps) and M Nps/activated carbonized coconut fiber (ACCF) composites (Cps), (M@ACCF Cps), with ACCF loadings 2.5, 5, 10 and 15% were hydrothermally synthesized. The phase, structure and morphology of ACCF, β -MnO 2 Nps and M@ACCF Cps were characterized using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The chemical surface for oxidation state analysis of samples was studied using X-ray photoelectron spectroscopy (XPS). Specific surface area and pore structure were investigated using a Brunauer, Emmett and Teller (BET) technique. Electrochemical studies revealed a maximum specific capacitance (C sc), 320.15 ± 0.12F g−1, at 1 A g−1 for the M@ACCF10% Cps electrode with the excellent retention, 90.87%, at the 4000th cycle of a GCD test. Symmetric M@ACCF10% Cps coin cells demonstrated an outstanding capacitance value of 38.1 ± 0.2 F g−1 at 0.5 A g−1 over a voltage range of 0.0 – 1.8 V. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ternary photocatalyst based on g-C 3 N 4 /BiOCl/CdS was successfully prepared. • The complete removal of oxytetracycline antibiotic under sunlight was achieved. • The photocatalyst shows good cycling ability with excellent structural stability for seven runs. • The photocatalytic degradation mechanism was proposed. One of the vital topics in photocatalysis research is the development of novel photocatalytic nanomaterials for degradation of toxic pollutants in the natural water under visible light irradiation. Herein we report, for the first time, a facile hydrothermal synthesis of g-C 3 N 4 /BiOCl/CdS heterojunction for complete removal of oxytetracycline (OTC) antibiotic in wastewater. The suppression of electron-hole recombination rate was obtained after creation of the ternary heterostructure. Accordingly, the enhanced photoactivity was found in the prepared heterojunction photocatalyst as expected. Complete removal of OTC was obtained under natural sunlight irradiation. The removal of OTC follows the first-order reaction with the maximum rate constant of 0.023 min−1. The prepared photocatalyst still maintains its structural stability with high photocatalytic performance even after seven times of use. Photogenerated holes are the crucial species involved in the OTC removal while electrons and hydroxyl radicals play a subordinate role. Charge transfer at the interface of the ternary heterojunction is proposed to be the Z-scheme type. The present work shows a promising strategy to create a novel ternary heterojunction with an enhanced photoactivity for complete detoxification of harmful OTC antibiotic in the environment. [ABSTRACT FROM AUTHOR]

Due to 2nd-order Jahn-Teller effect, some M cations such as Ti4+, Sn4+, In3+, Nb5+, Cu2+ and W6+ are allowed to enter the MO 6 octahedral site while maintaining the high-symmetry structure of MTe 3 O 8. Therefore, the series of MTe 3 O 8 compounds when M = Sn, Ti, In 0·5 Nb 0·45 V 0.05 and In 0·4 Cu 0·1 Nb 0·4 W 0.1 were successfully synthesized. Rietveld refinement is utilized to visualize the crystal structures. M − O bonds are expanded because of the larger M cations while the O-M-O angles are distorted slightly. As a result of stereoactive 5 s 2 lone-pair electron of Te4+ in TeO 4 E unit, the structure is flexible as reflected by the small variation of Te–O bond lengths and O–Te–O angles. XANES reveal that the local structures of all compounds are preserved. However, different M cations affect their color and electronic band structures, which can be explained differently by the simple band-to-band transition, the VB-V 3 d electronic transition and the d-d electronic transition. [Display omitted] • In 0·5 Nb 0·45 V 0·05 Te 3 O 8 and In 0·4 Cu 0·1 Nb 0·4 W 0·1 Te 3 O 8 were first studied. • Both short-range and long-range orderings are preserved in all compounds. • XANES and XPS spectra are investigated in detail. • The effects of M cations on electronic structures and optical properties are discussed. [ABSTRACT FROM AUTHOR]

• HTiNbO 5 nanosheets are prepared with a facile hydrothermal method in acid solution. • Using this method, preparation time is reduced from several days to 12 h. • Both acid type and starting KTiNbO 5 are keys to this preparation. • The prepared HTiNbO 5 nanosheets show good photocatalytic activity. Due to the rich chemistry, HTiNbO 5 nanosheets are interesting candidates in many applications but the long preparation time limits their uses. Here, we report a novel fast, and facile preparation of HTiNbO 5 nanosheets by hydrothermal treatment of KTiNbO 5 with acid solution. Investigation on various acids shows that the acid strength and structure determine the product. The bulky structure of citric acid promotes the exfoliation and stabilizes the nanosheets, preventing the decomposition. Nature of KTiNbO 5 is also important as only KTiNbO 5 prepared from molten salt, but not solid-state reaction, gives pure nanosheets. The obtained nanosheets have good crystallinity and photocatalytic activity. Therefore, this novel one-step hydrothermal preparation would play a role in realizing applications of HTiNbO 5 nanosheets and might benefit the exfoliation of other layered oxides. [ABSTRACT FROM AUTHOR]

NH 3 emission during decomposition of LiNH 2 -LiH composite reduces hydrogen storage capacity and poisons fuel cell catalysts. The idea of sandwiching LiNH 2 -LiH pellet with LiH layers (10–30 wt%), reacting with NH 3 and transforming into H 2 is proposed. The LiH-sandwiched LiNH 2 -LiH pellets show no sign of NH 3 release with the hydrogen capacitates of 3.5–4.0 wt% H 2 during the 1st cycle. Upon cycling (the 2nd-6th cycles), decomposition of LiH-sandwiched LiNH 2 -LiH pellet with the low amount of LiH layer (10 wt%) shows NH 3 signal, while that with 30 wt% LiH layers liberates only hydrogen with the storage capacities of 2.3–2.6 wt% H 2. Effective dehydrogenation and reversibility of the 30 wt% LiH-sandwiched LiNH 2 -LiH pellet are explained by not only sufficient content and mechanical stability of LiH layers but also the formation of the new active phases (LiH 1−x F x and Li 2 NH 1−y F y). • New idea of sandwiching LiNH 2 -LiH composite with LiH layers. • Excellent suppression of NH 3 release upon de/rehydrogenation cycles. • Significantly improved de/rehydrogenation kinetics and reversible H 2 capacities. • Detailed reaction mechanisms upon hydrogen exchange reaction. • Formation of new catalytic and reversible phases of LiH 1-x F x and Li 2 NH 1-y F y. [ABSTRACT FROM AUTHOR]

A sunlight responsive WO 3 /AgBr heterojunction photocatalyst was prepared using hydrothermal and chemical precipitation methods. The photocatalyst with band gap of 2.93 eV exhibited high efficiency of 86% toward degradation Rhodamine B (RhB) dye under visible light. Interestingly, nearly complete degradation of RhB dye and ofloxacin (OFL) antibiotic under natural sunlight was achieved. Creation of the WO 3 /AgBr heterojunction is a promising strategy for enhancement of the photoactivity. This may be due to a decrease of charge carrier recombination rate at the interface and an increase in visible light absorption range of the resultant photocatalyst in comparison to those obtained from the pristine photocatalysts. Photogenerated hole plays the major role in photodegradation of the pollutant. The photocatalyst remains stable and still shows high efficiency after five consecutive cycles confirming its excellent cycling ability. This research demonstrates a promising performance of the sunlight active WO 3 /AgBr heterojunction photocatalyst for detoxification of dye and antibiotic in wastewater by utilization of an economical solar energy. [Display omitted] • A heterojunction photocatalyst based on WO3/AgBr was successfully prepared. • Complete removal of Rhodamine B (RhB) dye under natural solar light was achieved. • The photocatalytic degradation of both dye and antibiotic follows the first-order reaction. • The photocatalyst shows excellent structural stability and cycling ability after five cycles. [ABSTRACT FROM AUTHOR]