Chemical Papers最新文献

The exploration of renewable energy in the twenty-first century emerged as the world-leading movement to support energy sustainability, leading to the paramount necessity for energy storage systems (ESSs). The porous carbon-derived electrode has been a long-pursued aim in supercapacitor applications, which feature their availability, renewability, environmental friendliness, rapid ion transport, and tunable surface chemistry. In this regard, chemical activation is one of the most highly praised and compatible strategies for synthesizing porous carbon in energy storage applications. Nevertheless, the most challenging issue to reconcile has been using environmentally hazardous, unsustainable activators. NaNH₂ emerges as a greener solution to the synthesis of porous carbon. Additionally, it presents as a dual-function activator, serving as a nitridation and activating agent. This dual role promotes the development of micropores and mesopores in the pore architecture and active sites for effective ion transport, highlighting the critical facets in the fabrication of supercapacitor electrode materials. Herein, this paper discussed the promising use of NaNH₂-activated porous carbon in electrochemical applications that covered the synthesis of porous carbon to the proposed activation mechanism, the impact of variations in design parameters, and the electrochemical properties of the resultant porous carbon. Ultimately, the recent challenges and future outlooks were comprehensively highlighted.

This study investigated the efficacy of utilizing eggshells and their pyrolyzed derivatives, within the temperature range of 400–800 °C, as adsorbents for ciprofloxacin (CIP) removal. Experimental data were analyzed using various machine learning (ML) algorithms, viz. linear regression, random forest, support vector machines, decision trees, and k-nearest neighbor to predict performance. Results demonstrated that pyrolyzed eggshells at 600 °C (PES-600) exhibited the highest CIP removal rate (86.06 ± 2.25%). Optimal performance was consistently observed at an initial CIP concentration of 125 mg/L, with the order of PES-600 > PES-500 > PES-400 > PES-700 > eggshells > PES-800. Adsorption capacity peaked at pH 5 (5.84 ± 0.1 mg/g), attributed to interactions including hydrogen bonding, π–π interaction, and ion exchange. Scanning electron microscope images revealed that PES-600 had the highest number of pores, resulting in a smoother surface post-adsorption. Langmuir isotherm model fitting was best for ES, PES-700, and PES-800, while Freundlich isotherm was suitable for PES-400, PES-500, and PES-600. PES-600 showed the best fit with the pseudo-second-order kinetic model. Characterization analysis highlighted the significance of functional groups like C = O, C = C, and –CH groups in aromatic rings. ML algorithms demonstrated remarkable performance with an accuracy level of 90.28%. In conclusion, pyrolyzed eggshells can effectively remove ciprofloxacin (CIP) from wastewater, with optimal performance predicted by the random forest machine learning algorithm when considering real environmental factors.

Several novel quinazoline derivatives bearing phenolic hydroxyl moiety (2–7) have been produced with good yields and screened for biological activities. All the title compounds were characterized using spectroscopic techniques such as ¹H NMR, ¹³C NMR, FTIR, and HRMS. Then, the anti-browning effects of synthesized quinazoline derivatives were investigated in vitro. The IC₅₀ values for molecules 2–7 were calculated as 0.085, 1.145, 0.106, 6.86, 0.52, 7.07 µM, respectively. K_i constants, which are inhibitory-enzyme binding constants, were calculated by using Lineweaver–Burk graphs as 0.16 ± 0.0620, 0.906 ± 0.3029, 0.055 ± 0.0171, 9.363 ± 2.5809, 0.773 ± 0.3204, 7.863 ± 1.9107 µM, respectively. In computer-aided analysis, to gain insights electrochemical properties, synthesized compounds were analysed theoretically by density functional theory. Molecular docking studies and MD simulations were performed to identify possible inhibitor-enzyme binding interactions. According to obtained results, all the compounds formed hydrogen bonds with Asn 112 and Asn 414, and showed π-cation interaction with Phe2 70, gatekeeper residue in target protein. Supporting the nm level inhibition, MD simulations indicate that protein-inhibitor complex maintain the stability and have high number of hydrogen bond formation during the simulation.

Photoluminescence maximum emission signal of colloids based on Bi₂WO₆ suspended in an aqueous solution is blue-shifted as compared to its band gap according to E_{g +} (E_RedOx-E_CB). This process involves the exergonic non-radiative transfer of E_CB electron to E_RedOx and the concomitant radiative emission of a second electron that has gained E_RedOx-E_CB energy presumably by electrons energy levels entanglement induced via simultaneous light excitement of multiple electrons. These results constitute evidence for energy transfer with application in sensing electrolyte-electron-acceptors as reactive oxygen species that may be implemented for example in cancer and aortic dissection detection and treatment.

Graphical abstract

Bi₂WO₆ electrons from water colloidal solution are entangled by light (Plasmon resonance) and excited from the Bi₂WO₆ valence band (VB) to its conduction band (CB). Electron 1 moves up the gradient at the surface and is transferred to the acceptor (E_RedOx) at the electrolyte. The gained energy, E_RedOx—E_Cb, is transferred to electron 2 via their entangled energy levels. Electron 2 then decays to the VB emitting light at the Bi₂WO₆ band gap (E_g) plus the energy gained. Sensing of the E_RedOx and [RedOx] is then obtained.

The protection of the environment is considered to be a major concern of industrial units today. Flare gas combustion systems are inappropriate as a disposal solution or safety measure to decrease pressure. The oil, gas, and petrochemical industries are also concerned about reducing greenhouse gas emissions. Flare gases are associated with non-renewable fossil energies, which have also increased due to the ever-increasing need to harvest underground sources of flare gases. Accumulation of these gases is caused by other reasons such as unburned process gas, excess gas, exhaust gas from units during repairs, technical defects, change of feed, shutdown, and start-up, etc. Research is necessary to collect information regarding revisions to the prevention of burning gases. Identifying the location of energy quality losses, both quantitatively and qualitatively, is the first step in optimizing industrial units. The term “exergy quality” is used to express the amount of exergy loss resulting from exergy analysis. It is possible to determine the critical point of energy loss in a unit by measuring the energy loss in each device, which contributes to increased efficiency. The purpose of this study is to use exergy analysis in order to optimize the recovery of flare gas, which is a form of non-renewable energy. To analyze the exergy of all process equipment, high-pressure steam generation, steam turbine, heat and power generation, and combined cycle processes are selected. According to the literature review, the combined cycle provides the highest rate of electricity recovery. In addition, the exergy analyses of the four processes above are compared, and necessary modifications are made to improve them and the results of economic calculation are presented. The results represented that the highest exergy loss of heat exchangers is equal to 25,776 (kj/kgmole), 26,538.5 (kj/kgmole), 25,776 (kj/kgmole), and 625,828.5 (kj/kgmole) in the processes, respectively.

Actinobacteria emerge as significant producers of bioactive compounds. These compounds exhibit diverse beneficial properties, such as antioxidative, anti-inflammatory, anticancer, antimicrobial, and antiviral attributes. Hot springs, with their high temperatures and unique geochemical conditions, serve as fascinating ecosystems harboring diverse microbial life. In these environments, actinomycetes thrive, utilizing the available organic matter and nutrients. The extreme conditions, characterized by high temperatures and pH levels, likely exert selective pressure, favoring the survival of resilient microorganisms like actinomycetes. This study specifically identified Actinomycetales bacterium spp. (Genbank ID: OP863023), isolated from Rajgir hot spring, as a noteworthy producer of a brown pigment at 43 °C. This isolated strain is known to produce various metabolites identified through GC–MS analysis. Following ADME/T screening of all the metabolites, Diethyl Phthalate (DEP) stands out among those produced by the Actinomycetales bacterium species. The isolated strain demonstrated in vitro antibacterial activity, inhibiting Listeria monocytogenes MTCC1143 with a 10-mm zone of inhibition, while the reference Ampicillin disc showed a 15 mm inhibition zone. In the in silico analysis targeting the Internalin A protein of L. monocytogenes, the Actinomycetales-produced compound DEP displayed an inhibition potential of − 5.4 kcal/Mol, while the reference drug Ampicillin exhibited a higher inhibition potential of − 7.4 kcal/Mol. These findings suggest that the isolated actionobacteria holds promise for antibacterial applications, particularly against L. monocytogenes.

Acute lymphoblastic leukaemia (ALL) is one of the most common types of childhood cancer. Treatment of ALL may involve using the enzyme L-asparaginase (ASNase) from Escherichia coli as the first option. However, native E. coli ASNase can induce the production of antibodies, interfering with its pharmacological activity and increasing the risk of allergic reactions. Therefore, monitoring the production of anti-ASNase antibodies in patients is essential for determining treatment efficacy. Hence, a simple, precise, and selective method for the measurement of antibodies is of great interest. In this context, this work reports on an electrochemical biosensor based on carbon-printed electrodes to quantify antibodies in ALL patients under treatment using an ASNase-based protocol. For selective detection of anti-ASNase antibodies, ASNase was immobilized on electrodes using the nanocomposite Fe₃O₄/chitosan. The biosensor showed linearity for the antibody concentrations between 0.1 and 10 µg mL⁻¹, with a limit of detection of 150 ng L⁻¹. In addition, the biosensor was selective and provided reproducible results with a variability of 3.3%. From these results, it was concluded that the biosensor presented here is a promising device for the measurement of anti-ASNase antibodies produced in patients under treatment for ALL.

Graphical abstract

The study presents a breakthrough of a balanced charge separation for heterojunction CuWO₄-TiO₂ cocatalyst to efficiently enhance visible light photocatalytic degradation of ciprofloxacin (CIP). A solvothermal-synthesized nanopyramid-like CuWO₄ semiconductor was assembled before sol–gel treatment with TiO₂ precursors to generate CuWO₄-TiO₂ nanocomposites. The optical, structural, and morphological properties of CuWO₄-TiO₂ were elucidated using UV–Vis DRS, XRD, FTIR, Raman spectroscopy, and TEM/SEM techniques. The UV–Vis DRS spectroscopy of as-synthesized CuWO₄-TiO₂ cocatalyst demonstrated enhanced visible light absorbance. The XRD patterns of CuWO₄-TiO₂ revealed a triclinic phase nanocrystal. The O-Ti–O functionality was confirmed by FTIR spectroscopy. The photoactive bands corresponding to anatase redshift were observed from Raman spectroscopy of CuWO₄-TiO₂ nanocomposite. The PL studies attributed this redshift to the elevated extra energy bands that aid electron/hole pair charge separation in a co-catalyst heterojunction CuWO₄-TiO₂ nanocomposite afforded by embedding CuWO₄-MOF within TiO₂ crystalline. The TEM showed that un-sintered CuWO₄.MOF mimicked a pyramidal shape and converted to nanoflakes upon sintering, while TiO₂ and CuWO₄-TiO₂ retained a tetragonal shape. The photocatalytic activity of CuWO₄-TiO₂ cocatalyst was studied using CIP, as a model pollutant. The innovative design of 5CuWO₄-TiO₂ charge separation nanocomposite completely degraded 10 mg L⁻¹ CIP solution at pH = 6.31 (natural pH) and 9 under 120 min of sunlight irradiation.

The exceptional film-forming ability, biodegradability, biocompatibility, and wide availability of cross-linked gelatin have sparked considerable interest in its utilization for packaging purposes. APTES (3-Aminopropyltriethoxysilane) cross-linker is preferred due to its ability to bind with gelatin involving its silanol groups and for its non-hazardous nature. This study aims to fabricate cross-linked gelatin films specifically tailored for packaging applications. The FTIR spectra of the gelatin films provided evidence of successful cross-linking, as indicated by the presence of Si–O-Si and Si–OH bonds. SEM analysis exhibited structural uniformity with increasing concentrations of the cross-linker, indicating favorable interactions between APTES and gelatin molecules. Furthermore, enhanced thermal stability was observed, as evidenced by TGA results, suggesting the formation of stable cross-links. The introduction of APTES to the gelatin films preserved their transparency, reduced solubility (from 84 to 58%), lowered water permeability, and increased tensile strength up to 7.3 MPa with the increase in film thickness from 0.129 mm to 0.150 mm. Moreover, the films exhibited decreased transmission of UV light (reduced from 4.8 to 1.4% by adding APTES in the 280 nm wavelength), indicating potential applications in UV protection. Finally, the cross-linked gelatin films modified with APTES demonstrated favorable characteristics for packaging applications.

Hydrogen peroxide (H₂O₂) is an environmentally friendly oxidant, producing only water as a by-product upon decomposition. Given the energy-intensive nature of the conventional anthraquinone process for commercial H₂O₂ production, photocatalytic production of H₂O₂ using graphitic carbon nitride (g-C₃N₄) emerges as a viable alternative. Among the other alternatives for improving the efficiency of g-C₃N₄, potassium ion doping in g-C₃N₄ is one of the efficient methods that can further increases the yield of H₂O₂ production, as the K⁺ doping enhances the photogenerated charge carriers’ separation, intensity and range of visible light absorption, etc. However, traditional methods of catalyst dispersion are inefficient due to the challenges of retrieving the catalyst. Immobilization, while addressing the retrieval issues, adversely affects mass transfer and lowers photocatalyst efficiency. Hence, in this study, we explore an innovative approach to catalyst recycling by forming the catalyst into pellets that avoid immobilization, centrifugation, or any other tedious energy intensive separation process. Pellets of undoped g-C₃N₄ and 10 wt% K-doped g-C₃N₄ are tested for the photocatalytic production of H₂O₂ under direct sunlight and recycled for three times. These materials, i.e., undoped g-C₃N₄ and 10 wt% K-doped g-C₃N₄ pellets are able to produce ~ 407 µM g⁻¹ h⁻¹ and ~ 853 µM g⁻¹ h⁻¹ of H₂O₂, respectively, after three recycles. Such a novel approach of recycling the catalysts in the form of pellets can be extended for the large-scale production of H₂O₂ by loading the pellets to fixed bed column and operating it in continuous flow manner.