Exothermic Research Articles

Dephosphorisation behaviour of blast oxygen furnace (BOF) slag due to carbothermal reduction

ABSTRACT The thermodynamic analysis of converter slag by carbothermal reduction was carried out. The laboratory tests of converter slag by carbothermal reduction dephosphorisation were carried out in molybdenum disilicide high-temperature resistance furnace and 500 kg top bottom combined blowing multi-functional test furnace respectively. The results show that the reaction temperature and kinetic conditions have a great influence on the dephosphorisation rate. In the top and bottom combined blowing multi-functional test furnace, coke powder is used as both reducing agent and heating agent. The exothermic reaction between coke powder and oxygen can ensure that the dephosphorisation reaction can be carried out at a higher temperature. At the same time, the good stirring of topblowing oxygen on the slag layer is conducive to further improve the dephosphorisation reaction speed.

Convection flow of NE-phase change material-water mixture in evacuated tube solar collector manifold: Numerical analysis of MHD double-diffusive convection and exothermic reaction

This study investigates the convection flow of nano-encapsulated phase change material (NEPCM)-water mixture in an evacuated tube solar collector manifold, focusing on the effects of magnetohydrodynamic (MHD) double-diffusive convection and exothermic reaction. Computational fluid dynamics simulations using the Galerkin finite element method were employed to analyze temperature and concentration distributions, fluid flow, melting zone of PCM nanocapsules, Nusselt number, Sherwood number, entropy generation, and thermal performance. The numerical analysis considers a range of dimensionless parameters, including Rayleigh number (Ra=103−105), Lewis number (Le=0.1−10), buoyancy ratio (Nz=1−5), nanoparticle concentration (ϕ=0.01−0.035), fusion temperature (ϴf=0.1−0.9), Stefan number (Ste=0.1−0.9), Hartmann number (Ha=0−50), magnetic field inclination angle (γ=0°−90°), and Frank-Kamenetskii number (FK=0−2.5). Results show that increasing Ra enhances the average Nusselt number (Nuav) by up to 156.1 % and the average Sherwood number (Shav) by up to 104.5 %, while increasing the total entropy generation by up to 13,155 %. Increasing FK reduces Nuav by up to 42.2 % but increases Shav by up to 13.1 %. The Lewis number and buoyancy ratio significantly influence the hydrothermal performance, with Nuav exhibiting non-monotonic behavior and Shav increasing by up to 240.9 % as Le increases. The nanoparticle concentration enhances Nuav by up to 49.7 %. Interestingly, the magnetic field effects are less pronounced than in previous studies, with Ha having a minor impact on Nuav and Shav. These findings have significant implications for the design and optimization of evacuated tube solar collectors and other thermal energy storage systems, potentially leading to improved efficiency and performance in real-world applications.

Investigation on mechanism of mechanical activation and chemical reactions in CMP of diamond assisted by hydroxyl free radicals

Chemical mechanical polishing (CMP) is a crucial manufacturing process for diamond substrate applications. However, due to the extremely high hardness and chemical stability of diamond, its CMP efficiency is extremely low. This study aims to achieve microscopic simulation of atomic oxidation removal at the three-phase interface between diamond abrasive particle, diamond substrate, and hydroxyl free radicals (∙OH) aqueous solution. The mechanical activation behavior, microscopic mechanism, and feasibility of elementary reactions in the ∙OH aqueous solution environment was studied using various perspectives of radial distribution function, central atomic coordination state, atomic bonding and removal forms, energy, electron orbitals, and density functional theory (DFT). The simulation results indicate that during the process of diamond atomic oxidation removal, the atomic density at the first adjacent position centered on one atom decreases, and the stable covalent bond structure is disrupted, resulting in an amorphous phase transition. The chemical adsorption reaction generates C-O and C–H bonds. The C atoms mainly separate from the diamond substrate by the forming products such as carbon monoxide (CO), carbon dioxide (CO2), and carbon chains. The mechanical activation behavior indirectly reduces the activation energy of chemical reactions, while increasing the absolute value of adsorption energy and improving the ability of chemical adsorption solution atoms H and O, as well as ∙OH groups. Based on DFT, it has been verified that the intrusion process of ∙OH groups in the elementary reactions involving the typical product C*O2 is an exothermic reaction that can occur spontaneously, and the energy barrier needs to be overcome by the mechanical action of abrasive particles. At the same time, the energetics of the oxidation of diamond C atoms to generate C*O2 have successfully confirmed that the combined action of ∙OH and diamond abrasive particles is expected to achieve efficient oxidation removal and finishing polishing of diamond atoms.

Increasing LNAPL density and viscosity are indicators of Natural Source Zone Depletion

Natural source zone depletion (NSZD) acts to reduce the mass and/or toxicity of light non-aqueous phase liquids (LNAPL) in the shallow subsurface. Several indirect measurement techniques are commonly used to estimate LNAPL mass depletion based on CO 2 generation by hydrocarbon mineralisation, heat production by exothermic biodegradation processes, and sub-surface gas concentration gradients. This paper presents data on LNAPL density and viscosity and shows changes that result from NSZD processes. Increasing trends in LNAPL density and viscosity were observed that provided a qualitative line-of-evidence for NSZD. When LNAPL density and viscosity were combined with contemporaneous LNAPL chemistry analysis it was possible to correlate changes in the physical properties to depletion of alkanes from the LNAPL in a manner that would inform a quantitative NSZD assessment. LNAPL density and viscosity measurements are relatively cheap and reproducible, and increasing trends in LNAPL density and viscosity provide additional lines-of-evidence for NSZD.

Sustainable fluoride removal with scrap aluminum: Co-producing cryolite and hydrogen

This study presents a novel continuous process for fluoride removal and re- source recovery as cryolite, using a scrap aluminum-packed column. Efficient aluminum dissolution in hydrofluoric acid (HF) generates hydrogen gas and provides cost-saving alkalinity. The process achieves high efficiency (Al/F molar ratio of 2/6) within short Empty Bed Contact Times (15 min) and at low HF concentrations (500 mg/L). Solution pH plays a crucial role, with Al/F ratios above 1 achievable at pH below 4. The exothermic reaction requires temperature control, with a strong correlation (R²=0.99) between HF concentration and heat generation. Hydrogen production matches theoretical predictions. Cryolite synthesis was confirmed at optimized pH (5–5.5) with a 1:1 bypass ratio, achieving 98 % fluoride removal. XRD and SEM- EDS analyses verified cryolite formation. This approach offers a promising solution for industrial fluoride management, resource recovery, and clean hydrogen production.

The Curious Case of Pu+: Insight on 5f Orbital Activity from Inductively Coupled Plasma Tandem Mass Spectrometry (ICP-MS/MS) Reactions.

A comprehensive understanding of when and how 5f orbitals participate in complex chemical bonding is important for a variety of applications. The actinides are unique in that they possess 5f orbitals and can access high oxidation states, which make them attractive for use in catalysis. Fundamental studies of actinide-ligand interactions offer a mechanism to examine the activation of the 5f orbitals so that the selectivity of 5f orbitals can be assessed. A previous study examined the reaction of Pu+ + CO2 and determined that the reaction efficiency is restricted by a barrier, namely, promotion from the Pu+ ground-state configuration, 5f67s, to a reactive-state configuration, 5f56d2. The present study illustrates the benefit of activation of Pu's 5f orbitals when studying the reaction of Pu+ + NO. In this reaction, PuO+ forms in an exothermic, barrierless process. The 5f orbitals can and do participate in forming a linear intermediate, [N-Pu-O]+, and this drives the exothermic reaction. Understanding the conditions under which 5f orbitals are active in chemical bonding is the key to exploiting the actinides' selective catalytic capabilities.

Flexible MOF@fabrics composites: The in-situ growth of metal-organic frameworks on cotton and selectively adsorption of gold(III) from aqueous solution

Metal-organic frameworks (MOFs) show great potential applications in dealing with heavy metal pollution due to their unique large specific surface area, tunable pore size, and diverse active groups. However, the powder form of MOFs has suffered from the disadvantages of difficult recycling and secondary contamination after adsorption of heavy metals, which seriously limits their practical application. Therefore, in this work, we prepared a series of bifunctional zirconium-based MOFs cotton fabric composites (MCFC) via in situ growth of MOFs on carboxylated cotton fabric, exhibiting large specific surface area, adjustable pore size, and effective adsorption ability. The prepared CF-UiO-66-(OH)2-FA shows an excellent adsorption efficiency of Au(III) more than 99.990 %, and the saturated adsorption amount is up to 190.98 mg·g−1 at 25 °C. Meanwhile, the kinetic experiment analysis demonstrated that the Au(III) adsorption behavior of MCFC follows pseudo-second-order (PSO) kinetic model. More importantly, it also exhibits great selectivity in adsorbing Au(III) from the mixture of multiple metal ions coexisted solution. The results of adsorption thermodynamics and adsorption isotherms indicate that adsorption is monolayer and a spontaneous, exothermic process. And the ideal adsorption and separation process could be finished by quickly filtrating with a single or multi-layer MCFC. Excellent adsorption performance even after four cycles of adsorption. Therefore, the fabricated MCFC shows great processability, flexibility, collectability and reusability in adsorbing and recycling precious metal ion from wastewater.

Investigations on the complexation and binding mechanism of bovine serum albumin with Ag-doped TiO2 nanoparticles.

It is essential to study the interactions between nanoparticles and proteins to better understand the biological interactions of nanoparticles. In this study, we studied the protein adsorption mode on the surface of Ag-doped TiO2 nanoparticles (NPs) using a model protein, bovine serum albumin (BSA). The mechanism of binding BSA to the Ag-doped TiO2 NPs was studied by applying fluorescence quenching, absorbance measurements, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy techniques. The strong binding between BSA and Ag-doped TiO2 NPs was confirmed by a high value of binding constant (K = 2.65 × 105 L mol-1). We also studied the thermal stability of BSA in the presence of the Ag-doped TiO2 NPs. Thermodynamic parameters indicated that the adsorption of BSA on the Ag-doped TiO2 NPs was a spontaneous, natural and exothermic process. The effect of Ag-doped TiO2 NPs on the transportation function of BSA was also studied using a fluorescence spectroscopic technique. Fluorescence spectroscopic data suggested the existence of a strong interaction between BSA and the surface of the Ag-doped TiO2 NPs, which indicated that the binding affinities of some selected amino acids in BSA changed. This, in turn, clearly confirms that the Ag-doped TiO2 NPs affect the transportation capability of BSA in blood.

Reactivity tuning of metastable intermolecular composite Al/PFOA by polydopamine interfacial control

Controlling the high reactivity resulting from interfacial contact between nanoscale components poses a significant challenge. This study introduces an approach utilizing an aluminum (Al) surface-modified material to regulate the interaction between Al and perfluorooctanoic acid (PFOA), employing an in-situ synthesized polydopamine (PDA) interfacial layer. The optimal ratio was determined through molecular dynamics simulations. Various characterization techniques, including scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), were employed to comprehensively analyze the structure and elemental distribution of the samples. The findings indicate that the PDA coating process did not alter the surface structure of Al while maintaining the integrity of the functional groups of both PDA and PFOA. Results from simultaneous thermal analysis (TG-DSC) demonstrate that the PDA interfacial layer increased the pre-ignition reaction (PIR) peak temperature of PFOA/Al by 2 °C and enhanced the heat release of the PIR and fluorination reaction by 1.3 and 34.8 times, respectively. Thermal analysis kinetics investigation revealed a reduction of 6.66 kJ⋅mol−1 in the activation energy of the fluorination reaction and an increase of 20.28 kJ⋅mol−1 in the activation energy of the PIR. Furthermore, the combustion heat and reaction degree of PFOA/Al@PDA powder increased by 43.4 % and approximately 8 %, respectively, compared to PFOA/Al powder generated by physical mixing. This study demonstrated that the inclusion of PDA modifiers in the PFOA/Al system effectively controls the exothermic reaction between fuel and oxidant and enhances the oxidation degree of Al.

Adsorption of Congo red on magnetic cobalt-manganese ferrite nanoparticles: Adsorption kinetic, isotherm, thermodynamics, and electrochemistry.

Magnetic Co0.5Mn0.5Fe2O4 nanoparticles were successfully prepared via the combustion and calcination process, with an average particle diameter of 31.5 nm and a saturation magnetization of 25.25 emu·g-1, they were employed to adsorbe Congo red (CR) from wastewater, the Pseudo-second-order kinetic and Freundlich isotherm were consistent with the adsorption data, indicating that their adsorption was a multilayer chemisorption process, the thermodynamic investigation showed that the adsorption was a favored exothermic process. The ionic strength of Cl- in CR solution had no obvious effect on the adsorption efficiency of Co0.5Mn0.5Fe2O4 nanoparticles, and the maximum adsorbance was 58.3 mg·g-1 at pH 2, decreasing as the pH of the CR solutions increased from 2 to 12. The ion leaching experiment and XRD demonstrated that Co0.5Mn0.5Fe2O4 nanoparticles had excellent stability, and the relative removal rate was 93.85% of the first time after 7 cycles. Cyclic voltammetry and electrochemical impedance spectroscopy demonstrated that CR was adsorbed onto Co0.5Mn0.5Fe2O4 nanoparticles, and the electrical conductivity of Co0.5Mn0.5Fe2O4 nanoparticles decreased after adsorption of CR. Magnetic Co0.5Mn0.5Fe2O4 nanoparticles displayed a promising application in wastewater treatment.

Sodium alginate-based unsteady nanofluid flow over a porous stretching surface with endothermic and exothermic reaction and bioconvection effects

The impact of nanofluid (NF) circulation under gyrotactic microorganisms and endo/exothermic chemical reactions across a permeable medium is the primary emphasis of this investigation. Sodium Alginate and Silicon dioxide are the base fluid and nanoparticle utilised here. The governing equations are reduced to a set of ODEs by employing the appropriate similarity variables. To get the numerical results, the shooting method and Runge–Kutta Fehlberg's fourth fifth order (RKF-45) are implemented. The numerical outcomes are conveyed graphically across numerous parameters. In addition, the engineering factors are analyzed and explained. It was found that the velocity profile decreased with the enhanced Casson and porous parameter values. An increment in temperature profile is experienced during exothermic reaction and is reduced for endothermic reaction and also the concentration profile got accelerated as the impact of chemical reaction parameter is upsurged. There is a significant growth in surface drag force from NF to base liquid of about 2%, rate of thermal and mass distribution of about 0.1% in context to various constraints.

NaOH activated Galla chinensis residue hydrochar for the adsorption of methylene blue

To achieve the resource utilization of waste materials, this study utilized Galla chinensis residue (GCR) as a raw material to synthesize green hydrochar (HC) in one step, activated with NaOH to obtain alkali-activated hydrochar (AHC), which was then used for the adsorption of organic dye methylene blue (MB). The results showed that when the temperature was 25 °C, the pH was 7 and the MB concentration was 300 mg/L, the adsorption capacity (AC) of MB by AHC was 278.97 mg/g and the removal rate was 78.67 %. Langmuir (R2 = 0.9949) and the pseudo-second-order dynamics model (R2 = 0.9983) described the adsorption behavior of MB on AHC, which was an exothermic process according to thermodynamics. The adsorption mechanism included electrostatic attraction, hydrogen bond, π-π interaction, and the pore filling effect. Even after 5 cycles of adsorption–desorption, the AHC adsorbent maintained a high AC for MB, indicating that the HC prepared from GCR was a sustainable and promising adsorbent for MB, providing a new application direction for the reuse of GCR.

In-situ monitoring of changes in temperature and microstrain during the chemical corrosion of stone cultural relics

Temperature changes during the chemical corrosion of stone cultural relics affect the condensation and evaporation of water and chemical reactions between soluble substances and corrosive solutions. This ultimately leads to changes in the internal structure and composition of the artifacts, which in turn lead to changes in the microstrain of cultural relics. To obtain in-situ real-time information on changes in the temperature and microstrain of stone cultural relics during chemical corrosion damage, a fiber Bragg grating (FBG) detection system was developed. The detection principle for the temperature and microstrain of sandstone was provided. Thermal field emission scanning electron microscopy, X-ray diffraction, and mercury intrusion porosimetry were used to characterize the surface morphology, composition, and pore structure of the sandstone samples, respectively. The temperature and microstrain changes of the sandstone samples under deionized water with different acidic/alkaline and salt solutions and at different temperatures were examined online in situ using the FBG measurement system. The results indicate that the dissolution of sandstone in the acidic solution (H2SO4 and NaHSO4) resulted in an exothermic chemical reaction as well as the dissolution of sandstone in the neutral salt solution (Na2SO4) and alkaline solution (NaOH and Na2CO3) led to material conversion and exothermic chemical reaction; the deionization reaction belongs to the dissolution reaction. The NaHSO4 solution caused the most serious corrosive disease on the sandstone surface. When the temperature of the NaHSO4 solution was 60 °C, the temperature and microstrain of the sandstone reached 63.9 °C and 253.6 με, respectively. The results of this study can support the research of revealing the corrosion mechanism of sandstone in different environments.

An efficient carbon-neutral power and methanol polygeneration system based on biomass decarbonization and CO2 hydrogenation: Thermodynamic and economic analysis

This study presents a novel approach to enhance methanol synthesis (MS) efficiency through integration with an MEA-based decarbonized biomass direct-fired power plant (BFPP-CCS). The integration optimizes the utilization of chemical energy from feedstocks by combining exothermic MS reactions with diverse thermal energies, which effectively captures chemical energy through synergistic utilization from MS and various thermal inputs. Gradual methanol conversion maximizes both its chemical and fuel properties. Through such integration, the enhancement of waste heat and purge gas utilization in MS and BFPP carbon capture processes results in a 3.42 MW improvement in power generation and a 26.0 % reduction in associated energy penalties from CCS. Analysis of a 150 kton/yr MS facility and a 35 MW BFPP-CCS demonstrates 2.87 % increase in overall efficiency and reduction in CCS heat consumption by 1.03 GJ/tCO2. Moreover, this integrated approach yields a 33.1 M$ NPV increase and 3.4 years DPP decrease, achieving carbon-neutral power and liquid fuels production. Sensitivity analysis indicates the polygeneration system performs optimally around 250 °C and 60 bar, with a preference for 0.90 MS recycle ratio. Additionally, factors such as carbon recovery rate, electrolysis efficiency, and fixed carbon content in biomass are quantitatively revealed as crucial for maximizing carbon mitigation potential.

Thermal Analysis of Infrared Heater as an Alternative Heat Source for Flexitank Application Using CFD

The heating pad was a mechanism for heating elements using steam as a heat source and heating the liquid inside a flexitank to liquidise for easy discharge completely. Alternative heat sources such as infrared, electric, and exothermic reactions may improve thermal performance for the heating process. Infrared heating is chosen for this study due to its efficient radiation heat transfer compared to conduction and convection. This study aims to determine the optimal infrared heater configuration to improve the time to liquidify fluid on the flexitank for easier discharge. Nine flexitank and infrared heater geometries were made using SolidWorks with different heater positions and heating element thicknesses. Each geometry was simulated using Ansys Mechanical to study the thermal performance of radiation heat transfer with three different heating element materials. The heat output and energy input obtained from the simulation were used to calculate heating time and energy efficiency, respectively. The effects of each parameter were studied to determine the best configuration of the infrared heater in terms of heating time, energy consumption and both. The results showed that the position of the heater plays the most crucial role in determining the heating time and energy consumption, as a heater position that produces a larger heated surface area on the flexitank can reduce heating time. The thickness of the heating element and its material contributes a minor impact on heating time and energy consumption. Increasing thickness would lower the heating time and increase energy efficiency if the thickness improves heat retention capabilities. Increasing material emissivity will increase the heating time. Higher conductive materials would use more energy compared to lower conductive materials. The heating time was improved by about 30% compared to a steam heating pad. Energy consumption was reduced by about 85% compared to a small steam generator. In conclusion, the infrared heater was a promising alternative as a heat source for flexitank applications.

Improving heat transfer prediction across catalytic SiC interface through a multiscale framework leveraging machine learning and data fusion techniques

Accurate aerothermal prediction under hypersonic flow conditions is crucial for any thermal protection materials design and engineering. The surface catalytic effect, where dissociated atoms recombine into their molecular forms at the air-solid interface, is an exothermic reaction and plays an important role in high-enthalpy aerodynamic environment prediction. Taking SiC, a widely recognized high-temperature thermal protection material as an example, a multiscale fusion approach for aerothermal prediction is proposed. The approach utilizes reactive molecular dynamics method to construct an interface catalysis model, and the Bayesian maximum entropy to integrate experimental and simulational data into an optimized database. Subsequently, using the radial basis function neural network algorithm, a machine learning-based reaction kinetics model with precise analysis of surface catalysis is trained. The obtained catalytic recombination efficiency is used as a boundary input for computational fluid dynamics simulation, enabling rapid and accurate prediction of hypersonic thermal environment. The result shows that the predicted surface heat flux by this novel approach is consistent with the benchmark studies, but comes with significantly reduced computation time. The stagantion heat flux predictions based on the assumptions of full catalytic wall, finite rate catalytic wall (from the proposed multiscale fusion method), and non-catalytic wall are determined to be 8.65×106 W/m2, 7.51×106 W/m2, and 4.02×106 W/m2, respectively. Comparing these with the wind tunnel benchmark value of 7.48×106 W/m2, the error from the proposed multiscale fusion method is 0.30 %, indicating significant enhancement in prediction accuracy through the proposed upscaling method. The new approach could not only reveal complex exothermic reaction processes at the interface, but also enhance the prediction accuracy at much higher computational efficiency, providing an alternative for multiscale modeling of complex flow and heat transfer at the interface.

Inhibitory effects of polyphenols on the Maillard reaction in low lactose milk and the underlying mechanism

In this study, low lactose milk (LLM) was heat-treated under different conditions and stored at 4, 25 and 37°C for 15 d, after which the changes in the Maillard reaction (MR) of LLM were investigated. The contents of α-dicarbonyl compounds and 5-hydroxymethylfurfural(5-HMF) in LLM after the addition of polyphenols were determined via HPLC, and the inhibitory effects of 3 different concentrations of epigallocatechin gallate (EGCG), dihydromyricetin (DMY), and procyanidin (PC) on the MR of LLM were studied. The fluorescence intensity of LLM was measured at 290, 300 and 310 K, the fluorescence quenching types and binding constants of PC on casein were investigated, and thermodynamic analysis was carried out. These results suggest that the optimal heat treatment conditions were 80°C for 15 s and that the optimal storage conditions were 4°C. In the α-dicarbonyl compound capture and 5-HMF inhibition tests, PC had the greatest inhibitory effect at a concentration of 0.2 mg/mL, with an inhibition rate of 48.19%. Therefore, PC is more stable than the other 2 polyphenols. The mechanism of inhibition involves the formation of matrix complexes between PC and casein in LLM, resulting in static quenching of the LLM and thus a reduction of the inhibitory effect. The thermodynamic analysis revealed that the binding of PC to casein was an exothermic reaction, and the combination of the 2 was driven mainly by hydrogen bonding and van der Waals forces. This study lays a theoretical foundation for the development of LLM.

Spent Tea Leaves as an Adsorbent Material: Preparation, Characterization, and Application

The adsorption of Congo Red (CR) on the surface of Spent Tea Leaves (STL) was evaluated in an aqueous system. The study was carried out for the establishment of a standard wastewater treatment method that would remove reactive dyes by employing spent tea leaves as a bio-adsorbent. The effect of various parameters like amount of adsorbent, contact time, concentration of dye, and pH on the adsorption was studied. The adsorption capacity was monitored with a UV-visible spectrophotometer. The maximum adsorption of dye was observed at adsorbent mass of 3.5g /100 mL, at 8×10-5 M CR concentration, at pH = 9.72 and 50 minutes of contact time. The experimental results suggest that the adsorption of CR on the surface of STL is an exothermic process. The adsorption of CR on STL is found to follow pseudo first order kinetics. Based on the findings, it’s feasible to draw the conclusion that spent tea leaves would be a better adsorbent for the removal of reactive dyes from the wastewater.

Alkali Metal‐Doped Fullerenes as Hydrogen Storage—A Quantum Chemical Investigation

AbstractThe quest for alternative energy sources has been spurred by the drawbacks and environmental risks of fossil fuels, with hydrogen emerging as a viable contender. But finding materials that can effectively store hydrogen with the best adsorption energy is a major obstacle to building a hydrogen‐based economy. As a result, a significant amount of research has been conducted worldwide to examine fullerene's (C60) potential for hydrogen adsorption. The results of extensive DFT calculations are presented here, pertaining to the adsorption of hydrogen molecules onto fullerenes doped with alkali metals, namely Rubidium (Rb), Ceasium (Cs), and Fransium (Fr). The study analyzes a number of parameters, such as global properties, electronic, optical, and surface annihilation energy. These analyses are performed using the Gaussian 09 simulation package with the 6–31G/B3LYP level of theory DFT methodology. The findings show that an exothermic process is involved in the adsorption of hydrogen onto fullerene doped alkali elements, as evidenced by the negative adsorption energy. The attractive interactions between the polarized dipole of hydrogen molecules and the surface dipole of doped fullerenes can be the cause of this exothermicity. These results imply that fullerenes decorated with alkali metals are promising as likely hydrogen storage media.

Dual-functional MnS nanomaterials: Efficient adsorbent for phosphate removal and sonocatalyst for textile dye degradation

Naturally abundant, environmentally friendly alternatives for replacing the expensive lanthanum-based phosphate removal technique are sought after. Solocatalysis is an emerging area for water remediation. This study introduces a dual-functional MnS nanomaterial for removing phosphate ions and Congo Red textile dye. MnS nanomaterials were synthesized via a hydrothermal route. Batch adsorption experiments revealed a phosphate adsorption capacity of 160.73 mg P/g, commendable for adsorbent in its bare form. Thermodynamic parameters of the process indicated a spontaneous, exothermic process, confirming favourable adsorption. FTIR analysis confirmed the adsorption mechanism, which includes electrostatic attraction, surface complexation, and ion exchange. MnS maintained its adsorption capacity despite competing ions, demonstrating a selective affinity for phosphate ions. MnS showed high sonocatalytic efficiency, degrading Congo Red dye within 10 min of ultrasonic irradiation. The degradation mechanism of Congo Red dye in the sonocatalytic process is proposed. This novel metal chalcogenide material exhibits exceptional affinity for phosphate ions and Congo Red dye molecules, surpassing La-based adsorbents in efficacy. The results suggest that MnS nanomaterials are promising for practical applications in phosphate removal and textile dye degradation from wastewater.