Free Energy Values Research Articles

MW Assisted Synthesis of New 4,6-diaryl-3,4-Didhydropyrimidines-2(1H)-thione Derivatives: Tyrosinase Inhibition, Antioxidant, and Molecular Docking Studies

A number of new methoxy-substituted 4,6-diaryl-3,4-dihydropyrimidine-2(1H)-thiones (DH-Pyr-S, 17-28) were designed and synthesized by the reaction of methoxy-substituted chalcones (1–14) with thiourea using solid-phase microwave method (MW) in view of the structural requirements as suggested in the pharmacophore model for tyrosinase inhibition (TI). Synthesized compounds were assessed for their in vitro TI potential and compounds 16, 17, and 21 exhibited notable tyrosinase inhibitory properties at the concentrations of 31.86 ± 2.45 µM, 44.58 ± 0.46 µM, and 48.47 ± 0.66 µM, respectively. Compounds (16, 17, and 21) were exhibited experimentally more potent TI than the standard used in terms of the IC50 value (Kojic acid, 55.38 ± 2.30 µM; p<0.0001). Additionally, DPPH activity of 15-28 were evaluated and compound 17 showed the moderate DPPH activity (45.64 ± 0.34%). Binding affinities of synthesized molecules to the tyrosinase catalytic core were further investigated through in silico molecular docking studies using AutoDock Vina (version 1.2.5), discovery studio accelyrs (BIOVIA, Dassault Systèmes) and predicting small-molecule pharmacokinetic properties using graph-based signatures (pkCSM) programs were used for ADMET calculations. Among synthesized compounds 15, 21, and 24 revealed high binding affinity to tyrosinase active site with lowest binding free energy (ΔG) values of -7.9 kcal/mol, thereby outperformed kojic acid affinity. In conclusion most modeling results were in agreement with their experimental data, suggesting the TI potential of lead compounds.

Nanocages and nanotubes as catalysts for ORR and OER processes

The capacities, abilities and potential of Ni–C36, Ni–Al18P18, Co–C54, Co–Ge54, Co-CNT(7, 0), Co-GeNT(7, 0), Ni-CNT(10, 0) and Ni-AlPNT(10, 0) to use as catalysts of OER and ORR are examined by theoretical models. The adsorption energy, free Gibbs adsorption energy, overpotential and Gibbs free energy values of ORR and OER on used catalysts are compared with other metal catalysts. The Ni and Co atoms which are doped on nanotubes and nanocages are catalytic positions to adsorb ORR and OER species the and to process the reaction steps of OER and ORR. The Co-GeNT(7, 0) and Ni-AlPNT(10, 0) have lower overpotential than Ni–C36, Ni–Al18P18, Co–C54 and Co–Ge54. Finally, the Co-GeNT(7, 0) and Ni-AlPNT(10, 0) are suggested as catalysts with acceptable stability, high capacity to adsorb the species, lower over-potential and high performances by theoretical models.

Neurotransmitter amino acid adsorption on metal doped boron nitride nanosheets as biosensor: DFT study on neural disease prediagnosis system

In this study, pristine and iron (Fe), copper (Cu) and platinum (Pt) metal doped boron nitride nanosheet (BNNS) structures possibility of biosensor, adsorbent and neural disease prediagnosis system for gama amino butyric acid (GABA) and Glutamate (Glu) molecules were investigated by Density Functional Theory (DFT). Metal atoms were doped to replace both boron (B) and nitrogen (N) atoms of BNNS. All the adsorption energies on the structure were calculated as negative values for all structures after the GABA and Glu adsorption. The lowest adsorption energy and enthalpy values reached to − 42.1 kcal/mol and − 42.7 kcal/mol, respectively. According to Gibbs free energy (∆G) values of adsorption, most of the adsorption reactions can occur spontaneously. The charge transfer during adsorption happened from GABA and Glu molecules to BNNS structures. Based on the results, Fe-doped BNNS and Cu-doped BNNS could be utilized as electronic and work function type biosensors for GABA molecule and Glu molecule respectively. This study may lead to future biosensor studies, adsorption studies of neurotransmitter amino acids other than GABA and Glu, and BN nanostructure studies modified with different metal doping.

Atomic Diffusion Bonding in Air Using Oxide Films

Atomic diffusion bonding (ADB) of wafers is a promising process to achieve room-temperature wafer bonding [1]. For ADB processing, thin films are fabricated on two flat wafer surfaces using sputter deposition, with subsequent bonding of the two films on the wafers in vacuum. In addition to thin metal films [1], both oxide [2] and nitride [3] thin films are useful for bonding.For this study, after demonstrating ADB “in air” using oxide films, we compared the resultant bonding performance to that obtained using ADB “in vacuum” with the oxide films. Table 1 presents the surface free energy values at the bonded interface γ for quartz glass wafers bonded using 5-nm-thick Y2O3 film on each side. Using ADB in vacuum, great bonding strength was achieved for as-bonded wafers: the blade could not be inserted between the wafers. Using ADB in air, γ for as-bonded wafers was small, only 0.25 J/m2, but low-temperature annealing at 150 °C enhanced γ to 1.6 J/m2. At 200 °C, γ becomes greater than 2 J/m2. The annealing was conducted in air using a hot plate. Figure 2 portrays STEM cross-section images of Y2O3(5 nm)/Y2O3(5 nm) films (A) bonded in vacuum (as-bonded) and (B) bonded in air (annealed at 150 °C). The bonded interface is not visible in image (A). However, a slightly low-density bonded interface is partially visible in image (B). The difference of the bonded interface structure is consistent with that of γ presented in Table 1.Various oxide films such as TiO2, ITO, SiO2, and WO3 are useful for ADB in air, as is true also for ADB in vacuum, although post-bonded annealing at a low temperature of 150 °C is necessary for ADB in air to achieve γ greater than 1 J/m2. The bonding process of ADB in air is more convenient to execute than that in vacuum. Moreover, any mirror-polished wafer can be bonded using ADB in air, as is true also using ADB in vacuum. It is likely that H2O gas in air can adsorb on the fresh surface of oxide films efficiently and that well-hydrophilic films surfaces can be obtained easily when the deposited oxide films are removed from the vacuum chambers; in fact, low-temperature annealing at 150 °C enhanced γ remarkably. ADB in air using oxide films is useful for some applications if post-bonded annealing at low temperatures is acceptable for bonding processes. T. Shimatsu and M. Uomoto, ECS Trans., 33 (4), 61 (2010).T. Shimatsu, H. Yoshida, M. Uomoto, T. Saito, T. Moriwaki, N. Kato, Y. Miyamoto, and K. Miyamoto, Proceedings of Seventh LTB-3D 2021. p.51 (2021).M. Uomoto, H. Yoshida, T. Shimatsu, T. Saito, T. Moriwaki, N. Kato, Y. Miyamoto, and K. Miyamoto, Proceedings of Seventh LTB-3D 2021. p.45 (2021). Figure 1

Adhesion of methylene blue and malachite green to the surface of copolymer synthesized by grafting itaconic acid onto cellulose backbone – experimental and computational studies

This report describes the graft copolymerization of itaconic acid onto cellulose isolated from plantain trunk, using ammonium persulfate as initiator. Optimum grafting condition was established at 0.025 mol/L initiator concentration, 60 °C, 60 min grafting time and 3 g monomer mass. Characterization of the bio-materials indicated the success of the cellulose isolation and the grafting processes. At optimum grafting condition, about 34.0% grafting yield was obtained. With 25 mg of the co-polymer (PTC-g-IA), MB and MG uptake were 72.5 and 56.9 mg/g, respectively. These values represent about 2-fold sorption enhancement when compared with ungranted cellulose (PTC). The sorption process was influenced by solution pH, contact time, dye concentration and temperature. Modeling of the adsorption process indicated that the Pseudo-second-order kinetic model with R2 of unity and the Langmuir isothermal model (R2: 0.9622 (MB) and 0.9880 (MG)) best described the sorption process. Thermodynamic study described a feasible, spontaneous and exothermic process. Free energy value of 7.07 kJ/mol, and ΔH° values of < 20 kJ / mol , suggested a physisorption process. This was corroborated by the computational study which indicated non-covalent interactions between atoms in the dyes and the adsorbents. These interactions were stronger with the co-polymer. The interaction energies calculated for the dye-adsorbent interaction (-38.215, −52.868, −47.299 and −57.848 kJ/mol for PTC-MB, PTC-MG, PTC-g-IA-MB and PTC-g-IA-MG, respectively) show stronger interactions between PTC-g-IA and the dye molecules compared to pure cellulose in line with experimental observations. In overall, this study portrays the cellulose-based co-polymer as having the potential of easily removing MB and MG from wastewater.

Stabilization of whey lactoperoxidase using betaine: Spectroscopic and computational approaches

Lactoperoxidase (LPO) is a peroxidase with antibacterial properties. In the present study, lactoperoxidase was isolated and stabilized using betaine. Betaine enhanced optimal pH, enzyme native activity, and enzyme residual activity. Betaine reduced LPO fluorescence using a static quenching mechanism. The results showed that hydrogen bonding and van der Waals interactions were responsible for ligand-LPO binding. The negative values of Gibes free energy indicated that the binding of betaine to the LPO was spontaneous. The circular dichroism studies showed that the secondary and tertiary structures of the enzyme were altered in the presence of betaine. The results of thermal stability studies presented that betaine increased the enzyme Tm. Furthermore, the docking and MD investigations demonstrated that betaine might spontaneously attach to the LPO with hydrogen bonding and van der Waals interactions. Finally, betaine might be employed as an additive to stabilize lactoperoxidase for usage in the food and pharmaceutical industries.

DFT-ONIOM study of ammonia activation by MM'APO-5 (M,M' = Ti, Zr, Co) bimetallic molecular sieves. The influence of the neighboring metal from a theoretical point of view

ONIOM-DFT calculations have been carried out in order to determine how the neighboring metal influences the activation free energies (ΔG≠) and the mechanisms of NH3 activation in a series of mono and disubstituted aluminophosphates MM’APO-5, (M, M’ = Co, Ti Zr). The results revealed that metal clustering is thermodynamically favorable (ΔG < 0) for all MAPO-5s and MM’APO-5s studied here. The aluminophosphates TiAPO-5 and ZrAPO-5 are unable to activate NH3 due to their inability to stabilize the key intermediate MNH2. The calculated activation free energy values (ΔG≠) suggest that CoZrAPO-5 is better suited for NH3 activation, as its values are lower than those of CoTiAPO-5 in the mechanism studied.

Tetra-Coordinated W2 S3 for Efficient Dual-pH Hydrogen Production.

Two-dimensional (2D) transition-metal dichalcogenides (TMDs) have emerged as promising catalysts for the hydrogen evolution reaction (HER) that play a crucial role in renewable energy technologies. Breaking the inherent structural paradigm limitations of 2D TMDs is the key to exploring their fascinating physical and chemical properties, which is expected to develop a revolutionary HER catalyst. Herein, we unambiguously present metallic W2 S3 instead of energetically favorable WS2 via a unique stoichiometric growth strategy. Benefiting from the excellent conductivity and hydrophilicity of the tetra-coordinated structure, as well as an appropriate Gibbs free energy value and an enough low energy barrier for water dissociation, the W2 S3 as catalyst achieves Pt-like HER activity and high long-term stability in both acidic and alkaline electrolytes. For application in proton exchange membrane (PEM) and anion exchange membrane (AEM) electrolysers, W2 S3 as the cathode catalyst yields excellent bifunctionality index (ɳ =1.73 V, ɳ =1.77 V) and long-term stability (471 h@PEM with a decay rate of 85.7 μV h-1 , 360 h@AEM with a decay rate of 27.1 μV h-1 ). Our work provides significant insight into the tetra-coordinated W2 S3 and facilitates the development of advanced electrocatalysts for sustainable hydrogen production.

Tetra‐Coordinated W2S3 for Efficient Dual‐pH Hydrogen Production

AbstractTwo‐dimensional (2D) transition‐metal dichalcogenides (TMDs) have emerged as promising catalysts for the hydrogen evolution reaction (HER) that play a crucial role in renewable energy technologies. Breaking the inherent structural paradigm limitations of 2D TMDs is the key to exploring their fascinating physical and chemical properties, which is expected to develop a revolutionary HER catalyst. Herein, we unambiguously present metallic W2S3 instead of energetically favorable WS2 via a unique stoichiometric growth strategy. Benefiting from the excellent conductivity and hydrophilicity of the tetra‐coordinated structure, as well as an appropriate Gibbs free energy value and an enough low energy barrier for water dissociation, the W2S3 as catalyst achieves Pt‐like HER activity and high long‐term stability in both acidic and alkaline electrolytes. For application in proton exchange membrane (PEM) and anion exchange membrane (AEM) electrolysers, W2S3 as the cathode catalyst yields excellent bifunctionality index (ɳ =1.73 V, ɳ =1.77 V) and long‐term stability (471 h@PEM with a decay rate of 85.7 μV h−1, 360 h@AEM with a decay rate of 27.1 μV h−1). Our work provides significant insight into the tetra‐coordinated W2S3 and facilitates the development of advanced electrocatalysts for sustainable hydrogen production.

Superhydrophobic Coatings for Corrosion Protection of Stainless Steel

Corrosion is a persistent challenge in the aviation industry, affecting the safety, performance, and maintenance costs of aircraft. While composite materials have gained widespread use due to their lightweight properties and corrosion resistance, certain critical parts, such as the wing and empennage leading edges and the engine inlet, demand alternative solutions. Aluminum, titanium, and stainless steel emerge as mandatory materials for such components, given their exceptional strength and durability. However, protecting these metallic components from corrosion remains crucial. In this paper, we present a study aimed at evaluating the corrosion resistance of stainless steel, employed as an erosion shielding panel for a composite vehicle’s wing, layered with a superhydrophobic coating. The samples with and without coating have been characterized by contact angle measurements, microscopy (optical and electronic), and visual inspection after immersion in two solutions, NaCl and NaOH, respectively. The application of the superhydrophobic coating demonstrated a significant reduction in corrosion extent, especially in the demanding NaCl environment. This was evidenced by diminished formation of ripples and surface roughness, decreased iron oxide formation from oxidative processes, and a lower Surface Free Energy value in both liquid environments. Notably, the surface maintained its superhydrophobic properties even following an 8-day immersion in NaCl and NaOH solutions, demonstrating the reliability of the superhydrophobic coating offering as a potential solution to enhance the longevity and reliability of aircraft structures.

IN SILICO STUDY OF THE SYNERGISTIC INTERACTION OF 5-FLUOROURACIL AND CURCUMIN ANALOGUES AS INHIBITORS OF B-CELL LYMPHOMA 2 PROTEIN

Objective: The research objective is to explore the potential for synergistic inhibition of two curcumin analogs combined with 5-fluorouracil (5-FU) against the B-cell lymphoma 2 (BCL-2) protein.&#x0D; Methods: We investigated the synergistic inhibition of two curcumin analogs, namely, (1E,4E)-1,5-bis(4-hydroxyphenyl)penta-1,4-dien-3-one (AC01) and (1E,4E)-1,5-bis(3,4-dihydroxyphenyl)penta-1,4-dien-3-one (AC02), each combined with 5-FU by calculating their binding free energies and binding stability. An in silico investigation of the synergistic interaction of ligand pairs was conducted using the multiple ligand simultaneous docking (MLSD) technique with the AutoDock Vina package. The stability of interactions and binding free energies of each BCL-2 and curcumin analogs were examined by applying molecular dynamics techniques with the Gromacs package and MMPBSA method.&#x0D; Results: All ligand pairs had displayed strong binding affinity, as evidenced by highly negative free energy values, indicating a robust association with BCL-2. Molecular dynamics simulations were conducted over 100 ns, confirming good stability with controlled RMSD changes, suggesting that the ligand pairs had remained securely bound to the BCL-2 binding site. Additionally, RMSF analysis and energy decomposition had revealed that ligand interactions did not influence protein residue fluctuations during the simulation, and the protein-ligand complexes had maintained stability throughout the simulation. Furthermore, binding free energy calculations using the MMPBSA method had consistently shown negative values, signifying stable interactions with BCL-2 for all ligand pairs.&#x0D; Conclusion: In conclusion, our study revealed that AC01 and AC02, when combined with 5-FU, had the ability to intercalate into the P2 and P4 sites of BCL-2. This suggested that AC01 and AC02 held promise for further study as candidates for anticancer drugs, individually or in combination with 5-FU.

An integrated network pharmacology and molecular modelling study of phytoconstituents targeting Alzheimer's disease

The present study involves the use of combined network pharmacology and molecular modelling approach for identifying important phytoconstituents that could modulate the functions of multiple therapeutic targets in Alzheimer’s disease. A list of botanicals reported in the literature for their efficacy in Alzheimer’s disease, the phytochemicals present in the botanicals were identified with the help of network pharmacology approach. The pharmacokinetic properties like blood brain barrier penetration and Lipinski’s rule of five for the selected phytoconstituents were analyzed. The major targets involved in the pathogenesis of Alzheimer’s disease were collected from the DisGeNET database. The selected proteins were subjected to topological analysis using Cytoscape software to identify the important targets in the network. The top 7 phytoconstituents and 5 proteins were subjected to molecular docking, MM-GBSA and molecular dynamics studies. A total of 15 plants and 1443 phytoconstituents were identified through a literature survey and from several databases. The pharmacokinetics study revealed that 7 phytoconstituents - glycyrrhisoflavone, eugenol, ferulic acid, methyl jasmonate, geranyl formate, formononetin, and elemicin- exhibited favourable pharmacokinetic properties. Five targets, HMOX1, CNR1, STAT3, HDAC2, and MAOB were found to be important in the network of 3300 proteins based on degree centrality and betweenness centrality. Among the seven phytoconstituents, glycyrrhisoflavone exhibited good dock scores and free energy value. Based on this, the stability of glycyrrhisoflavone with the five selected targets were analyzed using molecular dynamics study. Glycyrrhisoflavone showed good stability with most of the selected therapeutic targets. The current study reveals that the selected phytoconstituents i.e glycyrrhisoflavone, eugenol, ferulic acid, methyl jasmonate, geranyl formate, formononetin, and elemicin could serve as good lead molecules in treatment and management of Alzheimer’s disease through modulation of multiple targets.

Structural, optoelectronic and thermodynamical insights into 2H-ZrO2: A DFT investigation

The monolayer transition metal dichalcogenides have appeared to be an intriguing area of ongoing research in two-dimensional materials. In this study, we have investigated the structural, lattice dynamic, optoelectronic and thermodynamic properties of 2H-ZrO2 monolayer using first-principle calculations. The negative value of cohesive energy (-0.42 eV) manifests that 2H-ZrO2 is structurally stable and can be fabricated experimentally. The optimized lattice constant is found to be 3.15 Å. Lattice dynamic stability is assessed by the phonon dispersion curves and phonon density of states, which indicating that 2H-ZrO2 monolayer is dynamic stable. In order to analyze the thermal stability of 2H-ZrO2, we have computed thermodynamic properties within the range of 0–1000 K. The negative values of free energy indicate the thermal stability of the monolayer. Various electronic parameters such as density of states, partial density of states and electronic band structure have been obtained. It is found that 2H-ZrO2 is a p-type semiconductor, which possesses an indirect bandgap of 1.58 eV between valence and conduction bands. A number of in-plane and out-of-plane optical spectra have been discussed in detail. This study suggested that monolayer 2H-ZrO2 is a suitable candidate for energy related applications and may aid in the creation of effective optoelectronic devices.

Virtual screening and identification of promising therapeutic compounds against drug-resistant Mycobacterium tuberculosis β-ketoacyl-acyl carrier protein synthase I (KasA)

The emergence of new Mycobacterium tuberculosis (Mtb) strains resistant to the key drugs currently used in the clinic for tuberculosis treatment can substantially reduce the probability of therapy success, causing the relevance and importance of studies on the development of novel potent antibacterial agents targeting different vulnerable spots of Mtb. In this study, 28,860 compounds from the library of bioactive molecules were screened to identify novel potential inhibitors of β-ketoacyl-acyl carrier protein synthase I (KasA), one of the key enzymes involved in the biosynthesis of mycolic acids of the Mtb cell wall. In doing so, we used a structure-based virtual screening approach to drug repurposing that included high-throughput docking of the C171Q KasA enzyme with compounds from the library of bioactive molecules including the FDA-approved drugs and investigational drug candidates, assessment of the binding affinity for the docked ligand/C171Q KasA complexes, and molecular dynamics simulations followed by binding free energy calculations. As a result, post-modeling analysis revealed 6 top-ranking compounds exhibiting a strong attachment to the malonyl binding site of the enzyme, as evidenced by the values of binding free energy which are significantly lower than those predicted for the KasA inhibitor TLM5 used in the calculations as a positive control. In light of the data obtained, the identified compounds are suggested to form a good basis for the development of new antitubercular molecules of clinical significance with activity against the KasA enzyme of Mtb. Communicated by Ramaswamy H. Sarma

The Supersymmetry Genetic Code Table and Quadruplet Symmetries of DNA Molecules Are Unchangeable and Synchronized with Codon-Free Energy Mapping during Evolution.

The Supersymmetry Genetic code (SSyGC) table is based on five physicochemical symmetries: (1) double mirror symmetry on the principle of the horizontal and vertical mirror symmetry axis between all bases (purines [A, G) and pyrimidines (U, C)] and (2) of bases in the form of codons; (3) direct-complement like codon/anticodon symmetry in the sixteen alternating boxes of the genetic code columns; (4) A + T-rich and C + G-rich alternate codons in the same row between both columns of the genetic code; (5) the same position between divided and undivided codon boxes in relation to horizontal mirror symmetry axis. The SSyGC table has a unique physicochemical purine-pyrimidine symmetry net which is as the core symmetry common for all, with more than thirty different nuclear and mitochondrial genetic codes. This net is present in the SSyGC table of all RNA and DNA living species. None of these symmetries are present in the Standard Genetic Code (SGC) table which is constructed on the alphabetic horizontal and vertical U-C-A-G order of bases. Here, we show that the free energy value of each codon incorporated as fundamentally mapping the "energy code" in the SSyGC table is compatible with mirror symmetry. On the other hand, in the SGC table, the same free energy values of codons are dispersed and a mirror symmetry between them is not recognizable. At the same time, the mirror symmetry of the SSyGC table and the DNA quadruplets together with our classification of codons/trinucleotides are perfectly imbedded in the mirror symmetry energy mapping of codons/trinucleotides and point out in favor of maintaining the integrity of the genetic code and DNA genome. We also argue that physicochemical symmetries of the SSyGC table in the manner of the purine-pyrimidine symmetry net, the quadruplet symmetry of DNA molecule, and the free energy of codons have remined unchanged during all of evolution. The unchangeable and universal symmetry properties of the genetic code, DNA molecules, and the energy code are decreasing disorder between codons/trinucleotides and shed a new light on evolution. Diversity in all living species on Earth is broad, but the symmetries of the Supersymmetry Genetic Code as the code of life and the DNA quadruplets related to the "energy code" are unique, unchangeable, and have the power of natural laws.

Biological Activity of Canned Pork Meat Fortified Black Currant Leaf Extract: In Vitro, In Silico, and Molecular Docking Study.

The aim of this study was to assess the antioxidant and inhibiting (ACE-I, DPP IV, and alpha-glucosidase) potential of canned meat featuring reduced sodium nitrate content (50 mg/kg) and fortified with freeze-dried currant leaf extract. Research indicates that employing a lyophilizate dose of 150 mg/kg yields optimal benefits in terms of the antioxidant activity of the meat product. Additionally, three highly promising sequences for canned meat were identified via analysis in the BIOPEP database. These sequences are RPPPPPPPPAD, exhibiting DPP-IV inhibiting activity; ARPPPGPPPLGPPPPGP, demonstrating ACE-I inhibiting activity; and PPGPPPPP, displaying alpha-glucosidase inhibiting activity. Using bioinformatics tools, molecular docking was performed by pairing the selected peptides with protein receptors 2QT9, 1O86, and 5NN8, respectively (PDB ID). The examination of the potential of these selected sequences to manifest specific biological activities toward enzymes was based on the free energy value (∆Gbinding). This knowledge can be harnessed for designing functional foods, thereby contributing to the safeguarding of consumer health.

Synergistic boost of catalytic activity in ZrTe topological catalyst via multiple topologically-electronic states

Topological materials feature highly-active topological surface states and high carrier mobility, making them promising catalysts. While ongoing research centers on topological catalysis, most topological semimetal catalysts tend to showcase either a singular topological electronic state or a lone highly catalytic surface, imposing limitations on overall efficiency. Our study highlights ZrTe as a standout catalyst for hydrogen evolution, boasting multiple topological states that excel across various surfaces. ZrTe exhibits a Weyl nodal ring and a triple degenerate nodal point near the Fermi energy, resulting in topological surface states on multiple surfaces. Notably, the (010) and (001) surfaces exhibit remarkable catalytic performance, with Gibbs free energy (ΔGH*) values surpassing that of the Pt metal. Our work establishes a robust and unequivocal link between catalysis and topological properties on the catalytic surfaces, revealing a linear correlation between ΔGH* and topological surface state density. ZrTe emerges as an exceptional topological catalyst, with both of its topological states significantly contributing to the catalytic performance on distinct surfaces. This pioneering discovery offers a valuable platform for advancing catalyst research in the concept of topological catalysts.

Glutaraldehyde Crosslinked Alginate-Chitosan Nanoparticles as Paracetamol Adsorbent

Paracetamol contained in wastewater can cause adverse effects on animal ecosystems, such as fish living in waters and cause harmful effects on humans. Adsorption techniques are used to remove these pharmaceutical compounds. Alginate-chitosan nanoparticles are non-toxic and effectively used as adsorbents to remove pharmaceutical compounds in wastewater. Research on glutaraldehyde crosslinked alginate-chitosan nanoparticles as paracetamol adsorbent has been carried out. This research used the ionic gelation method. Nanoparticles were characterized using transmission electron microscopy (TEM), scanning electron microscope (SEM-EDX) and Fourier transform infra-red spectrophotometer (FTIR). Furthermore, the nanoparticles were used for paracetamol adsorption. The results showed that the form nanoparticles are coarse solid powder and brownish yellow. The TEM image shows an average nanoparticle size of 8.22 nm. Glutaraldehyde crosslinked alginate-chitosan nanoparticles adsorbed paracetamol with adsorption kinetics followed a pseudo-second-order or Ho-McKay model, the adsorption rate constant of 0.0324 g mg−1 min−1. The isotherm study of paracetamol adsorption by glutaraldehyde cross-linked alginate-chitosan nanoparticles followed the isotherm Dubinin-Radushkevich isotherm model with a free energy value of 707.1068 kJ mol−1, and this value indicates the adsorption process by chemically or chemisorption.

Natural bamboo powder and coffee ground as low-cost green adsorbents for the removal of rhodamine B and their recycling performance

Bamboo and coffee, which are abundant and inexpensive, have been used as green adsorbents for the adsorption of industrial dye rhodamine B (RB). Bamboo and coffee are natural sources of cellulose, hemicellulose, and lignin, making them promising green materials for industrial dye removal. The effects of various adsorption conditions, such as contact time, temperature, dose of bamboo powder (BP), coffee ground (CG), initial concentration of RB, and pH values of RB solution, were measured. Consequently, the kinetics of RB adsorption onto bamboo and coffee was in accordance with the pseudo-second-order model, with an activation energy of 29.51 kJ mol−1 for bamboo and 27.46 kJ mol−1 for coffee. The Langmuir model is well fitted to the whole adsorption period at different temperatures, in which the increase in the tested temperature has improved the adsorption capacity (i.e., BP: 6.76 mg g−1/30 °C, 6.96 mg g−1/40 °C, 7.64 mg g−1/50 °C and CG: 6.53 mg g−1/30 °C, 6.80 mg g−1/40 °C, 7.51 mg g−1/50 °C). Moreover, the spontaneous nature of the adsorption was based on the negative Gibbs free energy values obtained (i.e., from − 11.09 to − 14.30 kJ mol−1 [BP] and from − 10.34 to − 13.07 kJ mol−1 [CG]). These revealed that RB adsorption occurred at physical and chemical adsorption states. In addition, the recycling capability of adsorbents was determined in five cycles. Therefore, these materials are promising candidates for low-cost adsorbents.

Thermodynamic, structural and surface properties of rare earth metallic alloys: Au-La liquid system

A complete information related to the mixing behaviours of Au alloyed with rare earth metals or lanthanides is very scarce. Therefore, an attempt has been made in this work to compute and study the temperature and concentration dependent thermodynamic, structural and surface properties of Au-La liquid alloy using different theoretical approaches. The thermodynamic properties, such as excess Gibbs free energy of mixing, enthalpy of mixing, excess entropy of mixing and activity of the system were computed using available coefficients of interaction energy parameters in the framework of Redlich-Kister polynomial. Taking these as reference values, model parameters for quasi-lattice model were optimised at 1473 K. The model parameters were then determined at higher temperatures assuming them to be linear temperature-dependent. The thermodynamic and structural properties were then computed in the temperature range 1473 K-1773 K. The surface properties of the system were computed using Bulter’s model using determined values of partial excess Gibbs free energy of its components. Present investigations revealed that the compound forming tendency of the system gradually decreased with increase in temperature of the system.