Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Más filtros










Intervalo de año de publicación
1.
J Hazard Mater ; 469: 133893, 2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38452684

RESUMEN

Sensitive and rapid identification of volatile organic compounds (VOCs) at ppm level with complex composition is vital in various fields ranging from respiratory diagnosis to environmental safety. Herein, we demonstrate a SERS gas sensor with size-selective and multiplexed identification capabilities for VOCs by executing the pre-enrichment strategy. In particular, the macro-mesoporous structure of graphene aerogel and micropores of metal-organic frameworks (MOFs) significantly improved the enrichment capacity (1.68 mmol/g for toluene) of various VOCs near the plasmonic hotspots. On the other hand, molecular MOFs-based filters with different pore sizes could be realized by adjusting the ligands to exclude undesired interfering molecules in various detection environments. Combining these merits, graphene/AuNPs@ZIF-8 aerogel gas sensor exhibited outstanding label-free sensitivity (up to 0.1 ppm toluene) and high stability (RSD=14.8%, after 45 days storage at room temperature for 10 cycles) and allowed simultaneous identification of multiple VOCs in a single SERS measurement with high accuracy (error < 7.2%). We visualize that this work will tackle the dilemma between sensitivity and detection efficiency of gas sensors and will inspire the design of next-generation SERS technology for selective and multiplexed detection of VOCs.

2.
J Colloid Interface Sci ; 663: 31-42, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38387184

RESUMEN

The construction of van der Waals (vdW) heterojunctions is a key approach for efficient and stable photocatalysts, attracting marvellous attention due to their capacity to enhance interfacial charge separation/transfer and offer reactive sites. However, when a vdW heterojunction is made through an ex-situ assembly, electron transmission faces notable obstacles at the components interface due to the substantial spacing and potential barrier. Herein, we present a novel strategy to address this challenge via wet chemistry by synthesizing a functionalized graphene-modulated Z-scheme vdW heterojunction of zinc phthalocyanine/tungsten trioxide (xZnPc/yG-WO3). The functionalized G-modulation forms an electron "bridge" across the ZnPc/WO3 interface to improve electron transfer, get rid of barriers, and ultimately facilitating the optimal transfer of excited photoelectrons from WO3 to ZnPc. The Zn2+ in ZnPc picks up these excited photoelectrons, turning CO2 into CO/CH4 (42/22 µmol.g-1.h-1) to deliver 17-times better efficiency than pure WO3. Therefore, the introduction of a molecular "bridge" as a means to establish an electron transfer conduit represents an innovative approach to fabricate efficient photocatalysts designed for the conversion of CO2 into valued yields.

3.
J Colloid Interface Sci ; 661: 544-563, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38308894

RESUMEN

The realization of 2D/2D Van der Waals (VDW) heterojunctions represents an advanced approach to achieving superior photocatalytic efficiency. However, electron transfer through Van der Waals heterojunctions formed via ex-situ assembly encounters significant challenges at the interface due to contrasting morphologies and potential barriers among the nanocomposite substituents. Herein, a novel approach is presented, involving the insertion of a phosphate group between copper phthalocyanine (CuPc) and B-doped and N-deficient g-C3N4 (BDCNN), to design and construct a Van der Waals heterojunction labeled as xCu[acs]/yP-BDCNN. The introduction of phosphate as a charge modulator and efficient conduit for charge transfer within the heterojunction resulted in the elimination of spatial barriers and induced electron movement from BDCNN to CuPc in the excited states. Consequently, the catalytic central Cu2+ in CuPc captured the photoelectrons, leading to the conversion of CO2 to C2H4, CO and CH4. Remarkably, this approach resulted in a 78-fold enhancement in photocatalytic efficiency compared to pure BDCNN. Moreover the findings confirm that the 2D-2D 4Cu[acs]/9P-BDCNN sheet-like heterojunction effectively boosts photocatalytic activity for persistent pollutants such as methyl orange (MO), methylene blue (MB), rhodamine B (RhB), and tetracycline antibiotics (TCs). The introduction of "interfacial interacting" substances to establish an electron transfer pathway presents a novel and effective strategy for designing photocatalysts capable of efficiently reducing CO2 into valuable products.

4.
Nanoscale ; 16(9): 4352-4377, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38275275

RESUMEN

Semiconductor-based photocatalysis has attracted significant interest due to its capacity to directly exploit solar energy and generate solar fuels, including water splitting, CO2 reduction, pollutant degradation, and bacterial inactivation. However, achieving the maximum efficiency in photocatalytic processes remains a challenge owing to the speedy recombination of electron-hole pairs and the limited use of light. Therefore, significant endeavours have been devoted to addressing these issues. Specifically, well-designed heterojunction photocatalysts have been demonstrated to exhibit enhanced photocatalytic activity through the physical distancing of electron-hole pairs generated during the photocatalytic process. In this review, we provide a systematic discussion ranging from fundamental mechanisms to material strategies, focusing on TiO2-based heterojunction photocatalysts. Current efforts are focused on developing heterojunction photocatalysts based on TiO2 for a variety of photocatalytic applications, and these projects are explained and assessed. Finally, we offer a concise summary of the main insights and challenges in the utilization of TiO2-based heterojunction photocatalysts for photocatalysis. We expect that this review will serve as a valuable resource to improve the efficiency of TiO2-based heterojunctions for energy generation and environmental remediation.

5.
J Biomol Struct Dyn ; : 1-15, 2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37551015

RESUMEN

During last decades, 3,5-disubstituted-tetrahydro-2H-thiadiazine-2-thione scaffold remains the center of interest due to their ease of preparation, diverse range substituents at N-3 and N-5 positions, and profound biological activities. In the current study, a series of 3,5-disubstituted-tetrahydro-2H-thiadiazine-2-thiones were synthesized in good to excellent yield, and the structure of the compounds were confirmed by various spectroscopic techniques such as FTIR, 1H-NMR, 13C-NMR and Mass spectrometry, and finally evaluated against Leishmania major. Whereas, all the evaluated compounds (1-33), demonstrate potential leishmanicidal activities with IC50 values in the range of (1.30- 149.98 uM). Among the evaluated compounds such as 3, 4, 6, and 10 exhibited excellent leishmanicidal activities with IC50 values of (2.17 µM), (2.39 µM), (2.00 µM), and (1.39 µM), respectively even better than the standard amphotericin B (IC50 = 0.50) and pentamidine (IC50 = 7.52). In order to investigate binding interaction of the most active compounds, molecular docking study was conducted with Leishmania major. Further molecular dynamic simulation study was also carried out to assess the stability and correct binding of the most active compound 10, within active site of the Leishamania major. Likewise, the physiochemical properties, drug likeness, and ADMET of the most active compounds were investigated, it was found that none of the compounds violate Lipiniski's rule of five, which show that this class of compounds had enough potential to be used as drug candidate in near future.Communicated by Ramaswamy H. Sarma.

6.
Curr Opin Chem Biol ; 76: 102367, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37453164

RESUMEN

Historically, bacterial natural products have served as an excellent source of drug leads, however, in recent decades the rate of discovery has slowed due to multiple challenges. Rapid advances in genome sequencing science in recent years have revealed the vast untapped encoded potential of bacteria to make natural products. To access these molecules, researchers can employ the ever-growing array of bioinformatic tools at their disposal and leverage newly developed experimental approaches to validate these bioinformatic-driven hypotheses. When used together effectively, bioinformatic and experimental tools enable researchers to deeply examine the full diversity of bacterial natural products. This review briefly outlines recent bioinformatic tools that can facilitate natural product research in bacteria including the use of CRISPR, co-occurrence network analysis, and combinatorial generation of microbial natural products to test bioinformatic hypotheses in the lab.


Asunto(s)
Productos Biológicos , Productos Biológicos/farmacología , Biología Computacional/métodos , Bacterias/genética
7.
ACS Omega ; 8(23): 20412-20422, 2023 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-37332823

RESUMEN

Dihydropyrazole (1-22) derivatives were synthesized from already synthesized chalcones. The structures of all of the synthesized compounds were confirmed by elemental analysis and various spectroscopic techniques. Furthermore, the synthesized compounds were screened against α amylase as well as investigated for antioxidant activities. The synthesized compounds demonstrate good to excellent antioxidant activities with IC50 values ranging between 30.03 and 913.58 µM. Among the 22 evaluated compounds, 11 compounds exhibit excellent activity relative to the standard ascorbic acid IC50 = 287.30 µM. Interestingly, all of the evaluated compounds show good to excellent α amylase activity with IC50 values lying in the range between 0.5509 and 810.73 µM as compared to the standard acarbose IC50 = 73.12 µM. Among the investigated compounds, five compounds demonstrate better activity compared to the standard. In order to investigate the binding interactions of the evaluated compounds with amylase protein, molecular docking studies were conducted, which show an excellent docking score as compared to the standard. Furthermore, the physiochemical properties, drug likeness, and ADMET were investigated, and it was found that none of the compounds violate Lipiniski's rule of five, which shows that this class of compounds has enough potential to be used as a drug candidate in the near future.

8.
J Hazard Mater ; 457: 131846, 2023 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-37320905

RESUMEN

Fabrication of highly elastic three-dimensional aerogel adsorbents with outstanding adsorption capacities is a long pursuit for the treatment of industrial contaminated water. In this work, a magnetic reduced graphene oxide (rGO)/Fe3O4/carbon nanotubes (CNTs) aerogel material was constructed by the electrostatic attraction between the negatively charged GO and positively charged CNTs following a one-pot water bath treatment. The as-synthesized aerogel demonstrated high compressive stress (28.4 kPa) and lower density (24.11 mg/cm3) with exceptional adsorption capacities for versatile adsorbates which are attributed to CNTs and magnetic Fe3O4 nanoparticles. The effect of pH, initial concentration of adsorbates (dyes, Cd (ІІ) ions, organic solvents, and pump oil), content of CNTs and cyclic times on the adsorption capacities of the aerogel were investigated in detail. Furthermore, from simulation, the adsorption kinetics, and thermodynamics of the aerogel for adsorbates were more satisfied by endothermic quasi-second-order kinetic model with characteristic physical adsorption. Thus, the optimized rGO/Fe3O4/CNTs-10 aerogel adsorbent can be used as a powerful and versatile tool to deal with contaminated industrial or domestic wastewater.

9.
Ultrason Sonochem ; 95: 106409, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37099855

RESUMEN

Sonocatalysis has attracted excellent research attention to eradicate hazardous pollutants from the environment effectively. This work synthesised an organic/inorganic hybrid composite catalyst by coupling Fe3O4@MIL-100(Fe) (FM) with ZnS nanoparticles using the solvothermal evaporation method. Remarkably, the composite material delivered significantly enhanced sonocatalytic efficiency for removing tetracycline (TC) antibiotics in the presence of H2O2 compared to bare ZnS nanoparticles. By adjusting different parameters such as TC concentration, catalyst dosage and H2O2 amount, the optimized composite (20 %Fe3O4@MIL-100(Fe)/ZnS) removed 78.25% antibiotic in 20 min at the cost of 1 mL of H2O2. These much superior activities are attributed to the efficient interface contact, effective charge transfer, accelerated transport capabilities and strong redox potential for the superior acoustic catalytic performance of FM/ZnS composite systems. Based on various characterization, free radical capture experiments and energy band structures, we proposed a mechanism for the sonocatalytic degradation of tetracycline based on S-scheme heterojunctions and Fenton like reactions. This work will provide an important reference for developing ZnS-based nanomaterials to study sonodegradation of pollutants.


Asunto(s)
Contaminantes Ambientales , Nanopartículas , Peróxido de Hidrógeno/química , Agua/química , Antibacterianos/química , Tetraciclina/química , Catálisis
10.
ACS Sens ; 8(3): 1287-1298, 2023 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-36867056

RESUMEN

High sensitivity, good signal repeatability, and facile fabrication of flexible surface enhanced Raman scattering (SERS) substrates are common pursuits of researchers for the detection of probe molecules in a complex environment. However, fragile adhesion between the noble-metal nanoparticles and substrate material, low selectivity, and complex fabrication process on a large scale limit SERS technology for wide-ranging applications. Herein, we propose a scalable and cost-effective strategy to a fabricate sensitive and mechanically stable flexible Ti3C2Tx MXene@graphene oxide/Au nanoclusters (MG/AuNCs) fiber SERS substrate from wet spinning and subsequent in situ reduction processes. The use of MG fiber provides good flexibility (114 MPa) and charge transfer enhancement (chemical mechanism, CM) for a SERS sensor and allows further in situ growth of AuNCs on its surface to build highly sensitive hot spots (electromagnetic mechanism, EM), promoting the durability and SERS performance of the substrate in complex environments. Therefore, the formed flexible MG/AuNCs-1 fiber exhibits a low detection limit of 1 × 10-11 M with a 2.01 × 109 enhancement factor (EFexp), signal repeatability (RSD = 9.80%), and time retention (remains 75% after 90 days of storage) for R6G molecules. Furthermore, the l-cysteine-modified MG/AuNCs-1 fiber realized the trace and selective detection of trinitrotoluene (TNT) molecules (0.1 µM) via Meisenheimer complex formation, even by sampling the TNT molecules at a fingerprint or sample bag. These findings fill the gap in the large-scale fabrication of high-performance 2D materials/precious-metal particle composite SERS substrates, with the expectation of pushing flexible SERS sensors toward wider applications.


Asunto(s)
Grafito , Nanopartículas del Metal , Trinitrotolueno , Grafito/química , Espectrometría Raman , Nanopartículas del Metal/química
11.
Small ; 19(25): e2208179, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36935369

RESUMEN

The realization of solar-light-driven CO2  reduction reactions (CO2 RR) is essential for the commercial development of renewable energy modules and the reduction of global CO2 emissions. Combining experimental measurements and theoretical calculations, to introduce boron dopants and nitrogen defects in graphitic carbon nitride (g-C3 N4 ), sodium borohydride is simply calcined with the mixture of g-C3 N4 (CN), followed by the introduction of ultrathin Co phthalocyanine through phosphate groups. By strengthening H-bonding interactions, the resultant CoPc/P-BNDCN nanocomposite showed excellent photocatalytic CO2 reduction activity, releasing 197.76 and 130.32 µmol h-1  g-1 CO and CH4 , respectively, and conveying an unprecedented 10-26-time improvement under visible-light irradiation. The substantial tuning is performed towards the conduction and valance band locations by B-dopants and N-defects to modulate the band structure for significantly accelerated CO2 RR. Through the use of ultrathin metal phthalocyanine assemblies that have a lot of single-atom sites, this work demonstrates a sustainable approach for achieving effective photocatalytic CO2 activation. More importantly, the excellent photoactivity is attributed to the fast charge separation via Z-scheme transfer mechanism formed by the universally facile strategy of dimension-matched ultrathin (≈4 nm) metal phthalocyanine-assisted nanocomposites.

12.
Ultrason Sonochem ; 94: 106325, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36801673

RESUMEN

In this work, different mass percent ratios of CoFe2O4 coupled g-C3N4 (w%-CoFe2O4/g-C3N4, CFO/CN) nanocomposites were integrated through a hydrothermal process for the sonocatalytic eradication of tetracycline hydrochloride (TCH) from aqueous media. The prepared sonocatalysts were subjected to various techniques to investigate their morphology, crystallinity, ultrasound wave capturing activity and charge conductivity. From the investigated activity of the composite materials, it has been registered that the best sonocatalytic degradation efficiency of 26.71 % in 10 min was delivered when the amount of CoFe2O4 was 25% in the nanocomposite. The delivered efficiency was higher than that of bare CoFe2O4 and g-C3N4. This enriched sonocatalytic efficiency was credited to the accelerated charge transfer and separation of e--h+ pair through the S-scheme heterojunctional interface. The trapping experiments confirmed that all the three species i.e. •OH, h+ and •O2- were involved in the eradication of antibiotics. A strong interaction was shown up between CoFe2O4 and g-C3N4 in the FTIR study to support charge transfer as confirmed from the photoluminescence and photocurrent analysis of the samples. This work will provide an easy approach for fabricating highly efficient low-cost magnetic sonocatalysts for the eradication of hazardous materials present in our environment.


Asunto(s)
Nanocompuestos , Tetraciclina , Catálisis , Antibacterianos , Agua , Luz
13.
J Tradit Chin Med ; 42(4): 595-603, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35848976

RESUMEN

OBJECTIVE: To evaluate Sterculia diversifolia stem bark and leaves for phytotoxic, genotoxic and enzymes inhibition potential. METHODS: Phytotoxic activity of both stem bark and leaves were screened using Lemna minor. The genotoxic activity of Sterculia diversifolia stem bark and leaves extracts were tested using comet assay protocol while enzyme inhibition activity of crude extract and various fractions of both stem bark and leaves were evaluated using acetyl cholinesterase, lipoxygenase, ß-glu-curonidase, urease, xanthine oxidase and carbonic anhydrase. RESULTS: Phytotoxic activity showed significant results in dose dependant manner in both stem bark (ethyl acetate and n-butanol) and leaves (ethyl acetate, n-butanol and n-hexane) fractions. In genotoxic activity, dichloromethane fraction showed significant activity followed by ethyl acetate fraction. Acetyl cholinesterease inhibitory activity showed significant results in both stem bark and leaves fractions, while significant lipoxygenase inhibition was shown by ethyl acetate, dichloromethane, crude extract and n-hexane fractions of both stem bark and leaves. ß-glucuronidase, urease and carbonic anhydrase inhibitory activity showed highly significant results in ethyl acetate fraction of both stem bark and leaves, while xanthine oxidase inhibition was shown by dichloromethane fraction of stem bark and leaves extracts. CONCLUSIONS: This study emphasizes the important phytotoxic, genotoxic and enzyme inhibition effects of Sterculia diversifolia stem bark and leaves. Hence, it is clear that Sterculia diversifolia stem bark and leaves possess phytotoxic, genotoxic and enzyme inhibitory agents.


Asunto(s)
Alcaloides , Anhidrasas Carbónicas , 1-Butanol , Daño del ADN , Humanos , Lipooxigenasas , Cloruro de Metileno , Corteza de la Planta , Extractos Vegetales/toxicidad , Hojas de la Planta , Ureasa , Xantina Oxidasa
14.
Chemosphere ; 307(Pt 1): 135717, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35863405

RESUMEN

In this work, NiFe2O4/g-C3N4 heterostructure was prepared and used for the photocatalytic decomposition of tetracycline hydrochloride antibiotic and for inactivation of E. coli bacteria. The fabricated NiFe2O4/g-C3N4 composite displayed enhanced ability for photodegradation of organic pollutants and disinfection activities compared to the bare samples, because of the enhancement of visible light absorbance, heterojunction formation and photo-Fenton process. The optimized sample 10%-NiFe2O4/g-C3N4 has photodegraded 94.5% of tetracycline hydrochloride in 80 min. The active species trapping experiments revels that ·O2-, h+ and •OH are key decomposing species participated in the antibiotic degradation. It is hoped that the present study will provide a better understanding to fabricate efficient photocatalysts for the decomposition of organic pollutants and disinfection of bacteria.


Asunto(s)
Contaminantes Ambientales , Tetraciclina , Antibacterianos/química , Antibacterianos/farmacología , Catálisis , Escherichia coli , Luz , Tetraciclina/química , Tetraciclina/farmacología
15.
Adv Sci (Weinh) ; 9(2): e2102530, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34859614

RESUMEN

Artificial Z-scheme, a tandem structure with two-step excitation process, has gained significant attention in energy production and environmental remediation. By effectively connecting and matching the band-gaps of two different photosystems, it is significant to utilize more photons for excellent photoactivity. Herein, a novel one-photon (same energy-two-photon) Z-scheme system is constructed between rGO modified boron-nitrogen co-doped-WO3 , and coupled CdSe quantum dots-(QDs). The coctalyst-0.5%Rhx Cr2 O3 (0.5RCr) modified amount-optimized sample 6%CdSe/1%rGO3%BN-WO3 revealed an unprecedented visible-light driven overall-water-splitting to produce ≈51 µmol h-1 g-1 H2 and 25.5 µmol h-1 g-1 O2 , and it remained unchanged for 5 runs in 30 h. This superior performance is ascribed to the one-photon Z-scheme, which simultaneously stimulates a two photocatalysts system, and enhanced charge separation as revealed by various spectroscopy techniques. The density-functional theory is further utilized to understand the origin of this performance enhancement. This work provides a feasible strategy for constructing an efficient one-photon Z-scheme for practical applications.

16.
Front Chem ; 9: 797738, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34957051

RESUMEN

Amorphous CuO is considered as an excellent cocatalyst, owing to its large surface area and superior conductivity compared with its crystalline counterpart. The current work demonstrates a facile method to prepare amorphous CuO, which is grown on the surface of graphitic carbon nitride (g-C3N4) and is then applied for the photocatalytic degradation of tetracycline hydrochloride. The prepared CuO/g-C3N4 composite shows higher photocatalytic activities compared with bare g-C3N4. Efficient charge transfer between g-C3N4 and CuO is confirmed by the photocurrent response spectra and photoluminescence spectra. This work provides a facile approach to prepare low-cost composites for the photocatalytic degradation of antibiotics to safeguard the environment.

17.
Membranes (Basel) ; 11(6)2021 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-34204185

RESUMEN

In this study, nano-TiO2 sulfonated with 1,3-propane sultone (STiO2) was incorporated into the chitosan (CS) matrix for the preparation of CS/STiO2 nanocomposite membranes for fuel cell applications. The grafting of sulfonic acid (-SO3H) groups was confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis and energy-dispersive X-ray spectroscopy. The physicochemical properties of these prepared membranes, such as water uptake, swelling ratio, thermal and mechanical stability, ion exchange capacity and proton conductivity, were determined. The proton conducting groups on the surface of nano-TiO2 can form continuous proton conducting pathways along the CS/STiO2 interface and thus improve the proton conductivity of CS/STiO2 nanocomposite membranes. The CS/STiO2 nanocomposite membrane with 5 wt% of sulfonated TiO2 showed a proton conductivity (0.035 S·cm-1) equal to that of commercial Nafion 117 membrane (0.033 S·cm-1). The thermal and mechanical stability of the nanocomposite membranes were improved because the interfacial interaction between the -SO3H group of TiO2 and the -NH2 group of CS can restrict the mobility of CS chains to enhance the thermal and mechanical stability of the nanocomposite membranes. These CS/STiO2 nanocomposite membranes have promising applications in proton exchange membrane fuel cells.

18.
Environ Res ; 195: 110742, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33515579

RESUMEN

Chlorophenols are very important environmental pollutants, which have created huge problems for both aquatic and terrestrial lives. Therefore, their removal needs urgent, effective, and advanced technologies to safeguard our environment for future generation. This review encompasses a comprehensive study of the applications of chlorophenols, their hazardous effects and photocatalytic degradation under light illumination. The effect of various factors such as pH and presence of different anions on the photocatalytic oxidation of chlorophenols have been elaborated comprehensively. The production of different oxidizing agents taking part in the photodegradation of chlorophenols are given a bird eye view. The photocatalytic degradation mechanism of different chlorophenols over various photocatalyts has been discussed in more detail and elaborated that how different photocatalysts degrade the same chlorophenols with the aid of different oxidizing agents produced during photocatalysis. Finally, a future perspective has been given to deal with the effective removal of these hazardous pollutants from the environment.


Asunto(s)
Clorofenoles , Catálisis , Oxidantes , Oxidación-Reducción , Fotólisis
19.
J Asian Nat Prod Res ; 23(9): 899-905, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32654513

RESUMEN

One new coumarin (stercularin), along with eleven known compounds, was isolated for the first time from ethyl acetate fraction of Sterculia diversifolia. The structures of isolated compounds were characterized by spectroscopic techniques such as EIMS, 1H-NMR and 13C-NMR. Compound 1 showed significant cytotoxicity by brine shrimp lethality assay (LD50: 8.00 µg/ml) and PC-3 cell lines protocol (IC50: 3.92 ± 0.20 µg/ml), respectively.


Asunto(s)
Sterculia , Estructura Molecular , Extractos Vegetales
20.
Sci Total Environ ; 746: 141291, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32763611

RESUMEN

In this study, we have successfully synthesized honeycomb-like self-assembled structure of TiO2 modified ZnO/SnO2 nanostructure via co-precipitation method with exceptional high degradation activities for 2,4-dichlorophenol (2,4-DCP) and bisphenol A (BPA) pollutants. The as-prepared samples were calcined in tube furnace at high elevated temperature (700, 800 and 900 °C) for 1 h. Among the TiO2 modified samples, ZST10-700 showed higher charge separation as demonstrated from surface photovoltage spectroscopy, photoluminance and electrochemical curve. Surface morphology, crystallinity, optical property and different functional groups in the samples were determined with SEM, EDX, XRD, UV-Vis DRS and FTIR, respectively. Interestingly, 72% and 58% photocatalytic degradation efficiencies were achieved with optimized ZST10-700 for 2,4-DCP and BPA, respectively. In comparison, the pure ZS-700 only showed 36% and 29% photocatalytic degradation efficiencies, respectively. The improved photocatalytic degradation efficiencies of the optimized ZST10-700 are mainly due to improved charge separation and prolonged charge lifetime. It was further verified that by increasing calcination temperature, the photocatalytic activity decreased, and this is attributed to the formation of photo-inactive phases like Zn2SnO4 and ZnTiO3. We believe that this work will provide an effective strategy to construct ternary heterojunction for the elimination of pollutants.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...