Assembling Ag@CuO/UiO-66-NH2 nanocomposites for efficient photocatalytic degradation of xylene.

Achieving efficient and stable photocatalytic degradation of xylene hinges on the advancement of photocatalytic materials with outstanding visible light activity. This low-carbon strategy serves as a promising solution to combat air pollution effectively. In this study, we synthesized a Z-scheme heterojunction Ag@CuO/UiO-66-NH2 nanocomposite by hydrothermal method to investigate its photodegradation properties for xylene gas under visible light conditions. XRD, XPS, SEM, FTIR, and UV-vis analyses were employed to confirm the presence of the Z-scheme heterojunction. The CuO/UiO-66-NH2 (CuU-2) composite has high photocatalytic activity, which is 2.37 times that of the original UiO-66-NH2. The incorporation of Z-scheme heterojunction facilitates efficient charge transfer and separation, leading to a substantial enhancement in photocatalytic activity. The Ag@CuO/UiO-66-NH2 (Ag-1@CuU) composite has the highest photocatalytic activity with a degradation efficiency of 84.12%, which is 3.36 times and 1.41 times that of UiO-66-NH2 and CuO/UiO-66-NH2, respectively. The silver cocatalyst improves the absorption capacity of the composite material to visible light, makes the ultraviolet visible absorption edge redshift, and significantly improves the photocatalytic performance. This study introduces a novel approach for xylene gas degradation and offers a versatile strategy for designing and synthesizing metal-organic framework (MOF)-based photocatalysts with exceptional performance.

Hollow Nanoreactors for Controlled Photocatalytic Behaviors: Fundamental Theory, Structure-Performance Relationship, and Catalytic Advantages.

Hollow nanoreactors (HoNRs) have regarded as an attractive catalytic material for photocatalysis due to their exceptional capabilities in enhancing light harvesting, facilitating charge separation and transfer, and optimizing surface reactions. Developing novel HoNRs offers new options to realize controllable catalytic behavior. However, the catalytic mechanism of photocatalysis occurring in HoNRs has not yet been fully revealed. Against this backdrop, this review elaborates on three aspects: 1) the fundamental theoretical insights of HoNRs-driven photocatalytic kinetics; 2) structure-performance relationship of HoNRs to photocatalysis; 3) catalytic advantages of HoNRs in photocatalytic applications. Specifically, the review focuses on the fundamental theories of HoNRs for photocatalysis and their structural advantages for strengthening light scattering, promoting charge separation and transfer, and facilitating surface reaction kinetics, and the relationship between key structural parameters of HoNRs and their photocatalytic performance is in-depth discussed. Also, future prospects and challenges are proposed. It is anticipated that this review paper will pave the way for forthcoming investigations in the realm of HoNRs for photocatalysis.

Influence of high altitude on the strength of aerated concrete.

Aerated concrete specimens were prepared at Fuzhou and Lhasa with the same processing conditions. The compressive strengths of the specimens in Lhasa were lower than that in Fuzhou. We used SEM-EDS, XRD, FT-IR and MIP to study their microstructure in order to find the reasons made for differences in strength. Furthermore, the effect of the preparation process on the material strength was analyzed. The results showed that a low ambient temperature affected the autoclave curing process of the aerated concrete. A longer time was needed to reach the desired constant temperature, resulting in an insufficient degree of hydration, a low level of tobermorite generation, poor crystallinity, high porosity, an uneven pore size distribution, more harmful pore content above 200 nm and unsatisfactory strength. Under low environmental pressure, increasing autoclave pressure can promote the better formation of tobermorite to improve the strength of aerated concrete.

Novel quantification of formation trend and reaction efficiency of hydroxyl radicals for investigating photocatalytic mechanism of Fe-doped TiO2 during UV and visible light-induced degradation of acid orange 7.

A detailed mechanistic investigation of the hydroxyl radical (•OH) formation and organic pollutant degradation over transition metal-doped and undoped TiO2 photocatalysts was performed by the quantitative measurement of •OH and the identification of intermediate products under various experimental conditions. The Fe-doped TiO2 as a typical subject was prepared, characterized and used to degrade an azo dye Acid Orange 7 (AO7). It is indicated that the enhanced photocatalytic activity of Fe-doped TiO2 for AO7 degradation was attributed to the increase in surface area, the facilitated charge transfer via Fe-dopant, and a red shift of absorbable wavelength, maintaining a great formation of •OH under visible irradiation. The oxidation of H2O by holes was estimated as the major pathway of •OH formation rather than the reduction of dissolved O2 by electrons, and their formation trends reached to approximately 75% and 25%, respectively. Meanwhile the synergistic effect of Fe-dopant produced nearly 10% of extra •OH by visible light photoactivation. The intermediate products and pathways of AO7 degradation varied greatly with different photocatalysts and conditions of the process, involving several reaction mechanisms such as the azo bond cleaving, naphthalene oxidation, desulfonation, and hydroxylated products generation. Through the quantification of •OH-reacted efficiency we proposed, a stoichiometry of •OH affecting overall reaction mechanisms in the TiO2-assisted photodegradation of AO7 was further established. This study can provide new insights on how to better clarify the variation regularity of organic pollutant degradation from different treatments of the •OH-based advanced oxidation processes.

A novel cellulose/chitosan composite nanofiltration membrane prepared with piperazine and trimesoyl chloride by interfacial polymerization.

Bamboo cellulose (BC) is one of the most abundant renewable, hydrophilic, inexpensive, and biodegradable organic materials. The cellulose membrane is one of the best materials for replacing petroleum-based polymer films used for water purification. In this study, N-methylmorpholine-N-oxide (NMMO) was used as a solvent to dissolve cellulose and chitosan, and a regenerated cellulose/chitosan membrane (BC/CSM) was prepared by phase inversion. A new kind of cellulose/chitosan nanofiltration membrane (IP-BC/CS-NFM) was obtained by the interfacial polymerization of piperazine (PIP) and trimesoyl chloride (TMC). The IP-BC/CS-NFM was characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), thermal gravimetric analysis (TGA), the retention rate, and water flux. FT-IR analysis showed that polypiperazine amide was formed. Additionally, FE-SEM and AFM showed that a uniform roughness and dense functional layer was formed on the surface of the IP-BC/CS-NFM. Furthermore, TGA analysis showed that the thermal stability of IP-BC/CS-NFM is better than that of BC/CSM. The inorganic salt retention of IP-BC/CS-NFM was measured using a membrane performance evaluation instrument, following the order R(Na2SO4) > R(MgSO4) > R(MgCl2) > R(NaCl). At a pressure of 0.5 MPa, the retention rates for NaCl, Na2SO4, MgSO4, MgCl2, Methyl Orange, and Methyl Blue were 40.26%, 71.34%, 62.55%, 53.28%, 93.65%, and 98.86%, and the water flux values were 15.64, 13.56, 14.03, 14.88, 13.28, and 12.35 L m-2 h-1, respectively. The IP-BC/CS-NFM showed better water flux and a higher rejection rate in aqueous dye-salt solutions, and had a good separation performance under different operating pressure conditions.

A three-dimensional DNA walker amplified FRET sensor for detection of telomerase activity based on the MnO2 nanosheet-upconversion nanoparticle sensing platform.

A novel fluorescent sensing platform for telomerase activity assay was developed by coupling a three-dimensional (3D) DNA walker with the MnO2 nanosheet-upconversion nanoparticle (UCNPs) complex-based fluorescence resonance energy-transfer (FRET) system.

Manganese-phenolic network-coated black phosphorus nanosheets for theranostics combining magnetic resonance/photoacoustic dual-modal imaging and photothermal therapy.

In this work, we directly coated a layer of tannic acid (TA)-Mn2+ chelate networks on black phosphorus (BP) nanosheets (BPNSs) via a simple one-step method. The as-synthesized TA-Mn2+ chelate-coated BPNSs (BPNS@TA-Mn) have excellent T1 MRI contrast enhancement capability, good photoacoustic imaging performance, and high photothermal conversion efficiency, showing great potential in imaging-guided photothermal therapy.

Decomposition pathways of polytetrafluoroethylene by co-grinding with strontium/calcium oxides.

Waste polytetrafluoroethylene (PTFE) could be easily decomposed by co-grinding with inorganic additive such as strontium oxide (SrO), strontium peroxide (SrO2) and calcium oxide (CaO) by using a planetary ball mill, in which the fluorine was transformed into nontoxic inorganic fluoride salts such as strontium fluoride (SrF2) or calcium fluoride (CaF2). Depending on the kind of additive as well as the added molar ratio, however, the reaction mechanism of the decomposition was found to change, with different compositions of carbon compounds formed. CO gas, the mixture of strontium carbonate (SrCO3) and carbon, only SrCO3 were obtained as reaction products respectively with equimolar SrO, excess SrO and excess SrO2 to the monomer unit CF2 of PTFE were used. Excess amount of CaO was needed to effectively decompose PTFE because of its lower reactivity compared with strontium oxide, but it promised practical applications due to its low cost.

Mechanochemical processing of molybdenum and vanadium sulfides for metal recovery from spent catalysts wastes.

This work describes the mechanochemical transformations of molybdenum and vanadium sulfides into corresponding molybdate and vanadate, to serve as a new environment-friendly approach for processing hazardous spent hydrodesulphurization (HDS) catalysts solid waste to achieve an easy recovery of not only molybdenum and vanadium but also nickel and cobalt. Co-grinding the molybdenum and vanadium sulfides with oxidants and sodium carbonate stimulates solid-state reactions without any heating aid to form metal molybdates and vanadates. The reactions proceed with an increase in grinding time and were enhanced by using more sodium carbonate and stronger oxidant. The necessary conditions for the successful transformation can be explained on the basis of thermodynamic analyses, namely a negative change in Gibbs free energy.

Effect of γ-PGA on the formation of collagen fibrils in vitro.

The effect of γ-poly(glutamic acid) (γ-PGA) on the self-assembly of collagen was studied. Under physiological conditions, the kinetic curves for fibril formation showed that the turbidity of collagen/γ-PGA blends at 313 nm was increased with the addition of γ-PGA. Furthermore, it was shown using both field-emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) that fibrils with a larger diameter were obtained following the addition of γ-PGA, probably due to the electrostatic and hydrogen bond interactions between collagen and γ-PGA, which promoted the lateral association of collagen molecules. In addition, both the thermal stability and viscoelastic properties of the hybrid hydrogels, which were evaluated by differential scanning calorimetry and rheological measurements, respectively, were improved by the addition of γ-PGA.

Identification of a new cyathane diterpene that induces mitochondrial and autophagy-dependent apoptosis and shows a potent in vivo anti-colorectal cancer activity.

Diterpenes has been reported to possess multiple bioactivities consisting of anti-microbial and anti-inflammatory properties. This study reveals a new cyathane-type diterpene (cyathin Q) from the culture of the fungus Cyathus africanus by bioactivity-guided separation. The structure of cyathin Q was determined based on spectroscopic measurements (NMR and MS). The bioactivity evaluation shows that cyathin Q has a strong anticancer activity against HCT116 cells and Bax-deficient HCT116 in vitro and in vivo. This compound induced hallmarks of apoptotic events in HCT116 cells, including caspase activation, cytochrome c release, poly (ADP-ribose) polymerase (PARP) cleavage, and depolarization of the mitochondrial inner transmembrane potential. This process is accompanied with the increased mitochondrial ROS, down-regulation of Bcl-2 protein, and up-regulation of Bim protein. We also observed the cleavage of autophagy-related protein ATG5 in cyathin Q-induced apoptosis. Taken together, our study identified a new fungal diterpene that exhibited anticancer activity via induction of mitochondria and autophagy-dependent apoptosis in HCT116 cells.

Microsporols A-C from the Plant Endophytic Fungus Pestalotiopsis microspore.

Three new ambuic acid derivatives, microsporols A-C (1-3) and the known compound ambuic acid (4), were isolated from the solid-substrate fermentation cultures of the plant endophytic fungus Pestalotiopsis microspora. Their structures were elucidated primarily by NMR experiments. The absolute configurations of the 6,7-diol moiety in 1 and 2 were assigned using the Snatzke's method, whereas that of 3 was deduced by circular dichroism (CD) exciton chirality method. Compounds 1, 3, and 4 showed moderate 5-lipoxygenase (5-LOX) inhibitory effects.

Trichodermone, a spiro-cytochalasan with a tetracyclic nucleus (7/5/6/5) skeleton from the plant endophytic fungus Trichoderma gamsii.

Trichodermone (1), the first spiro-cytochalasan with an unprecedented tetracyclic nucleus (7/5/6/5), together with its possible biosynthetic precursor aspochalasin D (2), was isolated from the endophytic fungus Trichoderma gamsii. Compound 2 displayed moderate inhibitory activity against HeLa cells with an IC50 value of 5.72 µM.