Corrosion inhibition activity of a natural polysaccharide from Dysosma versipellis using tailor-made deep eutectic solvents.

In this work, a total of 18 types of choline chloride, betaine, and L-proline-based deep eutectic solvents (DESs) were synthesized to determine the extraction yield of a natural polysaccharide (PSA) from Dysosma versipellis using an ultrasound-assisted extraction method. Results indicate that the choline-oxalic acid-based DES has the best extraction yield for PSA due to the proper physical-chemical properties between PSA and DES. To evaluate the optimal extraction conditions, a response surface methodology was carried out. Under the optimal conditions, the extraction yield of PSA reaches 10.37 % (± 0.03 %), higher than the conventional extraction methods. Findings from FT-IR and NMR suggest that the extracted PSA belongs to a neutral polysaccharide with (1 â†’ 6)-linked α-d-glucopyranose in the main chain. Interestingly, results from various electrochemical measurements show the extracted PSA exhibits excellent corrosion inhibition performance for mild steel (MS) in a 0.5 M HCl solution, with 90.8 % of maximum corrosion inhibition efficiency at 210 mg L-1. SEM and XPS measurements reveal the formation of a protective layer on the MS surface. The adsorption behaviour of extracted PSA well obeys the Langmuir adsorption isotherm containing the chemisorption and physisorption. Additionally, theoretical calculations validate the experimental findings.

Highly selective photocatalytic CO2 reduction and hydrogen evolution facilitated by oxidation induced nitrogen vacancies on g-C3N4.

The introduction of nitrogen vacancies into polymeric carbon nitride (PCN) has been attested to be a reliable strategy to enhance photocatalytic performance. Nitrogen vacancies were considered as active sites to promote the adsorption of target molecules and capture photoexcited electrons to inhibit the recombination of charge pairs, accelerate photoinduced electrons to participate in photocatalytic reaction. In this paper, a series of PCN with rich nitrogen vacancies were prepared by etching of chromic acid solution. Sample 20KCSCN had the highest photocatalytic performance whose evolution efficiency of CO2 to CO and CH4 can reach 3.9 and 0.5 µmol·g-1·h-1, respectively. These evolution efficiencies are 2.9 and 4 times higher than that of the PCN. Meanwhile, 20KCSCN demonstrates high CO conversion selectivity and stability. The successful introduction of nitrogen vacancies not only increases the active sites of PCN surface, but also optimizes the optical structure, which dramatically boosts the separation of photoexcited charge pairs and the reduction capacity of photogenerated electrons. The enhancement mechanism for photocatalytic CO2 reduction performance of PCN was proposed. Besides, photocatalytic H2 evolution experiments were performed on all samples to confirm the universality of PCN photocatalytic activity enhancement etched by chromic acid solution. H2 evolution rate on 20KCSCN can reach 652 µmol·g-1·h-1, which is 1.6-fold higher than that on PCN (254 µmol·g-1·h-1) after 4 h irradiation under a 300 W Xe lamp. This work offers new venue for introducing nitrogen vacancies in PCN to regulate photoexcited charge pairs transfer. The photocatalytic enhancement of CO2 reduction could be used to alleviate the serious issue of excessive CO2 emission and energy crisis.

Advances in the Utilization of Zebrafish for Assessing and Understanding the Mechanisms of Nano-/Microparticles Toxicity in Water.

A large amount of nano-/microparticles (MNPs) are released into water, not only causing severe water pollution, but also negatively affecting organisms. Therefore, it is crucial to evaluate MNP toxicity and mechanisms in water. There is a significant degree of similarity between the genes, the central nervous system, the liver, the kidney, and the intestines of zebrafish and the human body. It has been shown that zebrafish are exceptionally suitable for evaluating the toxicity and action mechanisms of MNPs in water on reproduction, the central nervous system, and metabolism. Providing ideas and methods for studying MNP toxicity, this article discusses the toxicity and mechanisms of MNPs from zebrafish.

Substantially boosted photocatalytic detoxification activity of TiO2 benefited from Eu doping.

The wide energy band and high recombination rate of photogenerated carriers severely limit the photocatalytic activity of TiO2. It has been demonstrated that ion doping can induce lattice defects, change the energy band structure, optimize the separation efficiency of photogenerated carrier, thus promoting the photocatalytic activity of the catalyst. In this work, Eu-doped TiO2 was synthesized by a sol-gel method, and the composition and photogenerated carrier separation efficiency of the samples were analysed by various characterization methods. The results show that Eu-TiO2 was successfully prepared and Eu-TiO2 exhibits higher photogenerated carrier separation efficiency and generates more superoxide radicals compared to the bare TiO2. Photocatalytic activity of the samples was evaluated by the degradation of Rhodamine B (RhB), and the results show that Eu doping improves the photocatalytic activity of the samples, the sample with Eu/Ti molar ratio of 0.2% displays 2.3-fold increase in photocatalytic activity compared to the blank TiO2. The improved photocatalytic activity can be attributed to the fact that Eu doping facilitates the effective separation of photogenerated carriers.

Ionic liquids assisted preparation of BiPO4 photocatalyst with enhanced photocatalytic activity for tetracycline and rhodamine B removal.

In this work, BiPO4 (BPO)-based photocatalyst was successfully synthesized by a conventional hydrothermal strategy using bismuth nitrate pentahydrate (Bi(NO3)3·5H2O) and 1-ethyl-3-methylimidazolium dihydro phosphate ([EMIm]H2PO4). [EMIm]H2PO4 can serve as a phosphorus source and surfactant. Photocatalytic activities of the photocatalysts prepared were evaluated by the destruction of rhodamine B (RhB) and tetracycline (TC) under UV light irradiation, respectively. The results reveal that the sample (IL-BPO) synthesized with the assistance of ionic liquid exhibits enhanced photocatalytic activity in comparison with the reference BiPO4. The significantly improved photocatalytic activity of IL-BPO can be mainly attributed to the boosted separation of photoinduced electron-hole pairs (e-/h+) and richer oxygen vacancies (OVs).

Boosted photocatalytic performance of OVs-rich BiVO4 hollow microsphere self-assembled with the assistance of SDBS.

In this study, monoclinic phase bismuth vanadate (BiOV4) photocatalyst with unique hollow microsphere morphology was successfully prepared by a hydrothermal method in the existence of sodium dodecyl benzene sulfonate (SDBS). The prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron (SEM) and X-ray photoelectron spectrometer (XPS) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). Experimental results show that SDBS definitely changes the microstructure of BiVO4, which is allocated to the template role of SDBS in the preparation process. Moreover, the hydrothermal treatment time is also of crucial importance in affecting the structure and morphology of the photocatalysts, and the optimal hydrothermal treatment time for the formation of hollow microsphere is 24 h. Furthermore, the feasible growth mechanism for hollow microsphere was elaborated. Enriched oxygen vacancies (OVs) are introduced into BiOV4 prepared with SDBS, largely elevating the separation efficiency of photo-generated charges. Under visible light irradiation, the photocatalytic activities of BiOV4 for destruction of rhodamine (RhB) were evaluated. The photocatalytic degradation rate constant of RhB on the 3SBVO is 2.23 times of that on the blank BiOV4 as the mass ratio of SDBS/BiOV4 is 3 %. Photocatalytic degradation mechanism of BiVO4 toward detoxification of organic pollutants was presented.

MoS2 nanosheets on plasma-nitrogen-doped carbon cloth for high-performance flexible supercapacitors.

With the surging demand for flexible and portable electronic devices featuring high energy and power density, the development of next-generation lightweight, flexible energy storage devices is crucial. However, achieving the expected energy and power density of supercapacitors remains a great challenge. This work reports a facile plasma-enabled method for preparing supercapacitor electrodes made of MoS2 nanosheets grown on flexible and lightweight N-doped carbon cloth (NCC). The MoS2/NCC presents an outstanding specific capacitance of 3834.28 mF/cm2 at 1 mA/cm2 and energy density of 260.94 µWh/cm2 at a power density of 354.48 µW/cm2. An aqueous symmetric supercapacitor fitted with two MoS2/NCC electrodes achieved the maximum energy density of 138.12 µWh/cm2 and the highest power density of 7,417.33 µW/cm2, along with the excellent cycling stability of 83.3 % retention over 10,000 cycles. The high-performance energy storage ASSSs (all-solid-state supercapacitors) are demonstrated to power devices in both rigid and flexible operation modes. This work provides a new perspective for fabricating high-performance all-solid-state flexible supercapacitors for clean energy storage.

Panax notoginseng powder -assisted preparation of carbon-quantum-dots/BiOCl with enriched oxygen vacancies and boosted photocatalytic performance.

Low activity of photocatalysts is a serious bottleneck to the practical application of photocatalytic technology. In this paper, a series of BiOCl composite photocatalysts containing carbon quantum dots (CQDs) were successfully prepared by adding Panax notoginseng powder (PNP) to the solvothermal synthesis system of BiOCl as a template agent and a raw material for 0D CQDs. CQDs/BiOCl exhibit 2D flake structures and 3D flower-like microspheres self-assembled from thin flakes, holding rich oxygen vacancies (OVs). After detailed characterization, it was found that the amount of OVs on BiOCl could be regulated according to the amount of PNP added. The CQDs/OVs-BiOCl photocatalysts exhibit higher photogenerated charge separation efficiency and photocatalytic activity than the bare BiOCl. When the mass ratio of PNP/BiOCl is 1.0%, the photocatalyst demonstrates the maximum degradation activity for rhodamine B (RhB) and perfluorooctanoic acid (PFOA). In view of the solid observations, a photocatalytic enhancement mechanism of CQDs/BiOCl was elucidated.

Secoisolariciresinol diglucoside induces pyroptosis by activating caspase-1 to cleave GSDMD in colorectal cancer cells.

Secoisolariciresinol diglucoside (SDG) is the main component of lignans with various biological activities, including anticancer activity. However, whether SDG has obvious anticancer effects on colorectal cancer (CRC) is unclear. Pyroptosis, a form of programmed cell death, has received increasing attention in cancer-related research. In this study, we aimed to test the anticancer properties and relatecd functional mechanisms of SDG. we found that SDG not only inhibited the cell viability of HCT116 cells, but also induced HCT116 cells to swell with apparent large bubbles, which are typical signs of pyroptosis. Furthermore, SDG induced cell pyroptosis by enhancing cleavage of the N-terminal fragment of gasdermin D (GSDMD) in CRC cells, accompanied by increased caspase-1 cleavage. Consistent with this, SDG-induced GSDMD-N-terminal fragment cleavage and pyroptosis were reduced by siRNA-mediated silencing of caspase-1 or treatment with the specific caspase-1 inhibitor VX-765 treatment, suggesting that active caspase-1 further induces pyroptosis. A mechanistic study showed that SDG induced reactive oxygen species (ROS) accumulation and inhibits phosphatidylinositol 3-kinase (PI3K) phosphorylation and increases pyroptosis, while increasing GSDMD and caspase-1 cleavage and enhancing expression of BCL2-associated X (BAX), which could be rescued by the ROS scavenger (NAC), suggesting that SDG-induced GSDME-dependent pyroptosis is related to the ROS/PI3K/AKT/BAX-mitochondrial apoptotic pathway. In vivo results showed that SDG significantly inhibited tumor growth and induced pyroptosis in the HCT116-CRC nude mouse model. In conclusion, our findings suggest that the anticancer activity of SDG in CRC is associated with the induction of GSDMD-dependent pyroptosis by SDG through the generation of ROS/P13K/AKT/BAK-mitochondrail apoptosis pathway, providing insights into SDG in its potential new application in cancer treatment.

Metal-Organic Frameworks With Variable Valence Metal-Photoactive Components: Emerging Platform for Volatile Organic Compounds Photocatalytic Degradation.

With their outstanding diversities in both structures and performances, newly emerging metal-organic frameworks (MOFs) materials are considered to be the most promising artificial catalysts to meet multiple challenges in the fields of energy and environment. Especially in absorption and conversion of solar energy, a variety of MOFs can be readily designed to cover and harvest the sun irradiation of ultraviolet (UV), visible and near-infrared region through tuning both organic linkers and metal nodes to create optimal photocatalytic efficiency. Nowadays, a variety of MOFs were successfully synthesized as powerful photocatalysts for important redox reactions such as water-splitting, CO2 reduction and aqueous environmental pollutants detoxification. MOFs applications in indoor-air VOCs pollutants cleaning, however, are less concerned partially because of limited diffusion of both gaseous pollutant molecules and photo-induced active species in very porous MOFs structures. In this mini-review, we focus on the major breakthroughs of MOFs as photocatalysts for the effective removal of indoor-air VOCs such as aldehydes, aromatics and short-chain alcohols. According to their nature of photoactive centers, herein MOFs photocatalysts are divided into two categories to comment, that is, MOFs with variable valence metal nodes as direct photoactive centers and MOFs with non-variable valence metal nodes but after combining other photoactive variable valence metal centers as excellent concentrated and concerted electron-transfer materials. The mechanisms and current challenges of the photocatalytic degradation of indoor-air VOC pollutants by these MOFs will be discussed as deeply as possible.

Excellent visible light responsive photocatalytic behavior of N-doped TiO2 toward decontamination of organic pollutants.

In this work, N-doped TiO2 (N-TiO2) with ample and tunable OVs was successfully synthesized, deriving from facile hydrothermal method and baked in the NH3 atmosphere. N-doping boosts the amount of surface hydroxyl and superoxide (O2-) of TiO2, demonstrated by XPS and nitroblue tetrazolium (NBT)-O2- quantitative reaction. Rich and tunable OVs were confirmed by low temperature electron spin resonance (ESR) results, demonstrating that doping of N into TiO2 can definitely construct higher OVs than the reference TiO2. Surface photovoltage spectrum (SPS) test, fluorescence experiments and electrochemical measurements all display that N-TiO2 photocatalysts with OVs have a higher severance efficiency of photogenerated e-/h+ pairs than the pristine TiO2. Photocatalytic evaluation results exhibit that N-TiO2 photocatalysts demonstrate better performance than the reference TiO2 toward decontamination of rhodamine B and tetracycline. TiO2 treated in ammonia atmosphere for 1 h shows the highest photocatalytic property. The visible light responsive catalytic behavior of TiO2 treated in ammonia atmosphere for 1 h is much higher than that of commercial TiO2 (P25) and the pristine TiO2, separately. The ameliorated visible light behavior of N-TiO2 photocatalysts is attributable to rich oxygen vacancies produced through introducing N into TiO2 and the boosted severance of photoactivated e-/h+.

LiGaGe2S6: A Chalcogenide with Good Infrared Nonlinear Optical Performance and Low Melting Point.

In this work, we design and synthesize a new chalcogenide LiGaGe2S6 on the basis of known infrared (IR) material LiGaS2 by partially substituting Ga with Ge. This compound possesses very strong nonlinear (NLO) response (2.5 × LiGaS2) and large band gap (3.52 eV), manifesting a better balance between band gap and NLO response compared with that for LiGaS2. Moreover, LiGaGe2S6 exhibits a much lower melting point (663 °C) than that of LiGaS2 (1050 °C). This would result in the much smaller vapor pressure of sulfur in the fused quartz vessels used for the crystal growth, and thus, it should be greatly beneficial to obtain the large stoichiometric LiGaGe2S6 single crystal. Our studies demonstrate that LiGaGe2S6 is a good candidate material for IR NLO applications.

Enhanced Visible Light Photocatalytic Activity of Br-Doped Bismuth Oxide Formate Nanosheets.

A facile method was developed to enhance the visible light photocatalytic activity of bismuth oxide formate (BiOCOOH) nanosheets via Br-doping. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, the Brunauer-Emmett-Teller surface area, UV-vis diffuse reflectance spectroscopy, photoluminescence spectra, and N2 adsorption-desorption isotherms measurement. The Br- ions replaced the COOH- ions in the layers of BiOCOOH, result in a decreased layer distance. The photocatalytic activity of the as-prepared materials was evaluated by removal of NO in qir at ppb level. The results showed that the Br-doped BiOCOOH nanosheets showed enhanced visible light photocatalytic activtiy with a NO removal of 37.8%. The enhanced activity can be ascribed to the increased visible light absorption and the promoted charge separation.

[Influence of ALA-PDT on fibroblast cells from hypertrophic scars].

OBJECTIVE: To determine the effect of ALA-PDT on fibroblast cells from hypertrophic scars in vitro, and to identify proper dosage of photosensitizer and energy level of laser light. METHODS: Fibroblast cells from hypertrophic scars were cultured in vitro. ALA (5-aminolevulnilic acid) was added into the culture fluid with different concentrations. Then the cultured cells were exposed to He-Ne laser light (PDT) with different energy levels. The cell inhibition rate was measured with CCK-8 method. The expression of PCNA in fibroblast cells was detected after cultured with ALA-PDT, which was selected according to the proper dosage of ALA and laser light from the result of CCK-8. RESULTS: No obvious inhibition effect was detected with laser light or photosensitizer alone on fibroblast cells from hypertrophic scars. The inhibition effect appeared when ALA and PDT applied simultaneously, and the inhibition rate increased with the dosage of photosensitizer and the energy level of laser light. Maximal inhibition effect reached with 20 J/cm2 laser light exposure and 0.5 mmol/L of ALA, the expression of PCNA of ALA-PDT group is lower than control group in this condition (30.33 +/- 2.08 vs. 78.33 +/- 3.79, P < 0.05). CONCLUSION: The inhibition effect of ALA-PDT on fibroblast cells from hypertrophic scars increases with the dosage of photosensitizer and the energy level of He-Ne laser light. The proper dosage of ALA is 0.5 mmol/L along with 20 J/cm2 laser light exposure.

[Study on the inhibitory effect of ALA-PDT on the proliferation of fibroblasts from keloid].

OBJECTIVE: To investigate the effects of ALA-PDT on the proliferation of fibroblasts from keloid in vitro, and to find the most efficient concentration of photosensitizer and the energy of He-Ne laser light. METHODS: The fibroblast cells from keloid cultured in vitro were divided into blank control group, laser light group (only with different dose energy of He-Ne laser light), photosensitizer group(only with different concentration of ALA) and ALA-PDT group (treated by photosensitizer and laser light). After the above treatments were finished, the inhibition rate of each group was measured with MTT method. RESULTS: There is no obvious inhibitory effect on the fibroblast cells from keloid in laser light group and photosensitizer group, In ALA-PDT groups, when the concentration of ALA and the dose of energy of He-Ne laser light reached some extent (>0.125 mmol/L and >10 J/cm2 respectively), the inhibitory effect of ALA-PDT kept rising with the increase of the concentration of ALA and the energy of He-Ne laser light. The most appropriate concentration for ALA is 0.25 mmol/L, while the energy for He-Ne laser light is 40 J/cm2. CONCLUSION: The inhibitory effect, of ALA-PDT on the proliferation of fibroblasts from keloid could be enhanced with the increase of photosensitizer concentration and laser light energy.

Remove cooking fume using catalytic combustion over Pt/La-Al2O3.

Five monolithic catalysts with low noble metal content were prepared by immerge method (Pt/gamma-Al2O3, Pt/La-Al2O3, Pt/YSZ-Al2O3, Pt+Pd/La-Al2O3 and Pd/La-Al2O3) and their activity measurements were carried out in a conventional fixed-bed flow reactor. The results show that La-Al2O3 can promote activity of the prepared catalysts and can decrease the complete conversion temperature of cooking fume. The Pt/La-Al2O3 catalyst has the highest activity and can be applied in wide range of gas hourly space velocity (GHSV). Some characterizations (XRD, TPR) were carried out with the objective to explain differences in catalytic behaviors. The prepared catalyst showed a great potential for application.

Photocatalytic degradation of gaseous benzene over TiO2/Sr2CeO4: preparation and photocatalytic behavior of TiO2/Sr2CeO4.

The paper demonstrates that the photocatalytic activity of TiO(2) towards the decomposition of gaseous benzene in a batch reactor can be greatly improved by loading TiO(2) on the surface of Sr(2)CeO(4). The research investigates the optimum loading amount of TiO(2) on Sr(2)CeO(4) in enhancing the photocatalytic activity of TiO(2). The prepared photocatalyst was characterized by XRD, UV-vis diffuse reflectance and XPS analyses. TiO(2) is loaded on Sr(2)CeO(4) at 773K. TiO(2)/Sr(2)CeO(4) absorbs much more visible light than TiO(2). The XPS spectrum shows that there are Ti, O, C, Sr elements on the surface of the TiO(2)/Sr(2)CeO(4), and that the binding energy value of Ti2p transfers to a lower value. TiO(2)/Sr(2)CeO(4) demonstrates 2.0 times the photocatalytic activity of pure TiO(2). Based upon these observations, the mechanistic role of Sr(2)CeO(4) in the photocatalytic oxidation reaction has been suggested.

Photocatalytic degradation of gaseous benzene over TiO2/Sr2CeO4: kinetic model and degradation mechanisms.

Photocatalytic oxidation of benzene in air was carried out over TiO2/Sr2CeO4 catalysts. The prepared photocatalyst was characterized by SBET, UV-vis diffuse reflectance and XPS. TiO2/Sr2CeO4 absorbs much more visible light than TiO2 in the visible light region. The XPS spectrum shows that the binding energy value of Ti 2p3/2 transfers to a lower value. The main purpose was to investigate the kinetic model and degradation mechanisms. The kinetic data matched well with the Langmuir-Hinshelwood (L-H) kinetic model with the limiting rate constant and the adsorption constant in this case were 0.0064 mg l-1 min-1 and 9.2078 l mg-1, respectively. No gas-phase intermediates were detected by direct GC/FID analysis under the conditions despite the high benzene concentration. Ethyl acetate and (3-methyl-oxiran-2-yl)-methanol were two major identified intermediates which were accompanied by butylated hydroxytoluene, 2,6-bis(1,1-dimethylethyl)-4,4-dimethylycyclohe, 2,5-cyclohexadiene-1,4,dione,2,6-bis(1,1-dim). It is plausible that at least one of these less-reactive intermediates caused the deactivation of the photocatalyst. Finally, the photocatalytic oxidation mechanisms were speculated.