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BACKGROUND: Palladium nanoparticles can act as a shuttle to accelerate the extracellular electron transfer (EET) by exoelectrogens. Through the EET process, microorganisms drive the redox cycle of many substances. The palladium nanoparticle has a variety of catalytic activities and activities can be significantly improved by combining with the active effects of microorganisms. RESULTS: In this study, Staphylococcus saprophyticus JJ‐1 was utilized as a biological template carrier to synthesize palladium nanoparticles that were immobilized on the bacterial surface. The morphology and composition of palladium were characterized by various techniques including transmission electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. Furthermore, the hydrogenation activity of the synthesized Pd was tested at room temperature and atmospheric pressure using methyl orange as a model pollutant. Electrochemical characterization was carried out by cyclic voltammetry and potentiostatic measurements. The research demonstrated that palladium nanoparticles acted as both electronic mediators and catalysts in the dye reduction process, while S. saprophyticus JJ‐1 contributed to stabilizing nanoparticles and electrochemical activity. The synergistic effect between these two components significantly enhances MO degradation efficiency. CONCLUSION: This study presented an energy‐saving method to synthesize an integrated catalyst based on the synergistic interaction between biomass and nanoparticles, offering a novel approach for developing environmentally friendly, cost‐effective, and efficient integrated catalysts. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Polyaniline (PANI) is a promising conducting polymer for surface modification of TiO2 to overcome limitations of the use of visible light and attain increased photocatalytic efficiency for the removal of organic contaminants. In this study, a series of polyaniline modified TiO2 (PANI-TiO2) composites were prepared by using "in-situ" chemical oxidation polymerization method. The composites were systematically characterized by Fourier transform infrared spectroscopy (equipped with an attenuated total reflection accessory, FTIR-ATR), Raman spectroscopy, X-ray diffractometry (XRD), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDAX), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible diffuse reflectance spectroscopy (UV-DRS), photoluminescence spectroscopy (PL), nitrogen (N2) physisorption (Brunauer − Emmett − Teller surface area (SBET) and Barrett-Joyner-Halenda (BJH) pore size analysis), thermogravimetry-derivative thermogravimetry (TG-DTG) techniques. XRD patterns of PANI-TiO2 composites confirmed both the amorphous phase of PANI and the crystalline character of TiO2. TG/DTG analysis complemented the XRD profiles that the interactions between PANI and TiO2 resulted in a more stable PANI-TiO2 matrix. SEM images displayed the dominant morphology as dandelion-like shapes of PANI being more pronounced with increasing PANI ratios in PANI-TiO2 composites. UV-DRS profiles revealed that the band gap energies of the composites were lower than bare TiO2 expressing a shift to the visible light region. Both PL and UV-DRS analyses confirmed the band-gap reduction phenomenon of PANI modification of TiO2. The incorporation of PANI into TiO2 resulted in a reduction of the surface area of TiO2. The composites were subsequently subjected to photocatalytic activity assessment tests using humic acid (HA) as a model of refractory organic matter (RfOM) under simulated solar irradiation (Uyguner-Demirel et al. Environ Sci Pollut Res 30 85626-85638, 2023). The morphological and structural changes attained upon application of photocatalysis were also evaluated by FTIR-ATR, Raman spectroscopy, XRD, and SEM-EDAX methods in a comparable manner. The FTIR-ATR spectral features of PANI, RfOM and all composites displayed peaks with slight shifts under pre- and post- photocatalytic conditions as well as following dark surface interactions. Besides exhibiting noticeable photocatalytic performance, PANI-TiO2 composites were also proven to maintain stability under non-selective oxidation conditions in the presence of a complex organic matrix. The prepared PANI-TiO2 composites overcoming the limitations of UVA light active bare TiO2 photocatalysis could possibly find a beneficial use as potential catalysts in solar photocatalytic applications. [ABSTRACT FROM AUTHOR]

Bimetallic MOFs offer many advantageous properties rather than monometallic MOFs useful for variety of applications including energy storage and conversion, catalysis, gas separation, sensing, etc. Desired morphology with precise control of crystal size is of utmost importance for specific applications. Microfluidics-incorporated continuous synthesis is demonstrated for bimetallic ZIF-8/67 exhibiting significant nanocrystallinity, porosity and surface area. The microfluidic approach of synthesizing MOF is found very time-efficient in comparison with the conventional techniques. Bimetallic ZIF-8/67 samples were synthesized at different reaction conditions, without adding capping agents and modulators, followed by sophisticated characterization techniques including powder X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, Brunauer–Emmett–Teller analysis and Fourier transform infrared spectroscopy. [ABSTRACT FROM AUTHOR]

In this study, a new type of ceramic composite (PZSC/ZnO) was successfully synthesized using N, P, and S co‐doped carbon microspheres derived from polyphosphazene with zinc oxide. The morphology and structure were characterized by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, scanning electron microscopy, energy‐dispersive spectroscopy, Raman, X‐ray diffraction, BET, and thermogravimetric. Batch experiments were used to explore the adsorption performance under different pH values, initial concentrations, contact times, and temperatures. The results showed that the maximum adsorption capacity of the PZSC/ZnO ceramic composite for uranium was 470.5 mg/g (pH = 5.5, t = 40 min, and T = 25°C). The adsorption process followed the nonlinear Langmuir model and the pseudo‐second‐order kinetic model, demonstrating that the monolayered combination of U(VI) with the PZSC/ZnO ceramic composite and the adsorption mechanism was chemical adsorption. Thermodynamic data revealed that the adsorption was a spontaneous endothermic process. Furthermore, P and N may be involved in the adsorption of uranyl ions through binding to the O atoms from ZnO. The main forces between U(VI) and the PZSC/ZnO ceramic composite were attributed to ZnO and heteroatoms doped in the material. [ABSTRACT FROM AUTHOR]

The current study reports nanostructured CaTiO 3 powder produced by two different novel modified sol-gel methods. The chemical reaction between the calcium oxide (CaO) extracted from chicken eggshell (ES) and titanium (IV) isopropoxide (TTIP) leads to the synthesis of calcium titanate nanopowder. Further leaf extract has also been added in one method which shows the significant effect to reduce particle size up to a certain extent. X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM) were examined to confirm the nanometric particle size. Further, the crystalline structure and phase involvement were also investigated by Rietveld refinement. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–Vis), and photoluminescence spectra (PL) characterization were used to study the functional groups, elemental composition, and optical properties of the material. The photoluminescence emission that occurred in the sample was due to the distortion between [TiO 6 ] – [TiO 6 ] complex clusters causing a difference in the charge density, which can promote a charge transfer between these clusters. The CIE chromaticity coordinates were determined and it shows that the synthesized sample is a promising candidate for the blue color phosphor application. The present phosphors were highly useful for UV chip excited white LED applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Water splitting into hydrogen and oxygen is a promising method for storing sustainable but intermittent energies. Ruthenium compounds are promising for the water-oxidation reaction. Herein, an easy method is employed to load a water-oxidation catalyst (Ruthenium Red; ([(NH 3) 5 RuORu(NH 3) 4 ORu(NH 3) 5 ]Cl 6)) on the surface of the Escherichia coli bacterial template. After the synthetic procedure, the catalyst is characterized by field emission-scanning electron microscopes, high-resolution transmission electron microscopy, visible spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy. Some of the employed methods show that the bacterial template is intact after the synthetic procedure. In the next step, the catalyst is investigated by linear sweep, cyclic, and square wave voltammetry methods. The water-oxidation reaction of the compounds is examined under electrochemical conditions in LiClO 4 (0.25 M) at pH = 6.3. Linear sweep voltammetry shows that the onset overpotential of the water-oxidation reaction of the catalyst is 720 mV (based on extrapolation of the Tafel plot) with a Tafel slope of 226.4 mV per decade. Thus, the presence of Ruthenium Red in the material remarkably increases the activity of the water-oxidation reaction. [Display omitted] • Ruthenium compounds are among the most efficient water-oxidizing catalysts. • Escherichia coli bacterial template/Ruthenium Red is synthesized and characterized. • The electrochemical properties and oxygen-evolution reaction in the presence of this material were investigated. [ABSTRACT FROM AUTHOR]

The azo dyes Reactive Orange‐16 and Reactive Green‐19 were removed using Aliquat‐336‐incorporated Amberlite XAD7HP resin in batch and in a continuous stirrer vessel. The prepared resin was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, Brunauer‐Emmett‐Teller method, and X‐ray photoelectron spectroscopy. The effect of dosage, initial dye concentration, time, pH, and temperature on the removal efficiency of both dyes was evaluated. Equilibrium, kinetic, and diffusion models were fitted to the batch data. Design calculations for single‐stage batch adsorption were done to scale up the process industrially. The resin was regenerated using ethanol. To intensify the process further, continuous studies were performed in a recirculating stirred vessel at different flow rates and stirring speeds. [ABSTRACT FROM AUTHOR]

Herein, a series of Fe–Ti bimetal oxide adsorbents were prepared by reduction–co-precipitation method, and their performance in removing low concentration H2S at room temperature was investigated. The adsorbents were characterized by X-Ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Ultraviolet Visible diffuse reflectance spectroscopy (UV–Vis-DRS), X-Ray photoelectron spectroscopy (XPS) and N2 adsorption–desorption. The results showed that the addition of Ti increased the specific surface area, pore volume and small oligomeric Fe2O3 of ferrihydrite. When the Fe/Ti molar ratio was 8:1, Fe–Ti bimetal oxide formed a large amount of oligomeric Fe2O3, and its specific surface area and pore volume reached 344.99 m2/g and 0.34 cm3/g, respectively. At this time, Fe–Ti bimetal oxide exhibited the highest breakthrough sulfur capacity of 222.8 mg/g. High temperature calcination caused Fe–Ti bimetal oxide to form small specific surface area and pore volume, and produced crystalline α-Fe2O3. And the breakthrough sulfur capacity of Fe–Ti bimetal oxide decreased with the increasing calcination temperature. In addition, the desulfurization process conformed to the unreacted shrinking nucleus model. [ABSTRACT FROM AUTHOR]

This article discusses the effect of silver oxide (Ag 2 O) on structural changes, apatite-forming ability, and bioactivity during addition onto the fluorophosphate glass (FPG) network. The foremost objective of silver incorporation on to fluorophosphate glass is to enhance the antibacterial efficacy of glass material which can be widely used as implants to minimize the post-surgical infections. Silver-added fluorophosphate glasses (AFPGs) with composition of 48P 2 O 5 –29CaO−(20− x)Na 2 O–3CaF 2 − x Ag 2 O (x = 0, 0.3, 0.6, 0.9, and 1.2 mol%) were prepared using conventional glass-melting method followed by rapid quenching technique. The in vitro apatite-forming ability of AFPG was evaluated by immersing the samples in simulated body fluid (SBF) for 21 days. The pH variations of the SBF solution were noted throughout the in vitro study and plotted to estimate dissolution mechanism. The structural properties and compositional estimation of AFPG samples before and after in vitro study were analyzed using X-ray diffractometer, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Cytotoxicity of the prepared AFPG samples was evaluated using MTT assay. The bacteriostatic effect of AFPG samples were studied using different strains of bacteria such as Escherichia coli , Pseudomonas aeruginosa , Klebsiella pneumonia, Staphylococcus aureus , S. epidermidis, and S. mutans. The obtained peaks from XRD analysis at 28.12°, 31.73°, 46.71°, 29.11°, 32.25°, 51.59°, and 67.49° confirm crystalline nature and apatite formation on the glass surface. The attained characteristic FTIR peaks at 560 and 600 cm −1 shows the presence of apatite groups of vibration. The SEM image infers the spherical structure on the glass surface representing the presence of apatite layer and the EDAX graph shows the elemental composition of the prepared glass surface. From the present study, it was noted that glass sample containing 0.9 mol % of Ag 2 O enhanced apatite formation, was less cytotoxic and showed better antibacterial activity. Thus it can be inferred that AFPG0.9 sample can play a significant role in biomedical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • The recovery of chrysocolla was significantly increased after co-modification with EDTA-2Na and CuSO 4. • The modified chrysocolla surface produced copper-containing components with enhanced active sites. • The modified chrysocolla promotes the adsorption of xanthate and enhances hydrophobicity. Chrysocolla is an important copper-oxide ore. However, because of the high surface hydrophilicity, and the small number of active sites, the effective flotation recovery of chrysocolla faces great challenges. In this study, ethylenediaminetetraacetic acid disodium (EDTA-2Na) and CuSO 4 were used as surface modifiers for chrysocolla, and the effects of surface modification on the flotation behavior, xanthate adsorption characteristics, and hydrophobicity of the chrysocolla were systematically investigated using micro-flotation, field-emission secondary electron microscopy with energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, adsorption experiments, and contact angle measurements. Compared to direct flotation, the flotation recovery of chrysocolla after surface modification increased significantly from 25% to approximately 95%. During the modification process, neither EDTA-2Na nor SO 4 2- was effectively adsorbed onto the surface of the chrysocolla. CuSO 4 provided copper ions for to generate of stable copper-containing components on the surface of the chrysocolla, whereas EDTA-2Na acted as a modifier to promote the generation of copper-containing components on the surface of the chrysocolla. Surface modification increased the number and stability of copper-containing components on the chrysocolla surface. This promoted the effective adsorption of xanthate, improved the hydrophobicity of the mineral surface, and enhanced its flotation characteristics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fluorescent phosphorous doped carbon quantum dots from banana stem were synthesized by a facile hydrothermal method. • P-CQDs exhibited excellent water solubility, fluorescent stability and superb biocompatibility. • The P-CQD have been employed for fluorescence-based imaging of biological samples. In this work, a simple hydrothermal process was employed to create phosphorous-doped fluorescent carbon quantum dots (P-CQD) from biomass banana stems. The formation of the P-CQDs and the surface functional group was confirmed through a variety of characterization methods, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), (transmission electron microscopy) TEM, (field emission scanning electron microscopy) FESEM, Fourier transform infrared spectroscopy (FTIR), and (ultraviolet–visible) UV–vis spectroscopy. The quantum yield of the synthesized P-CQDs was found to be 15 %. The P-CQDs showed excitation-dependent photoluminescence (PL) emission behaviour possessing a blue fluorescence under UV light. The P-CQDs was utilized for in vitro cytotoxicity effect on Muscle (L6) and Kidney cells (HEK293). The minimum cell viability for the P-CQD was 96.24 %, while the maximum cell viability was approximately 100 % at a concentration of 400 μg/mL. This study suggests that P-CQDs were non-toxic and could be employed for fluorescence-based cell imaging. [ABSTRACT FROM AUTHOR]

Nowadays, heterogeneous catalysts are preferable to homogeneous catalysts to get more socioeconomic assistance due to multiple recycling. In the current study, CuO/PVA nanocomposites were synthesized via the chemical reduction method, followed by ultra-sonication. The synthesized nanocomposites were confirmed using different characterization techniques, such as X-ray diffraction analysis, scanning electron microscopy, energy dispersive X-ray spectroscopy, dynamic light scattering, zeta potential, Fourier transform infrared spectroscopy, UV-Visible spectroscopy, and X-ray photoelectron spectroscopy. In order to verify their efficacy in the catalytic degradation, engineered CuO/PVA nanocomposites were used for the degradation of Rhodamine B dye in an aqueous medium. Finally, catalytic results exposed that copper oxide nanocatalyst showed an exceptional degradation, greater than 98% using a minimum catalyst dose of 150 μg within 75 s using optimized parameters for NaBH4 (125 μL) and Rhodamine B (0.01 M). To the best of our knowledge, this is the first study of Rhodamine B degradation by CuO/PVA nanocomposite as the catalyst. Certainly, the nanocatalyst presented here is more useful and realistic and hence can be suggested as an effective candidate for the successful degradation of complex dyes at the commercial level. [ABSTRACT FROM AUTHOR]

A reliable sensor for the detection of testosterone was developed by the deposition CuO/CeO2 nanocomposites (NCs) onto glassy carbon electrode (GCE). The wet chemically prepared NCs were totally characterized in detail by X-ray photoelectron spectroscopy, ultraviolet–visible spectroscopy, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis, and energy-dispersive X-ray spectroscopy analysis. In this electrochemical (I–V) approach, a current versus concentration of testosterone is plotted, which is known as calibration of testosterone sensor. It is obtained the linearly over the concentration range of 0.1 to 0.01 nM, which is denoted as a linear dynamic range (LDR). The sensor sensitivity is achieved from the slope of the calibration curve by considering the active surface area of GCE (0.0316 cm2), which is equal to 27.3576 µA µM−1 cm−2. The lower limit for the detection of testosterone is calculated (as 9.30 ± 0.47 pM) from signal–noise ratio at 3. Besides this, the response time, long-time performing stability, and reproducibility of sensor are found reliable and good. The biological samples such as human, mouse, and rabbit serums were tested for the validity of the proposed sensor probe to the selective detection. [ABSTRACT FROM AUTHOR]

Novel Ag2S/PbBiO2Br (Ag2S/PBOB) direct Z-scheme photocatalysts were successfully synthesized for the first time by modifying flower-like PBOB with Ag2S QDs through a hydrothermal and ion-exchange way. The crystal structure, surface state, morphology, element distribution, electrochemical and optical properties of the as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), photocurrent testing, Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS), photoluminescence (PL) technique. The obtained samples were evaluated via degradation of crystal violet (CV) under visible light irradiation. The results show that direct Z-scheme heterojunctions are formed on the interfaces between Ag2S and the PBOB, which enhance the visible light absorbance and efficient separation of photo-generated electron–hole pairs. Moreover, the 5wt%Ag2S/PBOB composite displays the highest photocatalytic activity for the degradation of CV under visible light, where the CV degradation rate is 94.4%, about 1.37 times higher than that for bare PBOB under visible light irradiation for 60 min. The enhanced photocatalytic activity of the Ag2S/PBOB composites can be attributed to strong visible light absorbance and the direct Z-scheme charge transfer mechanism. Moreover, the 5wt%Ag2S/PBOB composite also has a good stability and recyclability and has great potential in environmental protection. In addition, active species trapping experiments confirm that ·O2 and ·OH play a very important role in the degradation process. This work provides new insights and opportunities for establishing photocatalytic models in degradation of organic contaminant. [ABSTRACT FROM AUTHOR]

In this work, nitrogen doped carbon dots (NDCDs) and nitrogen doped carbon dots supported palladium nanoparticles composite (n-Pd@NDCDs) were synthesized through hydrothermal carbonization and thermolytic reduction using Morinda citrifolia (M. citrifolia) fruit and palladium chloride as carbon and Pd precursors, respectively. The synthesized materials viz., n-Pd@NDCDs and NDCDs were duly characterized by high resolution transmission electron microscopy (HR-TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The optical properties of NDCDs were studied by ultraviolet visible (UV–Vis), and fluorescence spectroscopy techniques. Further, the electrocatalytic hydrogen evolution reaction (HER) performance of n-Pd@NDCDs was evaluated by linear sweep voltammetry (LSV), Tafel, and electrochemical impedance spectroscopy (EIS) measurements in 0.5 M aqueous H 2 SO 4. The onset potential of n-Pd@NDCDs was about −0.195 V RHE, which was lower than NDCDS (−0.392 V RHE) and bare glassy carbon (−0.603 V RHE). The calculated Tafel slope values of n-Pd@NDCDs were 135 and 141.8 mV/dec, from the voltammetric and EIS methods, respectively. Moreover, the n-Pd@NDCDs exhibited small overpotential of 0.291 V to attain a current density of 10 mA/cm2. The EIS studies revealed that the HER charge transfer resistance was dropped from 84.3 to 18.3 Ω/cm2 while increasing of potential, which revealed good conductivity and electrocatalytic activity of n-Pd@NDCDs. Thus the present work vouched for the candidature of n-Pd@NDCDs as an effective electrocatalyst for the HER in acidic medium. • n-Pd@NDCDs synthesized by reduction of PdCl 2 and carbonization of M.citrifolia. • n-Pd@NDCDs coated GC exhibits good electrocatalytic activity of HER in 0.5 M H 2 SO 4. • The onset potential of n-Pd@NDCDs/GC is about −0.195 V RHE. • Tafel slope of n-Pd@NDCDs (135 mV/dec) is very smaller than NDCDs and bare GC. [ABSTRACT FROM AUTHOR]

A facile and novel method was developed to improve the conductivity of a cyclodextrin-metal organic frameworks (CD-MOFs) by modifying it with Ketjen Black (KB) and platinum nanoparticles (PtNPs). The structural morphology and composition of this PtNPs/KB/CD-MOFs nanocomposite was characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, elemental mapping, and Raman spectroscopy. The sensor was then evaluated for its ability to detect ofloxacin using cyclic voltammetry, and the results showed that the PtNPs/KB/CD-MOF had high sensitivity, satisfactory stability and good reproducibility. In addition, a great linear range was obtained with a concentration range of 0.08–100 μM and a low detection limit of 0.037 μM (S/N = 3). Therefore, the prepared electrochemical sensor could be successfully used to detect ofloxacin in serum. [ABSTRACT FROM AUTHOR]

The design of photocatalysts, which uses free and available sunlight as a driving force to generate ammonia from nitrogen (N 2) and remove organic pollutants from wastewater, is helpful to develop a sustainable chemical industry. The novel g-C 3 N 4 nanosheet/AgBiS 2 nanocomposite with visible-light response was successfully fabricated for the first time using a simple heating process. The purity, microstructure, morphology, photoelectrochemical, and electronic features of the obtained photocatalysts were studied using X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy (TEM), high-resolution TEM, X-ray photoelectron spectroscopy, diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, photoluminescence, Brunauer–Emmer–Teller surface area, photocurrent responses, and electrochemical impedance spectroscopy. The g-C 3 N 4 nanosheet/AgBiS 2 nanocomposite possessed excellent photocatalytic activity for rhodamine B (RhB) degradation and N 2 fixation upon visible illumination. The photocatalytic ammonium production reached 3780 μmol L−1 g−1 over g-C 3 N 4 nanosheet/AgBiS 2 nanocomposite, increases of 3.15- and 2.85-fold compared to that of g-C 3 N 4 nanosheet and AgBiS 2 , respectively, as well as 99% improvement in degradation efficiency for RhB removal. The improved activity of g-C 3 N 4 nanosheet/AgBiS 2 nanocomposite can be ascribed to the formation of suitable heterojunction, suppressing the recombination of photogenerated charges, while facilitating their transfer. A plausible photocatalytic mechanism was proposed based on the experimental outcomes and photoelectrochemical properties. The g-C 3 N 4 nanosheet/AgBiS 2 nanocomposite proved to be significantly reusable and stable after five and four runs of N 2 fixation and RhB degradation, respectively. [Display omitted] • The g-C 3 N 4 nanosheet/AgBiS 2 nanocomposite was fabricated via a facile heating method. • The photocatalytic efficiency of g-C 3 N 4 nanosheet/AgBiS 2 was higher than bare samples in N 2 fixation and RhB degradation. • The heterojunction formed between the g-C 3 N 4 nanosheet and AgBiS 2 greatly improved the photocatalytic performance. • The g-C 3 N 4 nanosheet/AgBiS 2 nanocomposite possessed excellent reusability for N 2 fixation and RhB degradation. [ABSTRACT FROM AUTHOR]

Herein, a green geopolymer composite was prepared using red mud and granulated blast furnace slag by immobilizing Pb2+ and Cr3+ to improve the utilization rate of red mud for heavy metal solidification and grouting engineering. The mechanical strength, leaching characteristics, and immobilization mechanisms of geopolymer grouts were investigated via Fourier transform infrared spectroscopy, X-ray diffraction, magic angle spinning–nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy–energy-dispersive spectroscopy. Results demonstrate that the mechanical strength of the red-mud-based grout first increased and then decreased with an increasing alkali activator modulus. Moreover, red mud could participate in the geopolymerization reaction because of its aluminosilicate component. Furthermore, both Pb2+ and Cr3+ improved the mechanical strength of red-mud-based grouts at contents of 0.4 and 0.6 wt%, respectively. However, the mechanical strength drastically decreased when the dosages for both were 1.0 wt%. These chemical fractions of Pb2+ and Cr3+ evidence that the soluble and exchangeable fractions could be converted to a carbonate-bound fraction, iron–manganese oxide, and an organic fraction; however, the immobilization rates reached 91.46% and 95.86%, respectively. The characterization results confirm the participation of Pb2+ and Cr3+ in the geopolymerization, and Pb2+ and Cr3+ were immobilized by the chemical bonding and physical sealing effects. [Display omitted] • Effect of red mud and alkali activator on the workability of RMG was analyzed. • The leaching characteristic of Pb2+ and Cr3+ was investigated. • Revealed the immobilization mechanism of Pb2+ and Cr3+ in RMG. [ABSTRACT FROM AUTHOR]

• Phase pure LAFO, LACO and LCFO were prepared by gel-burning method. • LACO showed lower electron-holes pair recombination than LCFO and LAFO. • Photocatalytic degradation of MB was follows the order LACO > LCFO > LAFO. • Holes played significant role in the MB degradation over LACO. • The LCAO catalyst possessed good recycling efficiency up to 4 cycles. Organic dye contaminants which are frequently detected in water bodies have attracted significant attention as they are mostly non-biodegradable. These contaminants pose severe environmental and health risks. In the present work, perovskites of compositions LaAl 0.5 Fe 0.5 O 3 , LaAl 0.5 Cr 0.5 O 3 , LaCr 0.5 Fe 0.5 O 3 (here after LAFO, LACO and LCFO respectively) were prepared by ethylene glycol assisted gel burning method. The as prepared materials were subjected to powder X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy-selected area electron diffraction (TEM-SAED), N 2 adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR), Raman, UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) techniques for characterization. Rietveld refinement was carried for all the compositions and deduced the unit cell parameters. Bandgap energy was obtained for all the three perovskites from their DRS profiles. The FT-IR and Raman spectra gave characteristic M-O and O-M-O (M = La, Cr, Fe, Al) vibrational modes. The photocatalytic activity of these compounds was examined against the degradation of methylene blue (MB). The participation of transient species in the degradation of MB, mechanism of photodecomposition and stability of the catalyst were also presented. A promising LACO catalyst with perovskite structure has been synthesized for efficient photocatalytic degradation of MB under visible light irradiation. The degradation mechanism over LACO was also proposed. [Display omitted] [ABSTRACT FROM AUTHOR]

• A novel method for simulating chalking of silicone rubber is proposed. • The similarity between naturally and artificially chalked samples is confirmed. • Diethylamine helps tetramethylammonium hydroxide work selectively at the interface. • Filler-polymer interface increases the probability of chalking. Chalking is a universal aging phenomenon for silicone rubber (SR) used in external insulation. Under laboratory aging conditions, chalking is difficult to simulate. In this study, a new method based on the combination of tetramethylammonium hydroxide (TMAH) catalyst and diethylamine (DEA) solvent was proposed for the efficient artificial reproduction of SR chalking. Comparative analysis of the naturally and artificially chalked layers was performed through scanning electron microscopy, energy dispersive X-Ray spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy, among others. The macroscopic observation and microstructure analysis confirmed the similarity between the two chalking layers. According to the results of pyrolysis-gas chromatography-mass spectrometry, a mechanical model was established, which explained the reaction selectivity of TMAH on the filler–polymer interface, thereby resulting in the separation of the fillers and matrix (chalking). Finally, the proposed method for simulating chalking was used to verify the aging resistance of SR with different filler contents. The higher filler content introduced more interfaces, which increased the probability of chalking. [ABSTRACT FROM AUTHOR]

The photocatalytic oxidation of organic dye molecules is an active area of present day's research. In this context, a new visible-light-driven photocatalyst of Bi-N codoped SnO2 nanoparticles was prepared by hydrothermal method. The structural, morphological and optical properties were characterized by using UV-visible-diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller and X-ray photoelectron spectroscopy analysis. Bi-N codoped SnO2 showed an enhanced photocatalytic activity for the degradation of crystal violet by facilitating electron-hole pair separation. The highest crystal violet degradation was found in 97% (with 72.8% chemical oxygen demand removal) achieved with Bi, N-SnO2 concentration of 0.2 g/L, initial dye concentration 5 µM, pH 7 and irradiation time 180 min. Bi, N codoping in tin oxide had synergetic effect in enhancing its photocatalytic activity. The effects of doping on the SnO2 nanoparticles included reduced energy band gap, high crystalline and small crystallite size as well as increased photocatalytic activity. [ABSTRACT FROM AUTHOR]

Highly electroactive transition metal oxides have been received great potential in antibiotic drug electrochemical sensors due to excellent features including ease of preparation, a large number of active sites, good conductivity, high stability, and selectivity. In this work, the perovskite-type silver titanate (Ag 2 TiO 3) was synthesized by ultrasound-assisted coprecipitation method. The structural and morphology were examined using typical analytical techniques such as X-ray diffraction (XRD) Fourier transform infrared spectroscopy (FT-IR), Raman spectrometry, field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) analyzes confirmed the purity and the chemical composition of as-prepared Ag 2 TiO 3. The Brunauer−Emmett−Teller analysis (BET) of as-synthesized Ag 2 TiO 3 displayed a specific surface area of 48.485 m2 g−1 resulted in improved charge transfer resistance (R ct) of 695 Ω. The cyclic voltammetry (CV) analysis revealed the superior electrochemical performance of Ag 2 TiO 3 than other electrodes towards metronidazole (MTZ) detection. Under optimized differential pulse voltammetric (DPV) studies, the modified electrode exhibits a wide linear range of 0.1–104.3 μM with the lowest detection limit of 0.011 μM and a sensitivity of 0.371 μA μM−1 cm−2. Furthermore, the fabricated sensor displayed excellent cyclic stability, reproducibility, repeatability, and noticeable selectivity in potentially effective interfering compounds for the detection of MTZ. The constructed electrode delivered good sensitivity to MTZ in urine and tablet with acceptable recoveries. Schematic diagram of as-synthesized Ag 2 TiO 3 towards electrochemical sensing of MTZ. [Display omitted] • Perovskite-type Ag 2 TiO 3 was prepared by a simple ultrasonication method. • The as-synthesized Ag 2 TiO 3 modified electrode was optimized for the loading catalyst, pH, scan rate, peak current, and peak potential at the electrochemical determination of MTZ. • The fabricated sensor shows an extensive linear response from 0.1 to 104.3 μM with a low detection limit of 0.011 μM. • MTZ was successfully applied in real samples with good sensitivity and appropriate results. [ABSTRACT FROM AUTHOR]

• The CeO 2 /Co 3 O 4 porous nanosheets were successfully prepared using Chinese rose petals as biotemplate. • The photodegradation rate of MB in 70 min was 96.42%, and TC in 30 min was 85.35%. • The results in this work show that the proposed algorithm has high stability and reusability. CeO 2 /Co 3 O 4 porous nanosheets were prepared by biotemplate for photo-catalytic degradation of methylene blue (MB) and tetracycline (TC).The samples were systematically characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), nitrogen physical adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS). The results showed that the CeO 2 /Co 3 O 4 porous nanosheets prepared by the petal biotemplate successfully replicated the morphology of the template. The band gap energies of E g1 : 1.70 eV, E g2 : 2.42 eV, and E g3 : 3.56 eV were calculated by UV–Vis diffuse reflectance spectroscopy. The results showed that the removal rate of MB within 70 min was 96.42% and the removal rate of TC within 30 min was 85.35%. The degradation process was consistent with the first-order reaction kinetics. The results in this work show that the proposed algorithm has high degradation efficiency, stability and reusability. [ABSTRACT FROM AUTHOR]

• The Cu/HAP/ZnFe 2 O 4 novel composite was designed in a facile synthetic route. • Different characterization techniques confirmed the synthesis of the composite. • The catalyst able to reduced p-nitrophenol 100% just in 5 s. • The performance of the catalyst was excellent with minimal reaction conditions. • The catalyst is highly stable and can be effectively reused for 5 cycle. In this study, we reports the synthesis, characterization and application of the novel Cu/HAP/ZnFe 2 O 4 nanocomposite. The composite was synthesized in three steps and well characterized by various characterization techniques such as X-ray photoelectron spectroscopy, fourier transforms infrared spectroscopy, powdered X-ray diffraction analysis, scanning electron microscopy, transmission electron microscope, selected area electron diffraction studies, vibrating sample magnetometer analysis and energy dispersive X-ray spectroscopy. The nanocomposite Cu/HAP/ZnFe 2 O 4 show excellent catalytic reduction of p-nitrophenol in the presence of sodium borohydride at room temperature. Remarkably the catalyst took less than five-second for complete (100%) reduction of p-nitrophenol to the corresponding p-aminophenol. The composite was very stable and show the same catalytic efficiency for five consecutive cycles. This recyclable, environment-friendly, highly stable and low-cost catalyst has the enormous potential in the transformation of p-nitrophenol to the corresponding p-aminophenol as well as to remove the hazardous chemicals such as p-nitrophenol from the environment as a whole. [ABSTRACT FROM AUTHOR]

In this communication, indium oxide (In 2 O 3) and Zn-doped In 2 O 3 nanoparticles with different zinc percentage (0–5%) have been prepared by a facile chemical process. A variety of analytical tools such as X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV–Visible, photoluminescence spectroscopy, photocatalytic measurements and impedance spectroscopy were employed to assess the characteristics of prepared nanoparticles (NPs). From XRD analysis it is observed that all samples exhibit pure cubic phase with highly crystalline nature. XPS spectra revealed the composition and chemical state of Zn-doped In 2 O 3 NPs. The estimated optical band gap was found to decrease with increase of Zn concentration. Magnetic hysteresis exhibited that pure and Zn-doped In 2 O 3 NPs possess ferromagnetic behavior at room temperature. Dielectric constant (ε ') as well as dielectric loss (ε ") decreases exponentially in lower frequency range, but remains almost constant in higher frequency range. Moreover, Zn(5%)-doped In 2 O 3 nanoparticles showed much higher photocatalytic activity as compared with pure In 2 O 3 nanoparticles towards degradation of hazardous methylene blue dye. The results of present study demonstrated that synthesized nanoparticles may be employed efficiently as environmentally convenient photocatalyst for industrial effluent treatment. • Pure and zinc (Zn) loaded indium oxide (In 2 O 3) nanoparticles were prepared by a facile chemical process. • Structure and morphology characterization was performed by XRD and SEM. • The dielectric constant and dielectric loss have been investigated as a function of frequency 120 Hz to 0.1 MHz.. • In 2 O 3 –Zn nanoparticles exhibit superior photocatalytic activity than that of pure In 2 O 3 NPs. • The photocatalytic mechanism was proposed. [ABSTRACT FROM AUTHOR]

Natural bioactive compounds have been widely used as templets in the stabilization and functional improvement of nano-selenium (SeNPs) in recent years. Herein, green tea nano-aggregates, bioactive colloidal particles spontaneously assembled by tea polyphenols, proteins, and carbohydrates in tea infusions, were introduced as a novel templet for the green synthesis of SeNPs via the ascorbic acid-sodium selenite (Na 2 SeO 3) redox reaction. Primarily, hydrodynamic diameter and Zeta potential of SeNPs produced under different conditions were analyzed by dynamic light scattering and laser Doppler velocimetry. Accordingly, the ratio between ascorbic acid and Na 2 SeO 3 of 8:1 (mmol: mmol) with 500 mg/L of green tea nano-aggregates at 40 °C for 1 h was controlled for SeNPs preparation. On this basis, red, zero-valent, amorphous and spherical SeNPs of 50 nm in diameter with high electrostatic stability (−41.5 mV) were successfully constructed and characterized via transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. SeNPs exhibited stronger inhibition on the proliferation of carcinoma cells HCT 116 and MDA-MB-231 compared with Na 2 SeO 3. This work provides an innovative strategy for the green synthesis of SeNPs and advances our basic knowledge about the interactions between SeNPs and templets. Image 1 • Green tea nano-aggregates have peculiar chemical structure and composition. • Polysaccharide and protein are the main components of green tea nano-aggregates. • Green tea nano-aggregates could effectively stabilize nano-selenium. • Green tea nano-aggregates could strengthen nano-selenium anti-proliferative activity. • Green tea nano-aggregates nano-selenium is the sphere shape of amorphous selenium. [ABSTRACT FROM AUTHOR]

Utilization of bauxite residue is an urgent issue confronting the worldwide alumina industry. A CaTiO 3 -rich material has been successfully collected from bauxite residues based on our previous work, and the possibility of applying this obtained CaTiO 3 as photocatalyst for degradation of rhodamine B was evaluated in this study. X-ray diffraction, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, X-ray photoelectron spectroscopy, UV–vis spectroscopy, photoluminescence microscopy, and Brauner-Emmet-Teller surface area analyzer were employed to characterize the CaTiO 3 samples. Interactive effects of dominant factors on degradation of rhodamine B were examined through surface response methodology and optimal conditions were obtained. H 3 PO 4 acidification was effective to enhance the photocatalytic activity of CaTiO 3. More than 10 h was required for RhB degradation in presence of CaTiO 3 while only 3 h was needed to achieve 85% removal of RhB using the acidified CaTiO 3. CaTiO 3 has larger band gap and lower separation efficiency of photoelectrons-hole pairs than TiO 2 , but H 3 PO 4 acidification significantly reduced the recombination of photoelectrons-hole pairs and thus made more photoelectrons/holes participate in reactions. This study has validated a promising routine towards fully comprehensive utilization of bauxite residues, and simultaneously addressed a novel idea for using solid-waste to treat wastewater, thereof was very favorable to the sustainable development of environment. Image 1 • CaTiO 3 derived from bauxite residues proved feasible photocatalyst. • Interactive effect of factors was evaluated by response surface methodology. • H 3 PO 4 acidification improved the photo-activity of CaTiO 3. • Reduced recombination of photoelectron-holes was key for enhanced performance. [ABSTRACT FROM AUTHOR]

• PLA and Au@PDA NPs blend electrospinning to produce PLA-Au@PDA nanofibers. • In situ assembly of well-dispersed Ag nanoparticles to produce PLA-Au@PDA@Ag nanofibers. • PLA-Au@PDA@Ag nanofibers exhibited good hydrophilicity and excellent antibacterial abilities. Nanofibrous membranes which exhibit bacteriostatic functions are a good strategy to prevent microorganisms from adhering to the surface of biomaterials. Here, we report the synthesis of such a nanofibrous membrane which can be applied to biological coatings to reduce bacteriostatic functionality. Ascorbic acid was utilized to reduced chloroauric acid to gold nanoparticles (AuNPs). Dopamine was then polymerized upon AuNP surfaces by ultrasound-assistance, to synthesize core-shell structured polydopamine-coated AuNPs (Au@PDA NPs). The Au@PDA NPs were then mixed with polylactic acid (PLA) for electrospinning into cylindrical nanofibers (136.6 nm diameter). PLA-Au@PDA nanofibrous membranes were finally immersed in silver nitrate for in situ reduction into a silver nanoparticle (AgNP) coating to yield PLA-Au@PDA@Ag nanofibers. The PLA-Au@PDA@Ag nanofibers were characterized based on field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and contact angle analyses. The antibacterial properties of the PLA-Au@PDA@Ag nanofibers were examined based on the optical density absorbance of bacterial cell suspensions, traditional colony plate counts, zone inhibition analyses, and field-emission scanning electron microscopy. Escherichia coli and Staphylococcus aureaus respectively served as Gram negative and positive bacterial models of industrial relevance. The data conclusively illustrates the antimicrobial and biomedical applications of PLA-Au@PDA@Ag nanofibers. [ABSTRACT FROM AUTHOR]