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The composite microgels were synthesized from N‐Isopropylacrylamide (NIPAM) and acrylic acid (AA) monomers in the presence of graphene oxide (GO) using an in situ radical copolymerization method. The successful preparation of these composite microgels was investigated through Fourier transform infrared spectroscopy (FTIR), ultraviolet visible absorption spectroscopy (UV–vis), and Raman spectroscopy. Due to the hydrophilic properties of GO and the microgels containing oxygenated groups (OH, COOH, and CONH2), quartz crystal microbalance (QCM) sensors can be fabricated by spraying the GO/P(NIPAM‐co‐AA) dispersion onto QCM sensors as sensitive coating materials. The results indicate a notable enhancement in the performance of GO/P(NIPAM‐co‐AA) modified QCM humidity sensor, compared to QCM sensors modified with either GO or P(NIPAM‐co‐AA) microgels alone. This improvement is mainly evidenced by higher sensitivity and reduced moisture hysteresis. The humidity sensing mechanism is based on the combined effect of GO and P(NIPAM‐co‐AA) microgels, which synergistically enhance the sensor's performance. Additionally, the results from water contact angle measurements, laser scanning confocal microscopy (LSCM), and scanning electron microscope (SEM) show that GO/P(NIPAM‐co‐AA) exhibits greater roughness and stronger hydrophilicity than either GO or P(NIPAM‐co‐AA) microgels alone. These properties make GO/P(NIPAM‐co‐AA) an effective moisture‐sensitive material for QCM sensors. [ABSTRACT FROM AUTHOR]

The rapid development of the battery industry has brought about a large amount of waste battery pollution. How to realize the high-value utilization of waste batteries is an urgent problem to be solved. Herein, cobalt and titanium compounds (LTCO) were firstly recovered from spent lithium-ion batteries (LIBs) using the carbon thermal reduction approach, and plasmonic attapulgite/Co(Ti)Ox (H-ATP/Co(Ti)Ox) nanocomposites were prepared by the microwave hydrothermal technique. H-ATP had a large specific surface area and enough active sites to capture CO2 molecules. The biochar not only reduced the spinel phase of waste LIBs into metal oxides including Co3O4 and TiO2 but also increased the separation and transmission of the carriers, thereby accelerating the adsorption and reduction of CO2. In addition, H-ATP/Co(Ti)Ox exhibited a localized surface plasmon resonance effect (LSPR) in the visible to near-infrared region and released high-energy hot electrons, enhancing the surface temperature of the catalyst and further improving the catalytic reduction of CO2 with a high CO yield of 14.7 μmol·g−1·h−1. The current work demonstrates the potential for CO2 reduction by taking advantage of natural mineral and spent batteries. [ABSTRACT FROM AUTHOR]

Due to its excellent mechanical and thermodynamic stability, Cr5SiB2 is considered as a potential high-temperature ceramic candidate. However, the effect of high pressure on the structural stability and related properties of Cr5SiB2 cannot be unknown. In this paper, we apply first-principles calculations to explore the effect of pressures on the structural stability, mechanical properties, and thermodynamics of Cr5SiB2. The results show that Cr5SiB2 has thermodynamic, mechanical and dynamics stability under 0–50GPa. Note that Cr5SiB2 will transition from brittle-to-ductile around 30GPa. The anisotropy in elastic of Cr5SiB2 was characterized by three-dimensional (3D) surface constructions and three-dimensional (2D) planar projections. In addition, it is found that the melting point and thermal conductivity of Cr5SiB2 increase with increasing the pressure. Finally, the thermodynamic properties were discussed. [ABSTRACT FROM AUTHOR]

A two-dimensional layered CeO2/Bi2O3 composite was synthesized by microwave solvothermal method. X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), UV-Vis diffuse reflection spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS) were used to studied crystal structure, morphology, optical performance, elemental composition and the surface electronic state of the samples. The photocatalytic properties of the prepared samples were evaluated by photocatalytic desulfurization under visible light. When the molar ratio of Ce and Bi was 1:2, CeO2/Bi2O3 composite presented the highest photocatalytic desulfurization rate. Transient Photocurrent measurement, electrochemical impedance spectroscopy (EIS) and photoluminescence spectroscopy (PL) showed that CeO2 and Bi2O3 formed a heterojunction, which could promote the separation of photogenerated electrons and holes, improving the photocatalytic activity. Furthermore, it was found that the active species of hydroxyl radical (·OH) played an important role in the photocatalytic degradation of dibenzothiophene (DBT) based on the active species capture experiment. Finally, a plausible mechanism for the photocatalytic oxidative desulfurization of this nanocomposite was proposed. [ABSTRACT FROM AUTHOR]

The development of efficient heterojunction photocatalysts with a facilitated charge carrier separation rate and improved light-harvesting capacity is still a challenging issue for effectively solving environmental pollution. Herein, a one-step refluxing process was employed to construct 2D/2D CdIn2S4/In2S3 (CISI) heterojunction photocatalysts with an intimate interface between these two components. The crystal structure, morphology, light-harvesting capacity, and Cr(VI) photoreduction performance were systematically investigated and discussed in detail. The tight interface formed between CdIn2S4 (CIS) and In2S3 (IS) could effectively facilitate the charge carrier separation and transfer. Thus, the resulting CISI composites exhibited a high efficiency for Cr(VI) photoreduction under visible light, with the optimal sample of 0.5 CISI. The charge transfer kinetics were deeply investigated by multiple techniques. Based on the characterization results, a possible mechanism for Cr(VI) photoreduction was proposed. [ABSTRACT FROM AUTHOR]

The existence of an HCP phase in FCC-type high-entropy alloys can improve the alloy's mechanical properties. In many cases, an HCP phase is induced by deformation. In the present work, an FCC to HCP transition was detected during the cooling of Co1.5CrFeMnNi0.5 and Co1.75CrFeMnNi0.25 alloys. Therefore, arc-melted annealed CoxCrFeMnNi2−x (x = 0.25–1.75) alloys that were then subjected to long-term vacuuming were investigated using XRD, DSC, HT-XRD, thermodynamic calculation, and first-principle calculation. It was confirmed that the FCC to HCP transition occurred at ~450 °C during the cooling of the alloys with x ≥ 1.5. The volume fraction of the HCP phase increased with Co content. It was proven that the HCP phase was not stable above 600 °C. First-principle calculations further indicated that the HCP structure was more stable than the FCC structure for Co1.75CrFeMnNi0.25 alloy, and there was a likelihood of an FCC to HCP transition. Moreover, experimental tests confirmed that the microhardness of the Co1.75CrFeMnNi0.25 alloy reached 213 HV because it contained a substantial HCP phase. This value is much higher than those of other non-HCP-containing alloys, either in their as-cast states or after annealing. These results provide guidance for the design of FCC-type high-entropy alloys with desirable mechanical properties through HCP phase strengthening. [ABSTRACT FROM AUTHOR]

Carbon quantum dots (CQDs)/attapulgite (ATP) nanocomposite was prepared by a simple impregnation method. The ATP was initially modified with hydrochloric acid solution, which favored for the combination of CQDs due to the generation of hydroxyl group on the surface. XRD shows the decrease of interplanar spacing of ATP (1 1 0) plane, suggesting that the CQDs are immobilized on the surface of ATP. UV–Vis shows that the absorption peak of modified ATP is apparently red-shifted and the absorbance intensity of CQDs/ATP is higher than others. FT-IR and XPS show that the CQDs are immobilized on the surface of ATP through hydroxylation reaction. TEM shows that the average diameter of CQDs nanoparticles is about 5 nm and they are coated on the surface of ATP uniformly. The CQDs/ATP nanocomposite was employed as catalyst for photocatalytic degradation of dibenzothiophene (DBT) in model gasoline under visible light irradiation. The influence of the mass ratio of CQDs to ATP on desulfurization performance was investigated. The desulfurization rate of DBT could reach 93% when the mass ratio of CQDs/ATP is 3:10. The enhanced photocatalytic oxidative desulfurization was attributed to the sensitizing effect and up-conversion property of CQDs. [ABSTRACT FROM AUTHOR]

The Al-12.6Si eutectic alloy has been modified via the Al-5Ti master alloy to improve both microstructure and mechanical properties. The results show that the fraction of the primary α-Al phase in the Al-12.6Si alloy and the mechanical properties of the resulting alloy vary considerably after modification with the Al-5Ti master alloy at different temperatures. With increasing modification temperature, the fraction of primary α-Al in the Al-12.6Si alloy increases, varying with the amount of added Al-5Ti. For an added amount of 0.2 wt.% Al-5Ti, the fraction of primary α-Al in the Al-12.6Si alloy reaches a maximum. The tensile strength and elongation of an Al-12.6Si alloy modified with 0.2 wt.% Al-5Ti at different temperatures evidently increase compare with unmodified alloys. [ABSTRACT FROM AUTHOR]

Water splitting based on heterogeneous photocatalytic nanomaterials is an attractive approach for generating hydrogen as a clean chemical fuel from solar energy. However, the high defect-induced recombination rate of photoexcited electron–hole pairs and poor photostability have greatly limited the heterophotocatalysts’ practical application. Herein, we used a biotemplate method to give reduced graphene oxide (RGO) a remarkable unique bio-porous morphology with significant anti-aggregation of CeO2 square quantum dots (SQDs) when growing them in situ during a simple hydrothermal process. Biomorphic CeO2 SQDs–RGO has higher electrical conductivity and a narrowed band gap due to there being abundant oxygen vacancies, which results in more effective photo-induced charge generation, transfer and separation. The composite is able to act as an active visible light photocatalyst for highly efficient hydrogen generation applications. Such biomimetic designs could inspire immense research in synthesizing materials with a controlled structure and morphology toward achieving novel graphene-based nanocomposite photocatalysts for solar energy conversion. [ABSTRACT FROM AUTHOR]

In order to obtain the biological active compound, α-mangostin, from the traditional native mangosteen (Garcinia mangostana L.), an extraction method for industrial application was explored. A high yield of α-mangostin (5.2%) was obtained by extraction from dried mangosteen pericarps with subsequent purification on macroporous resin HPD-400. The chemical structure of α-mangostin was verified mass spectrometry (MS), nuclear magnetic resonance (1H NMR and 13C NMR), infrared spectroscopy (IR) and UV-Vis spectroscopy. The purity of the obtained α-mangostin was 95.6% as determined by HPLC analysis. The binding of native α-mangostin to human serum albumin (HSA) or transferrin (TRF) was explored by combining spectral experiments with molecular modeling. The results showed that α-mangostin binds to HSA or TRF as static complexes but the binding affinities were different in different systems. The binding constants and thermodynamic parameters were measured by fluorescence spectroscopy and absorbance spectra. The association constant of HSA or TRF binding to α-mangostin is 6.4832×105 L/mol and 1.4652×105 L/mol at 298 K and 7.8619×105 L/mol and 1.1582×105 L/mol at 310 K, respectively. The binding distance, the energy transfer efficiency between α-mangostin and HSA or TRF were also obtained by virtue of the Förster theory of non-radiation energy transfer. The effect of α-mangostin on the HSA or TRF conformation was analyzed by synchronous spectrometry and fluorescence polarization studies. Molecular docking results reveal that the main interaction between α-mangostin and HSA is hydrophobic interactions, while the main interaction between α-mangostin and TRF is hydrogen bonding and Van der Waals forces. These results are consistent spectral results. [ABSTRACT FROM AUTHOR]

LaAgFeO/halloysites nanotubes (HNTs) nanocomposite was synthesized by sol-gel method. It was characterized by X-ray diffraction, transmission electron microscope, Fourier transform infrared spectroscopy and UV-visible diffused reflectance spectroscopy measurements. The photo-activity of the LaAgFeO/HNTs nanocomposite was evaluated via degradation of methylene blue (MB) under visible-light irradiation. The results showed that the HNTs with unique pore structure favored the adsorption of organic molecules. Adequate Ag doping improved the absorption ability for visible light. The LaAgFeO/HNTs demonstrated the best photocatalytic performance, which achieved as high as 99 % for MB degradation exposed 2 h irradiation. However,further increasing of Ag doping gradually reduced the photocatalytic activity. The nanocomposite catalyst showed outstanding recyclability after eight cycles which still remained up to 90 %. [ABSTRACT FROM AUTHOR]