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• Construct a superactive, friendly and cost-effective catalyst from natural tourmaline. • Catalyst is superior to P25 in activating PMS and degrading antibiotic in real waters. • It can degrade tetracycline in a wide concentration range. • Above 98.7% of tetracycline was degraded in seawater within 5 min. • The catalytic reaction mechanism was explored and proposed. • The eco-friendly catalyst can be recycled and reused for multiple cycles. Reasonably designing highly active, environmentally friendly, and cost-effective catalysts for efficient elimination of pollutants from water is desirable but challenging. Herein, an efficient heterogeneous photo-Fenton catalyst tourmaline (TM)/tungsten oxide (WO 3-x) (named TW10) containing tungsten/boron/iron (W/B/Fe) synergistic active centers and 90% of cheap natural tourmaline (TM) mineral rich in Fe and B elements. The TW10 catalyst can quickly activate peroxymonosulfate (PMS) to generate massive active free radicals, which may induce the rapid and efficient degradation of tetracycline (TC). The TW10/PMS/Visible light system can effectively degrade up to 98.7% of tetracycline (TC) in actual waters (i.e. seawater, Yellow River, and Yangtze River water), and the catalytic degradation rates reach 1.65, 5.569, and 2.38 times higher than those of TM, WO 3-x , and commercial P25 (Degussa, Germany), respectively. In addition, the catalyst can be recycled and reused multiple times. Electron spin resonance spectroscopy (EPR), X-ray photoelectron spectroscopy (XPS), and liquid chromatograph-mass spectrometer (LC-MS) analyses confirm that the synergistic catalytic effect of W/B/Fe sites on the TW10 catalyst accelerates the electron transfer between Fe(II) and Fe(III), as well as between W(V) and W(VI), and thus promotes the rapid degradation of TC. The catalytic reaction mechanism and degradation pathway of TC were explored. This work provides a feasible route for the design and development of new eco-friendly and efficient catalyst. [Display omitted] [ABSTRACT FROM AUTHOR]

To investigate the tribological properties of polycrystalline diamond compact (PDC), different additives including graphene, molybdenum disulfide (MoS 2), and a combination of graphene + MoS 2 were utilized. The microstructure and chemical reactions of PDC were analyzed using techniques such as atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The focus was on the formation and degradation of the friction film. The findings revealed that both graphene + MoS 2 exhibit excellent lubrication properties, forming a protective friction film on the surface of PDC. Furthermore, the combined use of graphene + MoS 2 demonstrated a synergistic effect, resulting in enhanced wear resistance of PDC compared to the individual use of graphene or MoS 2 alone. [ABSTRACT FROM AUTHOR]

Litsea cubeba is a characteristic woody oil resource in Hunan. As a solid waste of woody oil resources, Litsea cubeba kernels are rich in Litsea cubeba kernel oil with a carbon chain length of C10–12 fatty acid. In this work, aliphatic hydroxamic acids (AHAs) with carbon chain lengths of C10–12 were prepared from Litsea cubeba kernel oil via methylation and hydroximation reactions. The adsorption and hydrophobicity mechanism of AHA towards wolframite was explored by contact angle, zeta potential, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The flotation results demonstrated that AHA was a superior collector than the traditional collector such as benzoyl hydroxamic acid (BHA). Zeta potential and contact angle results have shown that AHA was adsorbed on the surface of the Fe(III)-activated wolframite in its anionic form, which significantly improved the surface hydrophobicity of wolframite. FTIR and XPS revealed that AHA was chemically adsorbed on the surface of Fe(III)-activated wolframite in the form of a five-member ring, which made the hydrophobic chain reach into the solution, come in contact with bubbles, and achieve flotation separation. [ABSTRACT FROM AUTHOR]

In this study, a natural gas purification plant adopts open circulating water system, which cannot work properly and hinder the normal production of natural gas due to the problems such as scaling and blockage in the operation of heat exchanger device was reported. Qualities of the make‐up water and recirculating cooling water were evaluated by parameters such as hardness, alkalinity, pH, and conductivity. X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and optical microscope were employed to study the crystal structure, composition, and morphology of the scale deposits. The flow rate of the water in the tube bundle was calculated according to the design scale of these exchangers. The Langelier Saturation Index (LSI) was used to analyze the scale tendency of the cooling water system. The scale inhibition performance of the inhibitor was verified by static inhibition method. Results show that the scale mainly contains calcium carbonate, and the quality of circulating water is reasonably controlled with a proper range. However, there are three units sharing one cooling water system, of which the flow rate cannot be adjusted according to the actual heat load. The calculation results confirmed that the circulating water velocity in the tube bundle did not exceed 0.9 m/s. Although the scale inhibitor has a scale inhibition efficiency of more than 90% for the simulated circulating water at 80°C, the LSI analysis results showed that the high local temperature on the surface of the tube bundle caused by the low flow rate of water will increase the scaling tendency of the heat exchanger. Furthermore, the untimely injection of the inhibitor in the daily management and operation also greatly increased the risk of system scaling. This paper proves that the scaling of circulating water heat exchanger in the purification plant is mainly caused by device design and poor daily management. In order to prevent future failures, potential solutions and mitigation strategies were put forward. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ultrasonic synthesis was used to create a range of sulfur-functionalized metal–organic frameworks (S-MOFs: Bi-TDC) that exhibit piezo photocatalytic properties. • Rapid reduction of hexavalent chromium (Cr(VI) using piezo photocatalysis. • A method and reduction mechanism for reducing hexavalent chromium (Cr(VI)) is proposed. The United Nations' Sustainable Development Goals (SDGs) are significant in guiding modern scientific research. In recent years, scholars have paid much attention to MOFs materials as green materials. However, piezo catalysis of MOFs materials has not been widely studied. Piezoelectric materials can convert mechanical energy into electrical energy, while MOFs are effective photocatalysts for removing pollutants. Therefore, it is crucial to design MOFs with piezoelectric properties and photosensitivity. In this study, sulfur-functionalized metal–organic frameworks (S-MOFs) were prepared using organic sulfur-functionalized ligand (H 2 TDC) ultrasonic synthesis to enhance their piezoelectric properties and visible light absorption. The study demonstrated that the S-MOFs significantly enhanced the reduction of a 10 mg/L solution of hexavalent chromium to 99.4 % within 10 min, using only 15 mg of catalyst. The orbital energy level differences of the elements were analyzed using piezo response force microscopy (PFM) and X-ray photoelectron spectroscopy (XPS). The results showed that MOFs functionalized with sulfur atom ligands have a built-in electric field that facilitates charge separation and migration. This study presents a new approach to enhance the piezoelectric properties of MOFs, which broadens their potential applications in piezo catalysis and piezo-photocatalysis. Additionally, it provides a sustainable method for reducing hexavalent chromium, contributing to the achievement of sustainable development goals, specifically SDG-6, SDG-7, SDG-9, and SDG-12. [ABSTRACT FROM AUTHOR]

Interestingly, the Nd3+ ions are incorporated into the crystal lattice and migrate to the CdS/Sb 2 (S,Se) 3 interface after the doping process, thereby enhancing the efficiency of the device in terms of providing a preferential crystal orientation and lower defect density. [Display omitted] • Nd3+ doping for Sb 2 (S,Se) 3 is carried out via modified hydrothermal deposition. • These ions can be incorporated into the crystal lattice. • Most of the ions migrate to the CdS/Sb 2 (S,Se) 3 interface after doping. • Photoelectrical parameters and device stability are both improved after doping. • We provide an effective doping strategy for Sb 2 (S,Se) 3 solar cells. Doping the light absorber layer of antimony chalcogenides with extrinsic ions is an effective approach for improving their photovoltaic quality. These dopant ions generally reside at positions other than the crystal lattice or form an alloy (e.g., AgSb(S,Se) 3) with a poor device performance. Therefore, incorporating such ions into an antimony chalcogenide lattice such that there is a positive influence on device quality would be highly useful. Herein, doping of Nd3+ for Sb 2 (S,Se) 3 is carried out via a modified hydrothermal deposition process. Notably, these ions are incorporated into the crystal lattice and migrate to the CdS/Sb 2 (S,Se) 3 interface after doping, which are characterized using X-ray diffraction, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry. Nd3+ doping produces benign effects on the crystal orientation, film morphology, optoelectronic properties, and defect passivation of the Sb 2 (S,Se) 3 films. Consequently, all the photoelectrical parameters of Sb 2 (S,Se) 3 solar cells doped with Nd3+ are enhanced, delivering a remarkable efficiency of 8.24 %. Furthermore, the best device stored in air only shows a slight decrease in efficiency in the 2400-h aging test. Overall, this study provides an effective doping strategy to improve the photovoltaic quality of Sb 2 (S,Se) 3 films. [ABSTRACT FROM AUTHOR]

• Sub-critical water is mild and suitable for in-situ conversion of oil shale. • Sub-critical water tends to extract aliphatics instead of aromatics and oxygenates. • Sub-critical water can inhibit the condensation of aromatic carbons. • Sulfur compounds can be converted into sulfone or thiophene in sub-critical water. • Hydroxyl and oxy heterocycle may be formed after the crack of oxy-groups. Sub-critical water extraction is being considered as a potential in-situ conversion process for deep-lying oil shale. In this study, low-grade oil shale cores from the Nong'an oil shale in-situ conversion pilot were extracted by sub-critical water at 350 °C for 5–100 h. The results show that the maximum oil yield obtained at 50 h was 3.68 %, higher than the 3.45 % yield from Fischer assay analysis. It shows that sub-critical water extraction can obtain more organic matter than retorting. Additionally, a large amount of bitumen remained in the shale matrix after sub-critical water extraction. Its content reached maximum value when the kerogen was completely cracked at about 70 h. The gas chromatography-mass spectrometry (GC–MS) was conducted to analyze the components of the shale oil and residual bitumen. The results showed that n -alkanes, iso -hydrocarbons, aromatics, and n- alkenes were the major components of the kerogen cracking products. More aliphatic hydrocarbons could be extracted by sub-critical water, but more heteroatomic compounds would remain in the shale residue. This illustrates the selective extraction of more aliphatic hydrocarbons by sub-critical water during hydrolysis. The solid-state 13C NMR results of kerogen indicated that, under the action of sub-critical water, the long aliphatic chain in kerogen could be easily pyrolysis and released. The condensation of aromatic carbons was inhibited during the cracking of kerogen. The X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) analysis revealed that, some sulfur-containing functional groups would be oxidized or cyclized to sulfone and thiophene, and some oxygen-containing components might form hydroxyl and oxy heterocycle after cracking in sub-critical water. Anyway, sub-critical water extraction can more effectively present the in-situ conversion process. [ABSTRACT FROM AUTHOR]

The migration and transformation behavior of selenium during coal chemical looping gasification (CLG) under the impact of a CuO/Bentonite (Ben) oxygen carrier (OC) were studied in a batch fluidized bed reactor. In the CLG process, the total percentage of selenium released in gaseous phase was 73.06%. In the conventional gasification process, 91.71% of the total selenium was released in a gaseous state. The addition of CuO/Ben OC apparently promoted the transformation from gaseous selenium to particulate selenium. The oxygen–carbon ratio (O/C) played an important role in affecting the fraction of gaseous selenium released in the gasification process, with results showing that the amount of selenium adsorbed by CuO/Ben OC was added along with the increase in OC. By means of X-ray photoelectron spectroscopy (XPS) characterization, we found that the reduced CuO/Ben OC contained a small amount of Cu2Se due to the oxidation and adsorption of selenium onto their porous surface. The regeneration performance of the CuO/Ben OC was favorable after 10 regeneration cycles of the CLG process. The increase in the pore volumes and specific surface areas contributed to the enhanced capacity of retaining selenium for CuO/Ben OC. [ABSTRACT FROM AUTHOR]

Supercritical water (SCW) has strong reactivity and the ability to fuse non-polar substances, but it requires higher corrosion resistance of structural materials. To select reliable candidate materials for a supercritical water system, this study investigated the corrosion behavior of 304 stainless steel (304 SS) in supercritical water (798 K/24 MPa). After soaking 304 SS in supercritical water for 200 h, the oxidation kinetics, surface morphology, and element diffusion were studied by weight measurement, scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersion spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The surface of 304 SS shows an isolated and discontinuous oxidation deposition. It is determined that the oxide layer is a single layer, mainly composed of Fe-Cr-rich spinel, with a small amount of magnetite attached to the surface of the oxide layer. Besides, the oxidation mechanism was also studied since some pores were found on the surface due to pitting. [Display omitted] • Corrosion behavior of 304 stainless steel is investigated in supercritical water. • Oxidation kinetics, surface morphology, and element diffusion were studied • Surface of 304 SS shows isolated and discontinuous oxidation deposition [ABSTRACT FROM AUTHOR]

[Display omitted] It is imperative to seek for novel materials with pronounced gas sensing performance towards triethylamine for the sake of human health. Herein, we successfully fabricate an outstanding triethylamine sensor based on CdS/ZnO composite with 0D/2D structure, which are prepared by in-situ growth of CdS quantum dots on ultra-thin ZnO nanosheets. The ratios between the two ingredients are adjusted and their effect is evaluated. The optimal sample exhibits the lowest operating temperature of 200 °C, the highest response value of ~20 and the fastest response time of 2 s. Besides, it also has the virtues of durable stability, excellent selectivity and superior anti-interference ability. The mechanism behind the aforementioned intriguing performance is investigated by X-ray photoelectron spectroscopy, Kelvin probe and density function theory (DFT) simulation. All the results verify that the enhanced gas sensing properties are derived from splendid 0D/2D structure, n - n heterojunction and large specific surface area. Additionally, this study opens an avenue for designing sensors with 0D/2D structure. [ABSTRACT FROM AUTHOR]

A sensitive and selective voltammetric biosensor composed of layer-by-layer (LbL) self-assembly of positively charged poly(diallyldimethylammonium)-wrapped oxidized single-walled carbon nanotubes (PDDA-oSWCNTs), negatively charged serotonin (5-hydroxytryptamine, 5-HT)-specific aptamer, and tyrosinase on Au nanoparticles deposited screen printed carbon electrode was developed for measurement of 5-HT. Surface characteristics of 5-HT biosensor were explored using scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy. The respective effects of 5-HT-specific aptamer and oSWCNTs on the detection of 5-HT were investigated by differential pulse voltammetry (DPV). The peak current at the potential of 0.29 V (vs. Ag/AgCl) increased with respect to 5-HT concentration resulting in two dynamic ranges from 0.05 to 0.5 and 1 to 20 μM with a limit of detection of 2 nM from the LbL biosensor in buffer solution, which were better than those without the LbL of aptamer and oSWCNTs. The developed biosensor was applied to the direct determination of 5-HT concentrations in undiluted healthy control and Internet gaming disorder serum samples. The results were verified by comparison with those from liquid chromatography-mass spectrometric analyses. [ABSTRACT FROM AUTHOR]

ZnO:Al films were prepared by magnetron sputtering at room temperature. During the growth process, H radicals produced by radio frequency power sources were in situ introduced into ZnO:Al films. By injecting H radicals, the content of Al in ZnO:Al films increased from 3.4 at. % to 6.1 at. %, which could be ascribed to the reaction between H radicals and ZnO as well as the resputtering of the Zn element. Surface morphologies of ZnO:Al films were tuned from smooth shape to sunflower seed-like. Furthermore, ZnO:Al films without injecting H radicals showed highly c-axis preferential orientation and then nearly became amorphous with the addition of H radicals, which corresponds to the results of Raman spectra. The grain boundary potentials decreased due to the removal of oxygen at grain boundaries and an amount of Vo was produced, which was proved by Raman and x-ray photoelectron spectroscopy results. The optimal resistivity of as-grown ZnO:Al films co-doped with H radicals was 1.5 × 10−3 Ω cm at an H2 ratio of 2.3%. The variation of the carrier concentration for annealed ZnO:Al films at different H2 ratios supported the existence of H interstitials and Vo. The optical bandgap varied from 3.44 eV to 3.71 eV with increasing H radicals. [ABSTRACT FROM AUTHOR]

• Corrosion inhibitor encapsulated nanoemulsion was produced with low energy emulsification method. • Corrosion inhibitor encapsulated in nanoemulsion shows outstanding dispersity in aqueous phase. • Inhibition performances and mechanisms in H 2 S/CO 2 containing 5.0 wt% NaCl solution were studied. Corrosion inhibitor is one of the most economical and effective approaches to protecting metal pipes in the oil and gas industries. However, a great amount of corrosion inhibitors such as imidazoline, are difficult to distribute fast due to their poor solubility or dispersibility in water, which results in inhomogeneous concentration distribution and ineffectiveness. In this study, nano-emulsification technique was developed to improve the dispersity of mercaptoacetic acid-modified oleic imidazoline (MOI) in corrosive water. The formulation of nanoemulsion is optimized with the phase inversion temperature (PIT) and droplet diameter. The prepared nanoemulsion which the hydrophilic lipophilic balance value (HLB) was 11.5 and the loading of corrosion inhibitor was 20 wt% exhibited remarkable water dispersion performance and its mean particle size was less than 100 nm. Moreover, its dispersion performance in water was significantly better than that of the paraffin oil system, and was similar in the ethanol system. The inhibition performances and mechanisms of nanoemulsion for L245 carbon steel in the H 2 S/CO 2 containing 5.0 wt% NaCl solution were investigated with weight loss measurements and electrochemical tests. In terms of inhibition efficiency, the corrosion inhibitor encapsulated in nanoemulsion was exceeding 90%, which was comparable to the system employing ethanol and liquid paraffin as solvents. Further experimental results indicated that the nanoemulsion system was more consistent with the Freundlich adsorption model, unlike the other two systems which followed the Langmuir adsorption model. The morphology and composition of corrosion products were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) methods. The SEM and XPS results demonstrated that the nanoemulsion system did not change the material type of corrosion products, but had a visible influence on their morphology. In addition, the inhibition mechanism was also revealed by theoretical calculations. These findings suggest that nano-emulsification technique has the potential to improve the solubility or dispersibility of oil soluble corrosion inhibitor, thereby expanding its application fields. [ABSTRACT FROM AUTHOR]

Coupling photocatalytic H 2 O 2 evolution with simultaneous furfuryl alcohol oxidation can avoid the slow water oxidation reaction and fully utilize photogenerated carriers to produce valuable chemicals. Herein, a COF (denoted as BTTA) was synthesized by the Schiff-base condensation and in-situ grown on the surface of TiO 2 nanofibers. The resultant TiO 2 /BTTA composite has a large interface and a short carrier migration distance. Furthermore, the porous and ultrathin BTTA layers endow the composites abundant active sites and excellent light absorption ability. Remarkably, a H 2 O 2 -evolution rate of 740 μmol L−1 h−1 and a furoic alcohol conversion of 96 % are achieved. In-situ irradiated X-ray photoelectron spectroscopy and electron spin resonance confirm the S-scheme carrier transfer mechanism, which spatially separates photogenerated carriers with strong redox power. This work opens a new door to the rational design of S-scheme photocatalysts for economic and green photosynthesis of H 2 O 2 and organic compounds. [Display omitted] • The novel TiO 2 /BTTA S-scheme heterojunction photocatalysts were constructed. • TiO 2 /BTTA nanocomposites possess high surface area, abundant active sites and excellent visible light absorption. • S-scheme mechanism and pathways of H 2 O 2 and furoic acid evolution was verified. • The S-scheme heterojunction improved the utilization efficiency of charge and retained great redox capacity. [ABSTRACT FROM AUTHOR]

Differently shaped nickel crystals were obtained at ambient temperature via simple liquid chemical reduction by adding different surfactants (such as polyvinylpyrrolidone (PVP) or cetyltrimethylammonium bromide (CTAB)), with hydrazine hydrate as reducing agent and ethanol as solvent. Nickel nanoparticles (NPs), thorny nickel nanowires or rose‐like nickel crystals were obtained in the synthesis process without any surfactant, with PVP or with CTAB, respectively. The corresponding ruthenium‐on‐Ni crystal supported catalysts (Ru/Ni) were synthesized through galvanic replacement. Their catalytic behavior was tested in the model reaction of the hydrogenation of benzene. The order of their catalytic activity was Ru/thorny Ni nanowire > Ru/rose‐like Ni > Ru/Ni NPs due to different shapes and structures of Ru/Ni. The Ru/thorny Ni nanowires catalyst also exhibited outstanding stability for benzene hydrogenation to cyclohexane. The as‐obtained Ni and Ru/Ni samples were characterized by X‐ray diffraction (XRD), scanning electronic microscopy (SEM), SEM energy dispersive X‐ray spectroscopy (SEM‐EDS), high‐sensitivity low‐energy ion scattering spectroscopy (HS‐LEIS), X‐ray photoelectron spectroscopy (XPS), SEM‐EDS elemental mapping, transmission electron micro‐scope (TEM), and high resolution TEM (HRTEM), to reveal their morphologies, structures and element distribution and further illustrate the intrinsic reasons for their different performance in catalyzing benzene hydrogenation. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Photocatalytic technology was first introduced for seawater uranium extraction. • Uranium could be efficiently extracted from aqueous solution by photocatalytic method under various environmental factors. • U(VI) was reduced to U(IV), existing as UO 2 during photocatalytic process by TiO 2. • The uranium extraction capacity can achieve as high as >3960 mg/g by photocatalytic method. • The extracted uranium could be easily diluted by stirring in air followed by adding Na 2 CO 3 solution. Abstract Uranium extraction from seawater is of significant importance for the sustainable utilization of uranium in the near future; however, several challenges remain owing to the low uranium concentration and high salinity of seawater. In this work, for the first time, photocatalysis by TiO 2 was introduced for U(VI) extraction from seawater. The photocatalysis method achieved a high uranium extraction capacity of 3960 mg/g without saturation. To evaluate the performance of the photocatalysis in the potential real applications, the influence of environmental factors was systematically studied. The results showed that H+ in solution competed with U(VI) ions for the photogenerated e −, inhibiting U(VI) photoreduction. Inversely, U(VI) photoreduction was facilitated at pH > 6.0 and was adequate for U(VI) extraction from seawater. The efficiency of U(VI) photoreduction can also be inhibited by the high initial U(VI) concentration, high salinity, and high TiO 2 dose. Methanol can accelerate U(VI) photoreduction by consuming photogenerated holes. Similarly, humic acid can promote U(VI) photoreduction at acidic conditions, and the reaction efficiency was slightly hindered over pH ∼ 6.5. Although the photoactivity was inhibited to some extent under specific conditions, it was proven that U(VI) could be completely extracted in all systems by increasing the irradiation time. X-ray photoelectron spectroscopy, X-ray diffraction and X-ray absorption near edge structure confirmed that U(VI) was transformed into U(IV) during photocatalysis and that UO 2 was mainly formed on the TiO 2 surface. The extraction of uranium in real seawater is also feasible and the deposited uranium could be easily recovered using a Na 2 CO 3 solution after standing in air for several hours. Therefore, photocatalysis is demonstrated to be an eco-friendly, facile, economical and sustainable approach for uranium extraction from seawater. [ABSTRACT FROM AUTHOR]

By interfacial coupling effect, the reduced graphene oxide (rGO) was constructed on (010) facet of BiVO4, which is a characteristic of the dominant separation of photogenerated electrons. The prepared samples were characterized by X-ray diffractometry and Raman spectra, which indicating that the added rGO plays an important role in regulating of V–O bond. By the X-ray photoelectron spectroscopy, it was found that the valence band value of BGO180 is increased compared with BiVO4, suggesting that there is an effective coupling present between rGO and BiVO4. Under simulated sunlight, the photocatalytic properties of BiVO4/rGO nanocomposite are evaluated by the O2 evolution. The carrier transfer effect between BiVO4 and newly formed coupling layer (BiVO4 and rGO) explains the excellent photoactivity of nanocomposite. [ABSTRACT FROM AUTHOR]

Luminescent metal–organic frameworks (MOFs) have been explored extensively as potential probes for nitroaromatic molecules, which are common constituents of explosive devices. Guest encapsulation within MOF pores is often cited as the prerequisite for emission changes, but the evidence for this signal transduction mechanism is often inadequate. Using the unique bipyridyl ligand AzoAEpP (2,2′-bis[N,N′-(4-pyridyl)ethyl]diaminoazobenzene), we constructed two luminescent pillared paddle-wheel Zn2+ MOFs using aryl dicarboxylate ligands 1,4-naphthalenedicarboxylic acid (ABMOF-1) and benzene 1,4-dicarboxylic acid (ABMOF-2). While both MOFs exhibit luminescence, 2,4-dinitrophenol only extinguishes ABMOF-1 emission. Since the size of the pores in ABMOF-1 precludes guest inclusion, we used X-ray photoelectron spectroscopy (XPS) to confirm the surface interaction and obtain insight into the nature of the quenching process. XPS experiments utilized a fluorinated nitroaromatic molecule, 4-trifluoromethyl-2,6-dinitrophenol, that extinguishes ABMOF-1 emission, and verified surface adsorption through a series of angle-resolved (ARXPS) and argon-ion sputter depth profile experiments. By further developing these techniques, we hope to develop a general approach for distinguishing between the various intermolecular interactions between MOFs and analytes that lead to changes in luminescence. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Supported NiRu bimetallic catalysts with trace Ru were prepared by using NiRuAl-LDHs precursors. • Ru promotes the reduction of Ni2+ in LDHs by hydrogen spillover and significantly decreases the size of Ni metal particles. • NiRu alloy particles are formed during the Ni reduction. • NiRu/Al 2 O 3 bimetallic catalysts exhibit enhanced activity and stability in selective hydrogenation of styrene. Abstract Developing effective nickel-based catalysts in hydrogenation of pyrolysis gasoline (PyGas) is of great importance in chemical industry. Herein, we report a facile fabrication of Al 2 O 3 -supported NiRu bimetallic catalysts, with Ru content ranging from 0.01 wt% to 0.1 wt%, by reducing of precursors of Ni2+Ru3+Al3+-containing layered double hydroxides (NiRuAl-LDHs) in flowing hydrogen. Their catalytic performance was evaluated by styrene hydrogenation, a model reaction in industrial hydrogenation of PyGas (abbreviated as PyGasMF). The LDH precursors initially in situ grow on the surface of microspherical γ -Al 2 O 3 supports. Doping Ru3+ in LDH main layers promotes reduction of Ni2+ by hydrogen spillover and decreases significantly the size of Ni metal particles, and NiRu alloy particles are formed during the reduction. Substitution of an appropriate amount of Ni for Ru enhances the catalytic activity and stability in styrene hydrogenation, demonstrating a synergistic effect of Ni and Ru on hydrogenation reactivity. [ABSTRACT FROM AUTHOR]

Oxidative desulfurization is considered to be one of the promising new methods for super-deep desulfurization of fuel oil. Herein, zinc phthalocyanine/g-C3N4 (g-C3N4/ZnTcPc) composites were synthesized by a facile in situ hydrothermal technique, utilizing g-C3N4, Zn(CH3COO)2 and 1,2,4-benzenetricarboxylic anhydride as the precursors. The crystal structure, morphology and chemical environment of the catalysts were respectively confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Photocatalytic activity of the resulting g-C3N4/ZnTcPc composites was evaluated by desulfurization of thiophene in fuel under visible light with molecular O2 as the oxidant. Compared with pure g-C3N4 and ZnTcPc, g-C3N4/ZnTcPc presented a significantly enhanced photocatalytic activity for the degradation of thiophene in fuel under visible irradiation. Sulfur content of model gasoline (800 ppm) after desulfurization for 90 min was decreased to 125 ppm. The possible preparation pathway of g-C3N4/ZnTcPc has been proposed according to the results of XRD and TEM. The formation mechanism of g-C3N4/ZnTcPc-O2 complex is proposed to be desulfurization by molecular oxygen. [ABSTRACT FROM AUTHOR]

The development of efficient and stable photocatalysts is very important for photocatalytic hydrogen evolution. In this work, a series of CuSe/MnS/Mn 0·5 Cd 0·5 S composites with high hydrogen evolution performance were synthesized by a simple hydrothermal method. The synthesized products were characterized by X-ray diffraction, Scanning electron microscopy, Transmission electron microscopy, Mapping, X-ray photoelectron spectroscopy, UV–Vis diffuse reflection spectroscopy, Mott–Schottky, Transient photocurrent response, Electrochemical impedance spectroscopy, and Photoluminescence spectroscopy. The obtained products showed efficient photocatalytic hydrogen evolution efficiency in Na 2 S–Na 2 SO 3 solution under 300 W Xe lamp (λ ＞ 420 nm), with the highest photocatalytic hydrogen evolution efficiency reaching 24.7 mmol g−1 h−1, which was 4.1 times higher than pure MnS/Mn 0·5 C 0·5 S (5.99 mmol h−1 g−1) and 6.3 times higher than pure CdS (3.59 mmol h−1 g−1). A possible mechanism of photocatalytic hydrogen production was proposed. The addition of CuSe effectively enhances the photogenerated electron-hole separation efficiency and reduces the electron-hole pair complexation rate of CuSe/MnS/Mn 0·5 C 0·5 S composites. This work provides an effective way to improve the photocatalytic activity of Mn 0·5 Cd 0·5 S using transition metal selenide cocatalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

The chemical immobilization of silane on yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) surface is promising in improving both osseointegration and antibacterial activity, however, the effect of low temperature degradation (LTD)-induced the tetragonal (t) to monoclinic (m) phase transformation on the chemical bonding and continuous bioactivity remains unclear. In this study, 3-aminopropyltriethoxysilane (APTES) and 3-mercaptopropyltrimethoxysilane (MPTS) were grafted on the Y-TZP surface. Quantum chemistry revealed that Zr– O –Si bonds formed by t/m -ZrO 2 both had a strong tendency to undergo hydrolysis in acidic or neutral environments, but were stable in alkaline environments. Inductively coupled plasma mass spectrometry showed that the release of Si increased during weeks 1–3 on both APTES- and MPTS-grafted surfaces, then decreased rapidly on MPTS-grafted surface while maintained a sustain release on APTES-grafted surface until week 4; in particular, the hydrolysis of Zr– O –Si bonds did not accelerated by LTD. X-ray photoelectron spectroscopy showed that LTD-induced reductions in Zr– O –Si bond contents on APTES- and MPTS-grafted surfaces were 0.63% and 1.79%, respectively. In vitro MC3T3-E1 cell experiments confirmed that APTES- and MPTS-grafted Y-TZP surfaces maintained similar adhesion and proliferation before and after LTD. Scanning electron microscopy, laser confocal scanning microscopy, and spread plate assay findings showed favorable anti - Porphyromonas gingivalis (P. gingivalis) effects induced by APTES- and MPTS-grafted t/m -ZrO 2 surfaces. Thus, APTES and MPTS both provide LTD-stable and hydrolysis-stable chemical bonding for Y-TZP implants, and t-m phase transformation does not cause detectable effects on Y-TZP bioactivity. [ABSTRACT FROM AUTHOR]

Phosphate is generally considered to be one of the nutrients for plants which may cause eutrophication of the aquatic environment. In this study, a CeO2-functionalized Fe3O4@SiO2 coreshell magnetic nanomaterial (denoted as Fe3O4@SiO2-CeO2) was prepared and used as the adsorbent to remove phosphate from water. The adsorbents were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and N2 adsorption/desorption isotherms. Characterization results show that the particle size is around 8.63 nm, Brunauer-Emmett-Teller (BET) surface area is 179.7 m² · g-1 and the pore volume is 0.39 cm³ · g-1 for magnetite Fe3O4@SiO2-CeO2. The adsorbents could be rapidly separated under an external magnetic field. Batch adsorption tests show that the Fe3O4@SiO2-CeO2 adsorbent exhibited high adsorption affinity for phosphate. Additionally, phosphate adsorption isotherms over the adsorbents could be well described by the Langmuir model, suggesting monolayer adsorption, and phosphate adsorption kinetics followed the pseudo-second-order kinetics. Moreover, increasing pH led to suppressed phosphate adsorption, and phosphate adsorption slightly increased with ionic strength. [ABSTRACT FROM AUTHOR]

ZrO x N y /V 2 O 3 -Y nano-multilayered films with various yttrium additions were deposited on a Si substrate by reactive magnetron sputtering technique. The influences of yttrium addition on the microstructures, strengthening, and toughening characteristics of the nano-multilayered films were examined by the X-Ray diffraction, X-ray photoelectron spectroscopy, electro-probe microanalyzer, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, and nanoindentation instrument. The experimental results showed that the template and modulation layers of the ZrO x N y /V 2 O 3 -Y nano-multilayered films consisted of ZrO 2 , ZrON, ZrN, and V 2 O 3 , Y 2 O 3 , respectively. Under the role of the template layer, the modulation layer maintained the epitaxial growth, which formed a coherent interface structure between the two sublayers as a function of the yttrium addition. When the Y/VO 2 ratio was 1/2, the hardness, elastic modulus, and fracture toughness value could reach 15.1 GPa, 182.2 GPa, and 1.23 MPa m1/2, respectively. The incorporation of yttrium atoms gave rise to the phase transition, and the coherent interface inhibited the dislocation movement during nanoindentation loading, thus contributing to the optimal mechanical behavior of the ZrO x N y /V 2 O 3 -Y nano-multilayered films. [ABSTRACT FROM AUTHOR]

A LaNi 1−x Zn x O 3−δ perovskite structured oxide catalyst is prepared with a one-step citrate complex method and applied as the precursor of the catalyst in ethanol steam reforming (ESR) reaction. The Zn substitution makes the perovskite-oxide difficult to be reduced due to the strong bond of La–O–Zn, which favors the formation of small Ni particle size thus moderates the sintering of nickel. The doping of Zn also effectively suppresses coking in the reaction. The spillover of oxygen and the electron donation effect of Zn species to the surface of metallic nickel is confirmed with an XPS technique. The doping amount shows an optimum value and a LaNi 0.85 Zn 0.15 O 3−δ sample exhibits the highest H 2 product yield and best stability at 700 °C. [ABSTRACT FROM AUTHOR]

In this paper, a series of BiOI/ZnO photocatalysts containing various BiOI contents were prepared by a facile two-step synthetic method. The structure and crystal phase, morphology, surface element analysis, optical property of as-prepared samples are measured by X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV–Vis diffuse reflectance spectrometry (DRS). BiOI/ZnO photocatalytic activities of the prepared photocatalysts were evaluated by photocatalytic degradation of phenol under simulated light irradiation. The phenol degradation rate reached 99.9% within 2 h under simulated solar light irradiation. The probable photocatalytic mechanism of composites photocatalysts is discussed by active species trapping experiments, the surface photovoltage (SPV), the transient photovoltage (TPV) and photoluminescence (PL) measurements. The results manifest that the superior photocatalytic activity of BiOI/ZnO composites is derived from the strong internal electric field between BiOI and ZnO, which is beneficial for the effective separation and transfer of photogenerated charges in ZnO. Moreover, the loading of BiOI on the surface of ZnO inhibited the recombination of photogenerated charge carriers in ZnO, resulting in excellent photocatalytic activity. On the contrary, the effect of an extension of the light absorption range induced by the introduction of BiOI on the phenol degradation activity is not significant. [ABSTRACT FROM AUTHOR]

Poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and poly( N,N′ -dimethyl-(methylmethacryloyl ethyl) ammonium propanesulfonate) (PDMAPS) were grafted on polyurethane (PU) surfaces by one-pot ATRP and click chemistry in order to improve the lubricating and antifouling properties. The successful grafting of PMPC and PDMAPS was confirmed by X-ray photoelectron spectroscopy. The immobilization of zwitterionic polymer brushes significantly improved the surface hydrophilicity and lubricating property of PU. In addition, the protein and bacteria adsorption on the modified PU surfaces were reduced greatly due to the presence of hydrated layer around the zwitterionic groups. The present surface modification approach was simple and versatile for functionalization of polymer surfaces. [ABSTRACT FROM AUTHOR]

Activatable molecular MRI nanoprobe for intracellular GSH sensing was designed. As an alternative to “always on” nanoprobe, activatable imaging nanoprobes which are designed to amplify or boost imaging signals only in response to the targets have attracted more and more attention. In this paper, we designed a novel activatable molecular magnetic resonance imaging (MRI) nanoprobe for tumor cell recognization based on a MRI signal variation induced by the distance change between T 1 and T 2 contrast agents (CAs) in the presence of glutathione (GSH). To achieve this aim, carboxyl group functionalized iron oxide nanoparticles (Fe 3 O 4 NPs) and polyethylene glycol-coated gadolinium oxide (PEG-Gd 2 O 3 ) NPs as T 2 and T 1 MRI CA were connected by cystamine which contains a disulfide linkage. Transmission electron microscopic (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive spectrometer (EDS), fourier transform infrared spectroscopy (FT-IR), mass spectra and 1 H nuclear magnetic resonance spectroscopy ( 1 H NMR) were introduced for their characterizations. The formation of Fe 3 O 4 -cystamine-Gd 2 O 3 (Fe 3 O 4 -SS-Gd 2 O 3 ) nanocomplex resulted in a quenched T 1 signal due to the near proximity of PEG-Gd 2 O 3 NPs to Fe 3 O 4 NPs and a “light-up” T 1 signal with the cleavage of disulfide bond in the presence of GSH. These results provide not only an easy way to realize MRI of tumor cells based on the overexpressed intracellular GSH level, but also a new insight for the design of activatable MRI nanoprobe. [ABSTRACT FROM AUTHOR]

Crosslinked hydrogel brushes were grafted from stainless steel (SS) surfaces for marine antifouling. The brushes were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) respectively with different fractions of crosslinker in the feed. The grafted layers prepared with different thickness were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometry and water contact angle measurements. With the increase in the fraction of crosslinker in the feed, the thickness of the grafted layer increased and the surface became smooth. All the brush-coated SS surfaces could effectively reduce the adhesion of bacteria and microalgae and settlement of barnacle cyprids, as compared to the pristine SS surface. The antifouling efficacy of the PEGMA polymer (PPEGMA)-grafted surface was higher than that of the MPC polymer (PMPC)-grafted surfaces. Furthermore, the crosslinked hydrogel brush-grafted surfaces exhibited better fouling resistance than the non-crosslinked polymer brush-grafted surfaces, and the antifouling efficacy increased with the crosslinking density. These hydrogel coatings of low toxicity and excellent anti-adhesive characteristics suggested their useful applications as environmentally friendly antifouling coatings. [ABSTRACT FROM AUTHOR]

The bifunctional catalysts which can improve both oxygen evolution (OER) and oxygen reduction reaction (ORR) activity are highly desirable for fuel cells, metal-air batteries and water splitting. Here, we report a perovskite structure Sr 0.9 M 0.1 RuO 3-δ (SMRO, M=K, Na, Ag) synthesized via sol-gel method performing excellent bifunctional catalytic activity. With the metal ion (M+) doping in A-site, X-ray photoelectron spectroscopy analysis reveals that oxygen vacancy and lattice oxygen are introduced into the structure, which is confirmed as the primary reason for the improvement of catalytic activity. The highest OER and ORR activity among these four samples is observed in Sr 0.9 Ag 0.1 RuO 3 (SARO). This work may shed light on the designing of high-efficiency bifunctional OER/ORR electrocatalysts. • With the metal ion (M+) doping in A-site, XPS analysis reveals that oxygen vacancy and lattice oxygen are introduced into the perovskite structure, leading to the OER/ORR activity improved efficiently. • Sr 0.9 Ag 0.1 RuO 3 (SARO) performs the highest bifunctional OER and ORR activity among the four samples investigated in this paper. • The high catalytic activity in SARO can retain at least 8 hours for OER and 2000 potential cycles for ORR in long-term stability tests. [ABSTRACT FROM AUTHOR]

The reduction of hexavalent chromium combined with the process of dissimilatory iron reduction is an important strategy for microbial remediation of chromium-contaminated soil. However, its applicability is limited by the slow speed of bacterial bioreduction and the toxic effect of heavy metals on bacteria. Here, biochar (BC) was used as a substrate and was loaded with iron oxide in the form of hematite and Shewanella loihica to synthesize a BC@α-Fe 2 O 3 @ S. loihica complex and thus achieve combined microbial–chemical remediation. After optimization by a Box–Behnken design, the optimal dosages of the complex, humic acid (as an electron shuttle), and sodium lactate (as an electron donor) were found to be 1.38 mL/g, 33.94 mg/g, and 12.95%, respectively. The Cr(VI) reduction rate in soil contaminated with 1000 mg/kg Cr(VI) reached 98.26%, and remediation could be achieved within 7 days. Characterization of the BC@α-Fe 2 O 3 @ S. loihica complex before and after it was used for remediation by energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy proved that the oxygen-containing functional groups and aromatic compounds on the surface of the BC participated in the adsorption and reduction of Cr(VI) and that the loaded hematite particles were fully utilized by microorganisms. Therefore, the BC@α-Fe 2 O 3 @ S. loihica complex has great potential for the remediation of Cr(VI)-contaminated soil. [Display omitted] • The BC@α-Fe 2 O 3 @ loihica can make the 1000 mg/kg Cr (VI) reduction rate reach 98.26% within 7 days. • Iron oxide and electron shuttle have obvious synergistic enhancement in biological reduction. • Complex restoration can reduce soil biological toxicity and improve soil community structure. [ABSTRACT FROM AUTHOR]

This research is aimed to improve the poor electron conductivity of CeO as the catalyst support for methanol oxidation. Pt/CeO catalyst coated with nitrogen-doped carbon layer has been prepared through a combined microwave-assisted polyol with in-situ carbonization of nitrogen-doped carbon-coating process using polyvinylpyrrolidone as the nitrogen-doped carbon precursor. Electrochemical results show that Pt/CeO catalyst coated with nitrogen-doped carbon layer has higher activity than the uncoated Pt/CeO catalyst due to more uniform dispersion, electron-donating effects, and the superior electrical conductivity of the CeO support enhanced by the nitrogen-doped carbon layer. Further, electrochemical results show that the optimal doped amount of polyvinylpyrrolidone is 20 wt%. The physical characteristics such as high-resolution transmission electron microscopy and X-ray photoelectron spectrometer have confirmed the existence of the nitrogen-doped carbon layer on CeO. Graphical Abstract: A novel Pt/CeO catalyst coated with N-doped carbon layer has been successfully prepared through a combined microwave-assisted polyol with in-situ carbonization of N-doped carbon-coating process using polyvinylpyrrolidone (PVP) as the N-doped carbon precursor. The greatly improved activity and durability of Pt/CeO@C-N catalyst is mainly a consequence of more uniform dispersion, smaller size of Pt nanoparticles, and the superior electrical conductivity of the CeO support enhanced by the N-doped carbon layer.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Several methods and materials have been explored for the sensitive and practicable detection of polycyclic aromatic hydrocarbons (PAHs). However, it is still a challenge to develop simple and cost-effective sensing techniques for PAHs. Herein we report the synthesis and construction of Fe 3 O 4 @Au SERS substrate. This magnetic substrate was composed by Fe 3 O 4 microspheres and Au NPs. The size, morphology, and surface composition of Fe 3 O 4 @Au were characterized by multiple complimentary techniques including scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray powder diffraction. The spatial distributions of electro-magnetic field enhancement around Fe 3 O 4 @Au was calculated using finite difference time domain (FDTD) simulations. As a result of its remarkable sensitivity, the Fe 3 O 4 @Au-based SERS assay has been applied to detect the 16 EPA priority PAHs. The LODs achieved by our method (100–5 nM, 16.6–1.01 μg L −1 ) make it promising for the rapid screening of highly contaminated cases. As a proof-of-concept study, the substrate was applied in SERS sensing of PAHs in river matrix. The 16 PAHs could be differentiated based upon their characteristic SERS peaks. Most importantly, the detection was successfully conducted using a portable Raman spectrometer, which could be used for on-site monitoring of PAHs. [ABSTRACT FROM AUTHOR]

A novel polyethylenimine-functionalized ion-imprinted hydrogel (Cu(II)- p (PEI/HEA)) was newly synthesized by 60 Co-γ-induced polymerization for the selective removal of Cu(II) from aqueous solution. The adsorption performances including the adsorption capacity and selectivity of the novel hydrogel were much better than those of similar adsorbents reported. The hydrogel was characterized via scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectra, thermal gravimetric analysis and X-ray photoelectron spectroscopy to determine the structure and mechanisms. The adsorption process was pH and temperature sensitive, better fitted to pseudo-second-order equation, and was Langmuir monolayer adsorption. The maximum adsorption capacity for Cu(II) was 40.00 mg/g. The selectivity coefficients of ion-imprinted hydrogel for Cu(II)/Pb(II), Cu(II)/Cd(II) and Cu(II)/Ni(II) were 55.09, 107.47 and 63.12, respectively, which were 3.93, 4.25 and 3.53 times greater than those of non-imprinted hydrogel, respectively. Moreover, the adsorption capacity of Cu(II)- p (PEI/HEA) could still keep more than 85% after four adsorption–desorption cycles. Because of such enhanced selective removal performance and excellent regeneration property, Cu(II)- p (PEI/HEA) is a promising adsorbent for the selective removal of copper ions from wastewater. [ABSTRACT FROM AUTHOR]

In the current study, in situ free radical polymerization was employed to prepare Cu-imprinted composite hydrogel (Cu-ICH). The cross-sectional morphology of the Cu-ICH evaluated by scanning electron microscopy indicated that the copper-loaded Cu-ICH became rougher and the pore size of the gel became smaller compared to the unloaded Cu-ICH. The ability of the Cu-ICH to adsorb Cu from aqueous solutions was assessed using batch adsorption technique. The adsorption capacity increased with the initial concentration of Cu, but decreased as the temperature rose from 298 to 318 K. Thermodynamic parameters such as Gibbs free energy (Δ G), enthalpy (Δ H), and entropy (Δ S) for the Cu adsorption were evaluated. It was suggested that the adsorption process was a spontaneous, exothermic process that had positive entropy. Selectivity study indicated that ion imprinting technique resulted in excellent affinity of the Cu-ICH toward Cu. Finally, the adsorption mechanism was studied by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The results indicated that copper adsorption was mainly through interactions with the amine and carbonyl groups. [ABSTRACT FROM AUTHOR]

Thermo-sensitive microgels known as PMO-MGs were synthesized via surfactant free emulsion polymerization, with poly(ethylene glycol) methacrylate (OEGMA475) and 2-(2-methoxyethoxy) ethyl methacrylate (MEO2MA) used as the monomers and N, N-methylene-bis-acrylamide used as the crosslinker. PMO-MGs are spherical in shape and have an average diameter of 323 ± 12 nm, as determined via transmission electron microscopy. PMO-MGs/poly (ether sulfone) (PES) composited ultrafiltration membranes were then successfully prepared via the non-solvent-induced phase separation (NIPS) method using a PMO-MG and PES mixed solution as the casting solution. The obtained membranes were systematically characterized via combined X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy and contact angle goniometer techniques. It was found that the presence of PMO-MGs significantly improved the surface hydrophilicity and antifouling performance of the obtained membranes and the PMO-MGs mainly located on the channel surface of the membranes. At 20 °C, the pure water flux increased from 217.6 L·m−2·h−1 for pure PES membrane (M00) to 369.7 L·m−2·h−1 for PMO-MGs/PES composited membrane (M20) fabricated using the casting solution with 20-weight by percentage microgels. The incorporation of PMO-MGs also gave the composited membranes a thermo-sensitive character. When the temperature increased from 20 to 45 °C, the pure water flux of M20 membrane was enhanced from 369.7 to 618.7 L·m−2·h−1. [ABSTRACT FROM AUTHOR]

Microcomposite particles of aluminum (Al) dotted by ammonium dinitramide (ADN) (Al@ADN) are successfully prepared by an in-situ crystallization growth method. The morphologies, structures and thermal behavior of Al@ADN are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and simultaneous thermogravimetry and differential scanning calorimetry. The compositions and morphologies of Al@ADN after heating are characterized by X-ray photoelectron spectroscopy (XPS) and SEM. A high-speed camera is used to record the combustion performances of Al@ADN in a transparent quartz tube. Furthermore, the morphologies and structures of the residues are analyzed by SEM and XRD. The results show that ADN is deposited on the surface of Al to form Al@ADN. The decomposition of ADN increases the total oxidation degree of the Al particles. Under heating, the acids decomposed by ADN corrode the surficial alumina layer and the internal aluminum react with HNO 3 to form Al(NO 3) 3 , which makes the combustion of Al easier. Under an oxygen atmosphere, the pure Al could not be ignited. In contrast, Al@ADN could be ignited and Al@ADN 5:1 has a shorter ignition and burning time compared with Al@ADN 10:1. After burning, the Al@ADN composites are completely converted to α- and γ-Al 2 O 3. For Al@ADN 10:1, the residues show a cube-like stacking, while a ribbon-like stacking is presented for Al@ADN 5:1. [Display omitted] • Core-shell energy storage materials of aluminum dotted by ammonium dinitramide. • Shorter ignition time and burning time with increasing ammonium dinitramide. • Thermal oxidation interaction mechanism of aluminum and ammonium dinitramide. • Aluminum shells are corroded by decomposition of ammonium dinitramide to form Al(NO 3) 3. • Morphologies and structures after aluminum combustion. [ABSTRACT FROM AUTHOR]

A hybrid nanocomposite based on cobalt phthalocyanine (CoPc) immobilized on nitrogen-doped graphene (N-G) (N-G/CoPc) has been developed to modify glassy carbon electrode (GCE) for the sensitive detection of thiols. The nanocomposites were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Cyclic voltammetric studies showed that cobalt phthalocyanine and nitrogen doped graphene have a synergic effect and significantly enhance the electrocatalytic activity of the modified electrode towards thiols oxidation compared with electrodes modified with solely CoPc or N-G. The electrochemical oxidation responses were studied and the reaction mechanisms were discussed. The sensors exhibited a wide linear response range from 1 μΜ to 16 mM and a low detection limit of 1 μΜ for the determination of l -cysteine, reduced l -glutathione and 2-mercaptoethanesulfonic acid in alkaline aqueous solution. The proposed N-G/CoPc hybrids contribute to the construction of rapid, convenient and low-cost electrochemical sensors for sensitive detection of thiols. [ABSTRACT FROM AUTHOR]

Abstract: Sensitive determination of carcinoembryonic antigen (CEA) is very important in clinical research and diagnosis. Herein we report the design and synthesis of a new kind of immunosensor based on the benefits of hyperbranched structure. The hyperbranched polyester was grafted to the surface of indium tin oxides glass (ITO) electrode, and the grafting processes were characterized by attentuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). After CEA and horse radish peroxidase (HRP)-labeled antibody-conjugated AuNPs (HRP–Ab2–AuNPs) bioconjugates were immobilized on the surface of the hyperbranched structure-modified electrode, the optimized conditions of the above electrode were investigated. Moreover, the analytical performance of the proposed immunosensor showed a high sensitivity, a linear range from 0.01 to 80ng/mL with a low detection limit of 2.36pg/mL, and good selectivity for CEA. The designed immunoassay system holds great potential for ultrasensitive electrochemical biosensing of other analytes. [Copyright &y& Elsevier]

Triethylamine, as a typical gas of volatile organic compounds, is a growing threat to human health due to its extensive applications in industry. In this study, ZIF-8 derived ZnO polyhedrons are decorated by CsPbBr 3 quantum dots via electrostatic adsorption. Then a highly sensitive sensor towards triethylamine based on ZnO-CsPbBr 3 composite is successfully fabricated. Compared with sensors based on pristine ZnO and ZnO (nanoparticles)-CsPbBr 3 , ZnO-CsPbBr 3 displays a higher response value (~ 60 towards 100 ppm of TEA), shorter response/recovery time (2/18 s), and lower detection limit (5 ppb). Thus, highly-sensitive detection and efficiently-catalytic oxidation of trimethylamine can be achieved. Such distinguished performance can be ascribed to its unique architecture and n-n heterojunction. Notably, the sensing mechanism is thoroughly interpreted by X-ray photoelectron spectroscopy, temperature programmed desorption of O 2 and in-situ diffuse scattering Fourier transform infrared spectra. • ZIF-8 derived ZnO-CsPbBr 3 polyhedrons are employed as a triethylamine sensor. • Prominently, its response time is 2 s and the detection limit is 5 ppb. • The vinylamine intermediate is firstly confirmed by DRIFT. • Such distinguished performance is closely related to n-n heterojunction. [ABSTRACT FROM AUTHOR]

Copper (II) complexes containing mixed ligands were synthesized in dimethyl formamide (DMF). The intense cyan emission at an ambient temperature is observed for solid copper (II) complexes with salicylic acid and a 12% quantum yield with a fluorescent lifetime of approximately 10 ms. Hence, copper (II) complexes with salicylic acid are excellent candidates for photoactive materials. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) reveal that the divalent copper metal centers coordinate with the nitrogen and oxygen lone pairs of conjugate ligands. XPS binding energy trends for core electrons in lower-lying orbitals are similar for all three copper (II) complexes: nitrogen 1s and oxygen 1s binding energies increase relative to those for undiluted ligands, and copper 2p3/2 binding energies decrease relative to that for CuCl2. The thermal behavior of these copper complexes reveals that the thermal stability is characterized by the following pattern: Cu(1,10-phenanthroline)(salicylic acid) > Cu(1,10-phenanthroline)(2,2'-bipyridine) > Cu(1,10-phenanthroline)(1-benzylimidazole)2. [ABSTRACT FROM AUTHOR]

High temperature and oxidation are two of the most critical factors that cause epoxy asphalt aging. This paper aims to clarify the variation of mechanical performance and structure of effect of cold-mixed epoxy asphalt (CEA) after thermal-oxidative (TO) aging. The mechanical properties of CEA were studied by tensile tests and dynamic mechanical analysis. The microstructure of CEA was studied by Fourier transform infrared spectrum, X-ray photoelectron spectroscopy, SEM, and fluorescence microscopy. The results indicated that the tensile strength of CEA increased to 5.16 MPa, the elongation at break decreased to 50.3%, and the T g decreased significantly after TO aging. TO aging made the epoxy resin in CEA post-cure, oxidate, degrade and the cross-linked network break. Furthermore, the asphalt particles in CEA agglomerated and oxidized. [Display omitted] • ER underwent a post-curing reaction and degradation. • Asphalt underwent volatilization of the light components and an oxidation reaction. • Thermal-oxidative aging destroyed the original phase structure of the CEA. [ABSTRACT FROM AUTHOR]

[Display omitted] • A fast reduction of U6+ to U4+ occurs on semiconductors during XPS measurement. • Slower breakage of uranyl occurs on non-semiconductors under X-ray irradiation. • XPS measurement could change the elements state even if far from the center of beam. • Measures are proposed to reduce the beam induced effects in XPS measurement. X-ray photoelectron spectroscopy (XPS) is an efficient technique for recognizing the state of elements. However, the effects of X-ray irradiation on change in the chemical state are sometimes ignored, which may impair the understanding of the environmental behavior of these elements. This study determined the change in the U 4f spectra induced by X-ray irradiation during XPS detection. For U(VI) on non-semiconductors, X-ray irradiation led to a negative shift of U 4f 7/2 to ∼ 380.8 eV due to the break of the uranyl molecules, but not resulting in U(IV) species. However, owing to the photocatalytic reduction of U(VI), the irradiation of U(VI) loaded semiconductors rapidly induced the negative shift of U 4f 7/2 peak to ∼ 379.8 eV, which is the characteristic of U(IV). Moreover, apparent photo-reduction occurred even if the samples were far from the center of the X-ray beam (>3971 μm). Based on these findings, methods for reducing potential error due to X-ray irradiation are suggested, including using the minimum scan time, measuring uranium-containing samples first or independent of other samples, and using X-ray of lower intensity. The results indicated that X-ray induced alteration to the chemical states must be considered when using X-ray techniques. [ABSTRACT FROM AUTHOR]

A highly selective fluorescence sensor based on boron and nitrogen co-doped carbon quantum dots (BN-CDs) was firstly constructed for the determination of 1,1-diamino-2,2-dinitroethylene (FOX-7). The BN-CDs fluorescent probe was prepared by a simple, green, and low-cost one-pot hydrothermal carbonization method. The BN-CDs with good dispersion had strong fluorescence property, and the particle size was about 3 nm. The Fourier transform infrared spectrum and X-ray photoelectron spectroscopy showed that B and N elements were successfully co-doped into CDs. Under the optimal experiment condition, BN-CDs fluorescent probe had a good linear relationship with the concentrations of FOX-7 in the range of 0–80 μM, and the limit of detection was 0.41 μM. The fluorescence of BN-CDs decreased with the increase of FOX-7 concentration, which was ascribed to inner filter effect. The fluorescent sensor has high sensitivity and good selectivity, which can be successfully applied in actual water samples with satisfactory recovery. • The fluorescent probes were proposed with BN-CDs based on inner filter effect. • BN-CDs were used as fluorescent probes to detect FOX-7. • The quenching mechanism was studied systematically. [ABSTRACT FROM AUTHOR]

The effects of carbon nanotubes (CNTs) on the mechanical and fracture properties of ramie fiber-reinforced epoxy composites were investigated. Three-point bending, short beam shear, single-edge-notch bending, and Charpy impact tests were employed to evaluate the properties of ramie fiber-reinforced composites without and with CNTs modification. The fracture mechanisms were revealed with the aid of the dynamic mechanical analysis, Fourier transform infrared, and X-ray photoelectron spectroscopy. It was found that the mechanical and fracture properties of ramie fiber-reinforced composites were enhanced by incorporating multiwalled carbon nanotubes, except the impact fracture toughness. The unique chemical compositions and the multiscaled nanosized microstructures of natural fibers brought into focus new mechanisms for the improvement of the mechanical properties of natural fiber-reinforced composites. [ABSTRACT FROM AUTHOR]

A series of novellanthanide-containing peroxo-isopolyoxomolybdates,Na2(NH4)3[H3Ln6(H2O)26(MoO4){Mo7O22(O2)2}4]·nH2O [n= 24; Ln = CeIII(1), PrIII(2), SmIII(3), EuIII(4); n=25; Ln = NdIII(5)] and Na4(NH4)3[H4La5(H2O)21(MoO4){Mo7O22(O2)2}4]·17H2O (6) have successfully been synthesized by the conventional method andfurther characterized by elemental analyses, X-ray photoelectron spectroscopy,X-ray powder diffraction, IR and UV spectra, thermogravimetric analyses,and single-crystal X-ray diffraction. All of the six compounds arecomposed of the [Ln4(H2O)16(MoO4){Mo7O22(O2)2}4]14–polyoxoanion. 1–5can further generate two-dimensional structures throughLnIIIcations, whereas 6shows the one-dimensionalchain structure linked by LaIIIcations. These compoundsrepresent the first examples of introducing peroxo groups into thelanthanide-containing isopolyoxomolybdates. 1is selectedas an example to investigate the electrochemical behavior of thesecompounds. In addition, the fluorescence analyses of 3and 4have been studied. The spectra exhibit obviousfluorescence signals of SmIIIand EuIIIcations. [ABSTRACT FROM AUTHOR]

Abstract: Monodisperse CeO2 hollow nanoparticles were synthesized by a template-free hydrothermal method. The average size of the nanoparticles was measured to be 75nm. Detailed experiments revealed that the CeO2 hollow nanoparticles were formed directly by oriented attachment of the initial CeO2 nanocrystals. Although Cu2+ was introduced into the system, the final CeO2 product was free of Cu species, which was confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectrum (XPS) studies. Furthermore, the as-prepared CeO2 hollow nanoparticles revealed superior catalytic activity toward CO oxidation compared to commercial CeO2 fine powders. It may provide a new path for the fabrication of inorganic hollow structures upon introducing alien metal ions. [Copyright &y& Elsevier]

Abstract: Chromite ore processing residue (COPR) poses a great environmental and health risk with persistent Cr(VI) leaching. To reduce Cr(VI) and subsequently immobilize in the solid matrix, COPR was incubated with nanoscale zero-valent iron (nZVI) and the Cr(VI) speciation and leachability were studied. Multiple complementary analysis methods including leaching tests, X-ray powder diffraction, X-ray absorption near edge structure (XANES) spectroscopy, and X-ray photoelectron spectroscopy (XPS) were employed to investigate the immobilization mechanism. Geochemical PHREEQC model calculation agreed well with our acid neutralizing capacity experimental results and confirmed that when pH was lowered from 11.7 to 7.0, leachate Cr(VI) concentrations were in the range 358–445mgL−1 which contributed over 90% of dissolved Cr from COPR. Results of alkaline digestion, XANES, and XPS demonstrated that incubation COPR with nZVI under water content higher than 27% could result in a nearly complete Cr(VI) reduction in solids and less than 0.1mgL−1 Cr(VI) in the TCLP leachate. The results indicated that remediation approaches using nZVI to reduce Cr(VI) in COPR should be successful with sufficient water content to facilitate electron transfer from nZVI to COPR. [Copyright &y& Elsevier]

Abstract: A visible light active photocatalyst was prepared through boron-doping by using sodium borohydride as boron source. Different from the previous boron-doped titania prepared at high temperature, our preparation was carried out at 55°C under hydrothermal condition. The as-prepared boron-doped titania was characterized by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, Raman spectroscope, diffuse reflection spectra and N2 adsorption–desorption measurements. The results showed that diboron trioxide phase appeared in the X-ray diffraction pattern of such photocatalyst. Compared to boron-doped titania synthesized by sol–gel method and pure TiO2, this novel photocatalyst exhibited stronger absorption in the visible region, and it also showed larger surface area. The photocatalytic activity was evaluated for degradation of Reactive Brilliant Red (C.I. Reactive Red 2) and 4-chlorophenol under visible light irradiation, respectively. The trend of photocatalytic activity was as follows: boron-doped titania (hydrothermal method)>boron-doped titania (sol–gel method)>pure titania>Degussa P25. [Copyright &y& Elsevier]

N-doped titania hollow spheres were prepared using hydrothermally prepared carbon spheres as template. The prepared hollow spheres were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectrum (DRS). The photocatalytic activity of as-prepared hollow titania spheres was determined by degradation of Reactive Brilliant Red dye X-3B (C.I. reactive red 2) under visible light irradiation, and was compared to commercial P25 titania. It was revealed that the photocatalytic activity of the titania hollow spheres enhanced a lot. The apparent rate constant of the titania hollow spheres was almost 17 times as that of P25 titania. [Copyright &y& Elsevier]