4-nitrophenol Research Articles

Anti-perovskite Co4N nanowhisker rooted on nickel foam to activate peroxymonosulfate for robust degradation of p-nitrophenol via non-radical dominant pathway

The fabrication of metal-nitrogen functional centers that possess features of easy recovery and high performance for degrading organic pollutants through activating peroxymonosulfate (PMS) represents a significant challenge. In this study, we present the synthesis of an anti-perovskite Co4N architecture in a granular nanowhisker form rooted on three-dimensional nickel foam (Co4N/NF) using a hydrothermal method followed by thermal nitridation with ammonia from urea pyrolysis. The resulting Co4N/NF exhibits exceptional efficiency in degrading p-nitrophenol (PNP), achieving a degradation efficiency of 97.8 % and a rate constant of 0.204 min−1 within 20 min. The unique nanostructure of granular nanowhisker Co4N on NF provides abundant surface sites for activating PMS and enhances mass/electron transport, contributing to its excellent degradation capabilities. Additionally, the Co4N/NF material exhibits outstanding stability, easy separation and recovery features, maintaining a degradation efficiency of 90.2 % within 20 min even after five cycles. This study lays the groundwork for developing advanced anti-perovskite nitrides on a 3D substrate to activate PMS for environmental contaminant remediation.

Catalytic green synthesis of Tin(IV) oxide nanoparticles for phenolic compounds removal and molecular docking with EGFR tyrosine kinase

In this study, tin dioxide nanoparticles (SnO2 NPs) were successfully synthesized through an eco-friendly method using basil leaves extract. The fabricated SnO2 NPs demonstrated significant adsorption capabilities for phenol (PHE), p-nitrophenol (P-NP), and p-methoxyphenol (P-MP) from water matrices. Optimal conditions for maximum removal efficiency was determined for each phenolic compound, with PHE showing a remarkable 95% removal at a 3 ppm, 0.20 g of SnO2 NPs, pH 8, and 30 min of agitation at 35 °C. Molecular docking studies unveiled a potential anticancer mechanism, indicating the ability of SnO2 NPs to interact with the epidermal growth factor receptor tyrosine kinase domain and inhibit its activity. The adsorption processes followed pseudo-second order kinetics and Temkin isotherm model, revealing spontaneous, exothermic, and chemisorption-controlled mechanisms. This eco-friendly approach utilizing plant extracts was considered as a valuable tool for nano-sorbent production. The SnO2 NPs not only exhibit promise in water treatment and also demonstrate potential applications in cancer therapy. Characterization techniques including scanning electron microscopy, UV–visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy (XRD), and energy-dispersive X-ray spectroscopy (EDAX) provided comprehensive insights into the results.

Understanding the synergistic interactions between photo-Fenton and photocatalytic reactions in hemin-anchored SnO2

Sensitization of wide-gap metal oxides by the porphyrins has been promising to utilize the major fraction of solar light for photocatalytic reactions. In this context, rutile-SnO2 was anchored with hemin complex and their performance was evaluated for the 4-nitro phenol (4-NP) degradation under UV/visible light. Driven by the significant interactions between -COOH and surface -OH functional groups of hemin and SnO2 respectively, a new linkage O=CO-Sn was formed at the interface, which was vital for charge carrier transfer between them. Both X-ray diffraction studies and scanning electron microscope analysis confirmed that the surface hemin adsorption did not alter the crystal structure and the morphology of pristine SnO2. The light absorption properties revealed a red shift in the optical response of the composite, which facilitated the photocatalytic reactions to operate under visible light. The electrochemical and photoluminescence measurements collectively attested to the enhanced charge carrier separation in the composite compared to pure SnO2. The synergism arising from the photo-Fenton and photocatalytic reactions was derived from the cyclic reactions of Fe(II)/Fe(III) and oxidation of hydroxyl radicals by the valence band holes of SnO2 with H2O2 under UV light. In contrast, the sensitization process resulted in electron transfer from the excited state of hemin to the conduction band (CB) of SnO2 under visible light. Such distinct mechanistic pathways by the metal oxide-porphyrin composite would be promising for wastewater purification under UV–visible light region in near future.

Enhanced degradation of para-nitrophenol during the UV/chlorine process with the addition of Fe(III): Performance, reaction mechanisms, and DBPs formation

Para-nitrophenol (PNP) enters aquatic environments through wastewater discharge, potentially threatening ecological security and public health. This work investigated the enhanced degradation of PNP in wastewater during the UV/chlorine process with the addition of Fe(III) (UV/chlorine/Fe(III)). The UV/chlorine/Fe(III) process (61.85 %) exhibited higher performance in PNP degradation in 10 min compared to the UV/chlorine process (40.00 %) because the synergistic effect of Fe(III) and free chlorine enhanced hydroxyl radicals (OH) and reactive chlorine species (RCSs) production. Furthermore, OH and RCSs were identified as the primary contributors to degrade PNP during the UV/chlorine/Fe(III) process, and their corresponding contributions accounted for 40.09 % and 37.10 %, respectively. Besides, the degradation efficiencies of PNP were promoted by increasing the dosages of Fe(III) and free chlorine and declined by increasing pH and PNP concentration. Also, Cl− could promote PNP degradation, while SO42− and HCO3− inhibited it. Then, the reaction mechanisms of PNP degradation during the UV/chlorine/Fe(III) process were proposed based on the identified transformation products (TPs) and the density functional theory (DFT) calculation. Meanwhile, PNP, TPs, and other possible intermediate products presented different ecotoxicity. Finally, the formation and toxicity of disinfection by-products (DBPs) with different Fe(III) concentrations, chlorine dosages, initial pHs, and PNP concentrations were explored. Overall, the obtained findings can provide deep insights into the mechanisms of PNP degradation and a new approach to enhancing PNP degradation in wastewater.

Catalytic and Capacitive Properties of Hierarchical Carbon–Nickel Nanocomposites

Hierarchically graphitic carbon that contained nickel nanoparticles (HGC-Ni (1), (2), and (3)) were prepared by the pyrolysis of three metal complexes as follows: nickel 2,2′-biyridine dichloride, nickel terephthalate 2,2′-bipyridine, and nickel phenanthroline diaqua sulfate, respectively, in the presence of anthracene or pyrene. SEM indicated that the structure of the HGC-Ni samples consisted of nickel nanoparticles with a diameter of 20–500 nm embedded in a thin layer of a hierarchical graphitic carbon layer. The EDAX of HGC-Ni indicated the presence of nickel, carbon, and nitrogen. Chlorine, oxygen, and sulfur were present in (1), (2), and (3), respectively, due to the differences in their complex precursor type. XRD indicated that the nanoparticles consisted of Ni(0) atoms. The turnover frequency (TOF) for the reduction of p-nitrophenol (PNP) increased for catalysts HGC-Ni (3), (2), and (1) and were 0.0074, 0.0094, and 0.0098 mg PNP/mg catalyst/min, respectively. The TOF for the reduction of methyl orange (MO) increased for catalysts (3), (1), and (2) and were 0.0332, 0.0347, and 0.0385 mg MO/mg catalyst/min, respectively. Thus, nickel nano-catalysts (1) and (2) provided the highest performance compared to the nano-catalysts for the reduction of PNP and MO, respectively. The first-order rate constant (min−1) of HGC-Ni (3), with respect to the reduction of PNP, was 0.173 min−1, while the first-order rate constant (min−1) for the reduction of MO by HGC-Ni (1) was 0.404 min−1. HGC-Ni (3) had the highest number of cycles with respect to PNP (17.9 cycles) and MO (22.8 cycles). The catalysts were regenerated efficiently. HGC-Ni exhibited remarkable electrochemical capacitance characteristics in the present study. This material achieved a notable specific capacitance value of 320.0 F/g when measured at a current density of 2 A/g. Furthermore, its resilience was highlighted by its ability to maintain approximately 86.8% of its initial capacitance after being subjected to 2500 charge and discharge cycles. This finding suggests that this HGC-Ni composite stands out not only for its high capacitive performance but also for its durability, making it an attractive and potentially economical choice for energy-storage solutions in various technological applications.

3D Superclusters with Hybrid Bioinks for Early Detection in Breast Cancer.

The surface-enhanced Raman scattering (SERS) technique has garnered significant interest due to its ultrahigh sensitivity, making it suitable for addressing the growing demand for disease diagnosis. In addition to its sensitivity and uniformity, an ideal SERS platform should possess characteristics such as simplicity in manufacturing and low analyte consumption, enabling practical applications in complex diagnoses including cancer. Furthermore, the integration of machine learning algorithms with SERS can enhance the practical usability of sensing devices by effectively classifying the subtle vibrational fingerprints produced by molecules such as those found in human blood. In this study, we demonstrate an approach for early detection of breast cancer using a bottom-up strategy to construct a flexible and simple three-dimensional (3D) plasmonic cluster SERS platform integrated with a deep learning algorithm. With these advantages of the 3D plasmonic cluster, we demonstrate that the 3D plasmonic cluster (3D-PC) exhibits a significantly enhanced Raman intensity through detection limit down to 10-6 M (femtomole-(10-17 mol)) for p-nitrophenol (PNP) molecules. Afterward, the plasma of cancer subjects and healthy subjects was used to fabricate the bioink to build 3D-PC structures. The collected SERS successfully classified into two clusters of cancer subjects and healthy subjects with high accuracy of up to 93%. These results highlight the potential of the 3D plasmonic cluster SERS platform for early breast cancer detection and open promising avenues for future research in this field.

Novel Pharmaceutical Cocrystals of Tegafur: Synthesis, Performance, and Theoretical Studies.

Tegafur (TF) is one of the most important clinical antitumor drugs with poor water solubility, severely reducing its bioavailability. This work develops new cocrystals to improve the solubility of TF and systematically investigates the intermolecular interactions to provide new insights into the formation of cocrystal and changes in physicochemical properties. In this paper, two new 1:1 cocrystals of TF with 2,4 dihydroxybenzoic acid (2,4HBA) and p-nitrophenol (PNP) were synthesized. The cocrystal products were identified and characterized by various solid state analysis techniques. And the high performance liquid chromatography (HPLC) was conducted to determine the solubility and dissolution rate of TF and cocrystals. Moreover, the quantum chemistry calculations of crystal structure provided theoretical support for the results. Compared with pure TF, the solubility and dissolution rate of TF-2,4HBA is significantly increased in a pH 6.8 buffer at 37°C. Under accelerated storage conditions (40°C, 75% RH), all cocrystal exhibits excellent stability over 8weeks. Hirshfeld surface (HS) analysis, atoms in molecules (AIM) analysis, interaction region indicator (IRI) analysis, molecular electrostatic potential surface (MEPS) analysis and frontier molecular orbital (HOMO-LUMO) analysis were integrated to understand the hydrogen bonding interaction more comprehensively. The simulation results are in good agreement with the experimental data. The results show that the analysis of physical and chemical properties of TF-PNP cocrystal and TF crystal by quantum chemistry method is reliable at molecular level. These results are helpful to provide guiding methods in the cocrystal development and theoretical study of tegafur.

Enhancing the Fenton-like degradation of organic contaminants with silicate-iron in aquifer media by ascorbic acid

In this study, silicate-iron (FeSi-ox, FeAlSi-ox) in aquifer media was utilized as an original iron source in groundwater to systematically investigate the effects of ascorbic acid on the degradation of p-nitrophenol (PNP) in the in-situ Fenton-like reaction. Silicate-iron in the aquifer media increased the PNP removal rate by activing H2O2 following the addition of ascorbic acid. The optimal removal rate of PNP was nearly 89% within 40 h, which was 6.8 times higher than that without ascorbic acid. In addition to PNP, some other common pollutants, such as nitrobenzene, trichloromethane, and trichloroethylene, can also be effectively degraded and mineralized. The suitable pH range for the silicate-iron Fenton-like system with ascorbic acid was 5–9, indicating that it is feasible in near-neutral or alkaline groundwater environments. The main functional free radicals were hydroxyl free radicals (•OH), which were produced slowly but continuously. In this novel Fenton-like system, dissolved Fe played a major role in H2O2 decomposition and pollutant degradation. The main mechanism underlying the increased strength of the degradation was the ability of ascorbic acid to facilitate the dissolution of surface Fe from aquifer media and accelerate the cycling of Fe(Ⅲ)/Fe(Ⅱ) in the liquid phase.

Catalytic Reductive Degradation of 4-Nitrophenol and Methyl orange by Novel Cobalt Oxide Nanocomposites

Cobalt oxide nanocomposites were synthesized and used for the catalytic degradation of 4-nitrophenol (4-NP) and methyl orange (MO). Cobalt oxide nanocomposites PyroHAB9 was prepared by heating cobalt acetylacetonate complex HAB9 at 300 °C, while PyroHAB19 was prepared by heating cobalt acetylacetonate–carboxymethyl cellulose complex at 300 °C. FTIR indicated the presence of Co3O4 species, while Raman spectrum indicated the presence of graphite in PyroHAB19. The SEM morphology of nanocomposites exhibited irregular spherical shape nanoparticles with sizes ranging between 20 to 60 nm. Additionally, nanowires were also seen in HAB19. Also, 2Ɵ peaks in PXRD revealed the formation of Co3O4 in HAB19. Cyclic voltammetry indicated enhanced electrochemical redox activity of HAB19. The structures of the nanocomposites were related to their catalytic activities. The turnover frequency (TOF) values of the catalytic reduction of p-nitrophenol (P-NP) and methyl orange (MO) were greater for HAB19 compared to HAB9 nano-catalysts. Also, the TOF values of the catalytic reduction of MO were greater than that of P-NP by both nano-catalysts. It is obvious that the rate constants of catalytic reductions for MO by metal oxide nanocomposites were greater than the corresponding rate constants for PNP. The highest rate constant was found for PyroHAB19 in MO reduction.

Mycogenic synthesis of iron nanoparticles using thermophilic mould Myceliophthora thermophila and their applicability in environmental remediation

Culture extract of thermophilic mould Myceliophthora thermophila BJTLRMDU7 played important role in the green synthesis of iron nanoparticles (FeNPs) using ferrous sulphate (FeSO4). The mould was grown in potato dextrose broth (PDB) at 45 °C and 200 rpm for 72 h. A colour change from transparent to reddish brown showed the synthesis of FeNPs due to the surface plasmon resonance by the fungal culture extract. The process for the synthesis of nanoparticles was optimized using different reaction conditions. Biogenic iron nanoparticles were synthesized maximally at 50 °C and pH 5.0 after 24 h using 2 mM salt solution and one ml culture extract. Furthermore, formation of iron nanoparticles was significantly accelerated in the presence of light. The absorption peak was maximum around 250–350 nm in UV–vis spectrum. The absorption peaks of Fourier-transform infrared spectroscopy (FTIR) at 619.99 cm−1, 793.57 cm−1, 882.32 cm−1, 1121.46 cm−1, 1627.71 cm−1, 2923.17 cm−1 and 3430.70 cm−1, indicated functional groups of active biomolecules involved in the synthesis of FeNPs. Atomic force microscopy (AFM) images of green synthesized iron nanoparticles indicated the average size of 80 nm, while X-ray diffraction (XRD) data revealed the crystalline nature of FeNPs. These FeNPs efficiently reduced p-nitrophenol (PNP) into p-aminophenol (PAP), which was further confirmed by thin layer chromatography. Biogenic FeNPs showed 96 and 35 % decolourization of bromphenol blue and malachite green, respectively. Further, addition of H2O2 enhanced the decolourization of malachite green up to 96 %. Biogenic FeNPs synthesized from culture extract of a thermophilic mould have been found effective in remediation of environmental pollutants released from various industries.

Development of sensitive electrochemical sensor Ni@CuO/rGO/PtE for the determination of 4-Nitrophenol: An electroanalytical approach for pollution control

Para nitrophenol, generally known as 4-nitrophenol (4-NP), is a well-known organic pollutant that is being broadly discharged into the environment and poses several health threats to humans. For the sensitive and selective screening of 4-NP, a new electrochemical sensor based on Ni@CuO/rGO/PtE has been developed. The XRD analysis revealed excellent crystalline structure with an average size of 47.3 nm for Ni@CuO/rGO nanocomposite. SEM and HR-TEM characterization evaluated the successful incorporation of Ni and CuO into the GO sheets. The EDX analysis confirmed the prepared nanocomposite's exceptional purity and percent elemental composition. The prepared material was casted on the surface of bare PtE via the drop-casting method, which resulted in the uniform deposition of Ni@CuO/rGO over the PtE's surface. The fabricated sensor Ni@CuO/rGO/PtE manifested excellent response for 4-NP under optimized conditions, e.g., scan rate 110 mV/s, PBS electrolyte acidic pH -5, and under potential window between (−0.3 to −1.2 V). A broad linear concentration range was optimized from 0.09 to 105 μM to get a linear calibration curve of 4-NP. The LOD and LOQ of the proposed method were calculated as 0.0054 μM and 0.018 μM, which is almost lower than the reported sensor for 4-NP. The analytical applicability of Ni@CuO/rGO/PtE was tested in tap water and river water samples. The fabricated sensor exhibited acceptable recoveries for 4-NP in water samples, highlighting the proposed sensor's good reliability in real samples.

Reusable porous chromium- zinc oxide nano-sheets for efficient detoxification of xenobiotics through integrated advanced oxidation water clean-up process

An integrated approach of acoustic, ultraviolet, and sunlight-driven Advanced Oxidation Process (AOP) is an excellent choice in the quest for a water-cleaning process. This research delves into the realization of chromium-doped zinc oxide (Cr/ZnO) nanopores as a low energy, eco-friendly, efficient, and exhibiting stable photocatalysis for the AOP process. Ultrasonic-aided co-precipitation technique was used for the synthesis of porous Cr-ZnO nanostructures. X-ray diffraction patterns and FTIR spectra of the synthesized samples revealed that chromium ions were effectively intruded into the ZnO lattice. Tauc's equation and Kubella Munk plots have explored that the incorporation of Cr dopants in ZnO reduces the optical band energy. The formation of porous structures was evinced in SEM, TEM, HRTEM, and BET studies. The presence of abundant mesoporous structures was confirmed by the adsorption/desorption isotherms of type IV hysteresis. The antimicrobial efficacy of Cr-ZnO against aqueous bacteria, Staphylococcus aureus, and Escherichia coli was comparatively as effective as the control. The integrated AOP approach enhances the electron trapping characteristics of nanoporous Cr-ZnO catalysts to generate self-sustained in-situ reactive oxygen species on the aqueous matrix. In the current research, methylene orange and nitro phenol were detoxified up to 99 % and 98.2 %, and their half-life degradation rate constant was 22 min and 26 min, respectively. The total organic contaminants (TOC) test on the resultant treated water has confirmed the effective detoxification of xenobiotic molecules and the possibility of reusing the treated water. The ecotoxicology research using treated water on flora and primary aquatic microfauna has supported the possibility of practical utilization of Cr-ZnO in harmless environmental adaptation in the foreseeable future.

R-GO coated magnetic high entropy alloy/oxide nanocomposites as highly efficient Fenton and photo-Fenton catalysts

To utilize the synergistic effect of high entropy alloy, high entropy oxide and r-GO (reduced graphene oxide), we prepared r-GO coated nanocomposites comprising bcc high entropy alloy/spinel high entropy oxide (H730) and bcc high entropy alloy/hexagonal high entropy oxide (H725), encompassing elemental constituents such as Aluminum (Al), Chromium (Cr), Manganese (Mn), Iron (Fe), and Cobalt (Co). The samples were meticulously synthesized using the sol-gel technique followed by subsequent calcination at a temperature of 700 °C under nitrogen or air atmospheres. The assessment through X-ray diffraction and electron diffraction methodologies conclusively confirmed the successful formation of nanocomposite structures. The electron microscopy and Raman spectroscopy confirmed the r-GO coating over both the composites. The saturation magnetization values of 32 and 10 emu/g were noticed at 30 kOe for H730 and H725 samples, respectively. In-depth analysis using X-ray photoelectron spectroscopy revealed the coexistence of diverse oxidation states within the constituent elements of the samples. Notably, the H730 nanocomposite exhibited superior catalytic efficacy in comparison to its H725 counterpart for the degradation of p-nitrophenol (PNP) under both Fenton and photo-Fenton reaction conditions. Impressively, complete degradation of PNP was achieved within a remarkably short span of 18 min. Furthermore, the H730 nanocomposite alongwith stronger magnetic attributes, demonstrated a notable 86 % degradation efficiency even after undergoing five consecutive cycles.

Effect of Interfacial Action on the Generation and Transformation of Reactive Oxygen Species in Tripolyphosphate-Enhanced Heterogeneous Fe3O4/O2 Systems.

It has been reported that tripolyphosphate (TPP) can enhance the oxygenation of natural Fe(II)-containing minerals to produce reactive oxygen species (ROS). However, the molecular structure of the TPP-Fe(II) mineral surface complex and the role of this complex in the generation and transformation of ROS have not been fully characterized. In the present study, a heterogeneous magnetite (Fe3O4)/O2/TPP system was developed for the degradation of p-nitrophenol (PNP). The results showed that the addition of TPP significantly accelerated the removal of PNP in the Fe3O4/O2 system and extended the range of effective pH to neutral. Experiments combined with density functional theory calculations revealed that the activation of O2 mainly occurs on the surface of Fe3O4 induced by a structural Fe(II)-TPP complex, where the generated O2•- (intermediate active species) can be rapidly converted into H2O2, and then the •OH generated by the Fenton reaction is released into the solution. This increases the concentration of •OH produced and the efficiency of •OH produced relative to Fe(II) consumed, compared with the homogeneous system. Furthermore, the binding of TPP to the surface of Fe3O4 led to stretching and even cleavage of the Fe-O bonds. Consequently, more Fe(II)/(III) atoms are exposed to the solvation environment and are available for the binding of active O2 and O2•-. This study demonstrates how common iron minerals and O2 in the natural environment can be combined to yield a green remediation technology.

A Type of Conjugated Fuse Heterocyclic Schiff Base Colorimetric andFluorescent Chemosensors for Selective Detection of Picric acid (PA)

: A series of Schiff base chemosensors (M1, M2 and M3) were designed and synthesized based on conjugated fuse heterocyclic aldehyde thiosemicarbazone. Optical properties of fluorescent probes M1, M2, and M3 toward various nitro explosives 2,4-dinitrotoluene (DNT), o-nitrophenol (ONP), p-nitrophenol (PNP), phenol (PhOH) and nitromethane (NM) were investigated, M1, M2, and M3 could selectively recognize PA with an obvious color change and fluorescence quenching, even in the presence of other coexistence nitro explosives. The detection limit of M1, M2, and M3 were 1.18and#215;10-7 M, 1.13and#215;10-7 M, 1.09and#215;10-7 M, respectively.

Recent advancements in pesticide mitigation using engineered Escherichia coli strains

Pesticides have considerably increased agricultural output, but their overuse presents serious threats to human health, food safety, and the environment. Alarmingly, only around 1% of pesticides used reach their intended pests, with the remainder polluting soil, water, and air. This causes broad environmental contamination and negative consequences on non-target animals, including people. Top pesticide-consuming countries, including China, the United States, and Brazil, confront considerable issues due to residual pesticide buildup. Recent biotechnology developments provide intriguing pesticide mitigation strategies. Engineered Escherichia coli (E. coli) strains have developed as very efficient bioremediation agents. These genetically engineered microbes are intended to convert hazardous chemicals into harmless metabolites. E. coli strains are tailored for increased expression of pesticide-degrading genes using modern genetic and metabolic engineering, dramatically enhancing their ability to break down hazardous chemicals. Studies have shown that modified E. coli may degrade persistent pesticides such as Paraoxon and p-nitrophenol (PNP), turning them to harmless molecules. These bacteria may reach great densities, making them ideal for large-scale detoxifying operations. Furthermore, recombinant DNA technology enables the development of E. coli strains with several copies of degradation genes, which improves their bioremediation capacities. Despite these advances, obstacles persist, including biosafety issues and the need for regulatory supervision. Ongoing research is critical for addressing these concerns and developing safer, more sustainable agriculture techniques. Engineered E. coli strains represent a substantial advancement in pesticide mitigation, providing a feasible approach for reducing environmental pollution and protecting human health.

Formation of nitro(so) by-products of concern during the treatment of phenolic compounds by the hydroxylamine-enhanced Fe(ii)/peroxymonosulfate process

The transformation pathway of hydroxylamine and the formation mechanism of nitro(so) by-products during the treatment of phenols using the Fe(ii)/peroxymonosulfate/hydroxylamine system are elaborated.

Ultrafast electron shuttling suppresses the energy transfer process in Mn-doped CsPbCl3 nanocrystals.

Taking advantage of the slow exciton-to-dopant energy transfer process, we dissociated the exciton in Mn-doped perovskite via ultrafast electron shuttling to a surface adsorbed 4-nitro phenol molecule. The observed ultrafast electron transfer process is competitive to the ultrafast exciton scattering process (∼140 fs) to the continuum states via optical phonons, but three-orders faster than the exciton-to-Mn energy transfer timescale.

Preparation of an imprinted monolith for field simultaneously selective separation and enrichment of nitrophenols and lead (II) ion in water samples

Imprinted materials have gained significant attention due to its highly specific recognition performance. However, there is no study that using molecule and ion as mixed templates to prepare hybrid imprinted material for simultaneously selective separation and enrichment of molecules and ion. Here, a new strategy employing organic molecule and heavy metal ion as mixed templates to prepare imprinted material was proposed. 2,4-Dinitrophenol (2,4-DNP) and Pb2+ were selected as model templates to in-situ synthesize adsorbent based on imprinted monolith (AIM) in pipette tip. The obtained AIMs were used as the extraction medium of home-made multiple channels in-tip microextraction device (MCMD) for field simultaneously selective entrapment of nitrophenols (NPs) and Pb2+. The selection of functional monomers was well verified with Density function theory. Under the optimal fabrication conditions, the AIM displayed high specific recognition capability towards 2,4-DNP and Pb2+ with imprinted factors 7.31 and 5.20, respectively, and corresponding adsorption capacities were as high as 27.8 mg/g and 20.3 mg/g, respectively. The practicality of proposed AIM/MCMD was evaluated by simultaneously on-site selective capture of NPs and Pb2+ in various environmental waters prior to quantification with HPLC (for NPs) and atomic absorption spectrometry (for Pb2+). Results well evidence that the proposed strategy is feasible in the preparation of imprinted polymer for simultaneously specific extraction of molecules and metal ion, and the developed AIM/MCMD is a useful field sample preparation method for reliable quantification of NPs and Pb2+ in aqueous samples.

Dual role of silk fabric functionalized with polymer/GO-tungsten oxide nanocomposites as superwettable membranes and photocatalysts for removing dye contaminants and emulsion separation

BackgroundWastewater containing hazardous dye contaminants has aroused significant concern and poses a great challenge to membrane technology. Herein, a novel bio-inspired silk fabric membrane modified with L-histidine functionalized polyglycidyl methacrylate composited with graphene oxide and tungsten oxide (amino-PGMA/GO-WO2.72) was successfully produced to treat wastewater contaminants. MethodsAn urchin-like WO2.72 nanoparticle is synthesized using the hydrothermal method. The synthesized WO2.72 nanoparticles are composited with an amino-functionalized PGMA/GO via dispersion polymerization techniques. Finally, a flexible membrane is created by dip-coating silk fabric in the amino-PGMA/GO-WO2.72 nanocomposite solution. Significant findingsThe fabricated membrane showed excellent superhydrophilicity, underwater superoleophobicity, and outstanding performance in separating methylene blue (MB) dye-mixed emulsions under gravity with a high permeation flux of about 1690 ± 40 L m−2 h−1. The amino-PGMA/GO-WO2.72 modified silk fabric membrane showed remarkable stability, allowing the membrane to withstand a high separation efficiency of 99 %. Furthermore, the photo-responsive ability of the heterojunction GO-WO2.72 catalyst materials present in the modified membrane can lead to the reduction of toxic nitro phenols, degradation of various dyes and textile effluents wastewater with high photodegradation efficiency under UV–-visible and solar light irradiation.