Journal Articles - Engineering - 2023
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PublicationThe theoretical prediction of the structural characteristics and SO2 adsorption-sensing properties of pristine HfS2 and TM-doped HfS2 monolayers (TM = Ni, Pd, or Pt)( 2023)(Left panel) A schematic of SO2 gas sensor devices with two Au electrodes and a central region based on TM doped HfS2 monolayers (TM = Ni, Pd or Pt). (Right panel) I–V relationship of the Pt-doped HfS2 monolayer-based sensor.
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PublicationInsights from Experiment and Theory on Peculiarities of the Electronic Structure and Optical Properties of the Tl2HgGeSe4 Crystal( 2023)"Tl2HgGeSe4 crystal was successfully, for the first time, synthesized by the Bridgman−Stockbarger technology, and its electronic structure and peculiarities of optical constants were investigated using both experimental and theoretical techniques. The present X-ray photoelectron spectroscopy measurements show that the Tl2HgGeSe4 crystal reveals small moisture sensitivity at ambient conditions and that the essential covalent constituent of the chemical bonding characterizes it. The latter suggestion was supported theoretically by ab initio calculations. The present experiments feature that the Tl2HgGeSe4 crystal is a high-resistance semiconductor with a specific electrical conductivity of σ ∼ 10−8 Ω−1 cm−1 (at 300 K). The crystal is characterized by p-type electroconductivity with an indirect energy band gap of 1.28 eV at room temperature. It was established that a good agreement with the experiments could be obtained when performing first-principles calculations using the modified Becke−Johnson functional as refined by Tran−Blaha with additional involvement in the calculating procedure of the Hubbard amendment parameter U and the impact of spin−orbit coupling (TB-mBJ + U + SO model). Under such a theoretical model, we have determined that the energy band gap of the Tl2HgGeSe4 crystal is equal to 1.114 eV, and this band gap is indirect in nature. The optical constants of Tl2HgGeSe4 are calculated based on the TB-mBJ + U + SO model"
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PublicationStructural Characterization and Cytotoxic Activity Evaluation of Ulvan Polysaccharides Extracted from the Green Algae Ulva papenfussii( 2023)Ulvan, a sulfated heteropolysaccharide with structural and functional properties of interest for various uses, was extracted from the green seaweed Ulva papenfussii. U. papenfussii is an unexplored Ulva species found in the South China Sea along the central coast of Vietnam. Based on dry weight, the ulvan yield was ~15% (w/w) and the ulvan had a sulfate content of 13.4 wt%. The compositional constitution encompassed L-Rhamnose (Rhap), D-Xylose (Xylp), D-Glucuronic acid (GlcAp), L-Iduronic acid (IdoAp), D-Galactose (Galp), and D-Glucose (Glcp) with a molar ratio of 1:0.19:0.35:0.52:0.05:0.11, respectively. The structure of ulvan was determined using High-Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FT-IR), and Nuclear Magnetic Resonance spectroscopy (NMR) methods. The results showed that the extracted ulvan comprised a mixture of two different structural forms, namely (“A3s”) with the repeating disaccharide [→4)-β-D-GlcAp-(1→4)-α-L-Rhap 3S-(1→]n, and (“B3s”) with the repeating disaccharide [→4)-α-L-IdoAp-(1→4)-α-L-Rhap 3S(1→]n. The relative abundance of A3s, and B3s was 1:1.5, respectively. The potential anticarcinogenic attributes of ulvan were evaluated against a trilogy of human cancer cell lineages. Concomitantly, Quantitative Structure–Activity Relationship (QSAR) modeling was also conducted to predict potential adverse reactions stemming from pharmacological interactions. The ulvan showed significant antitumor growth activity against hepatocellular carcinoma (IC50 ≈ 90 µg/mL), human breast cancer cells (IC50 ≈ 85 µg/mL), and cervical cancer cells (IC50 ≈ 67 µg/mL). The QSAR models demonstrated acceptable predictive power, and seven toxicity indications confirmed the safety of ulvan, warranting its candidacy for further in vivo testing and applications as a biologically active pharmaceutical source for human disease treatment.
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PublicationPalladium nanoparticle formation on boron nitride nanotubes and their photocatalytic performance with visible light( 2023)"Development of efficient but long-term stable photocatalysts for removal of organic pollutants from water sources is still a huge challenge up to date. In this study, palladium nanoparticles (Pd NPs) were dispersed on the surface of boron nitride nanotube (BNNT), a series of Pd@BNNT hybrid was synthesized using a one-step and cost-effective ultrasonication method, and the photocatalytic performance were investigated. By increasing the ultrasonication time, productivity of the Pd NPs on BNNT was increased and also obtained the uniform nanostructure, thereby enhancing the specific surface area, which is the promising attribute for the efficient removal of organic pollutants. In this regard, the Pd@BNNT3 hybrid shows higher photocatalytic performance with respect to other catalysts against the crystal violet and levofloxacin, 97.6%/50 min, and 97.7%/40 min respectively. Further, a reusability test was conducted for the Pd@BNNT3 hybrid by using the CV over seven consecutive cycles. Approximately, 24.7% photocatalytic efficiency was lost in the final catalytic activity owing to its particle loss (7.2%). Significantly, the structure of the Pd@BNNT3 catalyst did not change even after measuring the reusability seven times, suggesting that the catalyst has a stable morphology. The enhanced photocatalytic performance is attributed to the larger specific surface area (128 m2/g) of Pd@BNNT3 hybrid, which enhance the production of the visible light induced radical oxygen species. As a summary, the efficient photocatalyst developed in this study can eliminating the organic contaminants from the wastewater source and is a highly promising solution for tackling wastewater treatment challenges in the near future."
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PublicationHigh-efficient mineralization performance of photocatalysis activity towards organic pollutants over ruthenium nanoparticles stabilized by metal organic framework( 2023)"Fabrication of cost-effective and an efficient catalyst is a greatly crucial to satisfy the requirements of removal of organic pollutants from the wastewater to ensure the green healthy environment yet remains vast challenge. In this regard, simple strategy has been adopted to develop the hybrid structure by employing the ruthenium (Ru) nanoparticles anchored on the metal-organic-framework (Ru@ZIF-8 and Ru@ZIF-67) interface and its overall photocatalytic performance was explored. Experimental results demonstrate that Ru@ZIF-8 hybrid exhibited a higher photocatalytic activity than that of the Ru@ZIF-67, ZIF-8 and ZIF-67 and the degradation efficiency of the crystal violet (CV; 96 %) and rhodamine B (RhB; 97.9) could attain under visible irradiations for about 80 min. In particular, the effects of CV dosage concentrations and various pH effects with the Ru@ZIF-8 hybrid were explored in detail. Moreover, the optimized Ru@ZIF-8 hybrid did not reveal the considerable loss of the photocatalytic activity after six cycles, revealing its long-term reusability and stability. The photocatalytic mechanism was conducted through trapping-species-experiment, confirming that superoxide (•O-2) and electron (e-) contributed significant role in the degradation of the CV with Ru@ZIF-8 hybrid. Thus, the current study offers a new-strategy to design Ru@ZIF-8 as photocatalyst with higher photocatalytic performance for wastewater treatment."