Adsorption Band Research Articles

Solvent assisted mechanochemical synthesis, antimicrobial and antioxidant studies of Ni2+, Mn2+, Cr<sup>2+</sup> , and Cu<sup>2+</sup> Metal complexes of some ligands derived from l-histidine and l-alanine

Mechanochemistry enables rapid, quantitative reactions to occur at or close to 27℃. It is a one-step process that allows for reactant homogenization, product nucleation, and particle growth. These processes use little or no solvent, making them less wasteful and more environmentally friendly than solvent-based reactions. Ni2+ , Mn2+, Cr2+and Cu2+ metal ions were synthesized by grinding in an agate mortar with pestle using ligands derived from amino acids (Histidine &Alanine) which were further synthesized to form complexes. The entire experiment was carried out by solvent solvent-assisted mechanochemical process and ethanol was used as liquid liquid-assisted solvent. The complexes were characterized by IR spectroscopy, U-V spectroscopy, X-ray analysis, melting point, solubility test, and conductivity measurement. The Solubility test showed that the complexes are soluble in DMSO, DMF, and ethanol and are insoluble in both hexane and tetrachloromethane. The molar conductivity values are in the range of (6.05-28.56) Ω-1cm2mol-1 ) indicating the complexes behave as non-electrolytes. IR analysis showed a vibrational frequency band observed at (1620-1625) cm-1 which is assigned to the ʋ(C=N) of the azomethine, also the new bands M=N, M=O indicate the coordination reaction between the metal and the ligands. The UV visible analysis shows various transitions, the metal complexes showed adsorption bands at λ of 420 and 575nm respectively because of the ligand-to-metal charge transfer (LMCT). The XRD analysis showed that there was a change in phase between the starting material and the product which indicate that a reaction occurred, also the nature of the spectra showed that the compounds are all crystalline. The Antimicrobial activity showed that both the complexes and the ligands have good activity against the bacterial isolates. Antioxidant activity was also tested and the compound appeared to have moderate scavenging activities compared to the reference used. The values indicated that the activities are more pronounced when coordinated with metal ions.

Group VIII Transition Metal (Fe, Ru & Os) Embedded Graphitic Carbon Nitride as an Acetone Sensor: A First Principle Investigation

This study investigates the acetone sensing behavior of pristine graphitic carbon nitride (gCN) and group VIII transition metal (Fe, Ru & Os) embedded gCN monolayer using DFT calculations. Key structural and electronic properties such as adsorption energy, band structure, and density of states (DOS) have been examined. The calculated adsorption energy of pristine gCN is −1.32 eV, which improves to –3.52, −2.75, and −1.73 eV for Fe, Ru, and Os embedded gCN, respectively. The band structure also indicates a reduction in the band gap of gCN after acetone adsorption due to the introduction of Fe, Ru, and Os. Furthermore, after the adsorption of acetone, the DOS values exhibit a significant increase from 13.48 eV−1 for pristine gCN to 439, 423, and 332 eV−1 for Fe, Ru, and Os embedded gCN, respectively.

Synergistic enhancement of the photocatalytic activity of g-C3N4 via in-situ surface alkalization and CQDs loading strategies

The CQDs/alkaline carbon nitride heterojunction photocatalysts were synthesized employing dicyandiamide as the nitrogen material, Citric acid was used as the carbon source, while KCl and NH4Cl were as alkaline reagents. The study investigated the influence of CQDs on the adsorption performance, photocatalytic activity, and band structure of alkalized carbon nitride. The dark adsorption results revealed that CNK/CQDs1: 12 exhibited outstanding adsorption performance, capable of degrading adsorbed pollutants in a relatively short period. The photocatalytic degradation study demonstrates that CNK/CQDs1:12 exhibits significantly higher degradation efficiencies compared to the pristine CN and alkalinized CNK samples, with degradation efficiencies of 94.4 % for Methylene Blue (MB) and 71.68 % for tetracycline hydrochloride (TC-HCl) within 60 min. This is due to the synergistic effects of alkalization of the g-C3N4 surface and CQDs loading, which modified the heterojunction interfacial charge transfer efficiency, suppressing the recombination of photoelectron-hole pair, extending the life span of transient photogenerated carriers, thereby improving photocatalytic activity. Free radical trapping experiment indicated that h+ and ·O2− are the primary active species during the photocatalytic degradation process of CNK/CQDs1:12.

Removal of oxytetracycline from pharmaceutical wastewater using kappa carrageenan hydrogel

This study investigated the adsorption of Oxytetracycline (OTC) from pharmaceutical wastewater using a kappa carrageenan based hydrogel (KPB). The aim of the present study was to explore the potential of KPB for long-term pharmaceutical wastewater treatment. A sustainable adsorbent was developed to address oxytetracycline (OTC) contamination. The hydrogel’s structural and adsorption characteristics were examined using various techniques like Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR), X-ray powder diffraction (XRD), and kinetic models. The results revealed considerable changes in the vibrational modes and adsorption bands of the hydrogel, suggesting the effective functionalization of Bentonite nano-clay. Kappa carrageenan based hydrogel achieved the maximum removal (98.5%) of OTC at concerntration of 40 mg/L, pH 8, cotact time of 140 min and adsorbent dose of 0.1 g (KPB-3). Adsorption of OTC increased up to 99% with increasing initial concentrations. The study achieved 95% adsorption capacity for OTC using a KPB film at a concentration of 20 mg/L and a 0.1 g adsorbent dose within 60 min. It also revealed that chemisorptions processes outperform physical adsorption. The Pseudo-Second-Order model, which emphasized the importance of chemical adsorption in the removal process, is better suited to represent the adsorption behavior. Excellent matches were found that R2 = 0.99 for KPB-3, R2 = 0.984 for KPB-2 and R2 = 0.989 for KPB-1 indicated strong chemical bonding interactions. Statisctical analysis (ANOVA) was performed using SPSS (version 25) and it was found that pH and concentration had significant influence on OTC adsorption by the hydrogel, with p-values less than 0.05. The study identified that a Kappa carrageenan-based hydrogel with bentonite nano-clay and polyvinyl alcohol (PVA) can efficiently remove OTC from pharmaceutical effluent, with a p-value of 0.054, but weak positive linear associations with pH, temperature, and contact time. This research contributed to sustainable wastewater treatment and environmental engineering.

Theoretical Study of Dissolved Gas Molecules in Transformer Oil Adsorbed on Intrinsic and TM (Ta, V)-Doped MoTe2 Monolayer.

In this paper, CH4, C2H2, H2, and CO adsorbed on intrinsic MoTe2 monolayer and transition metal atom (Ta, V)-doped MoTe2 monolayer have been investigated with density functional theory based on first-principles study. The adsorption energy, geometries, band structures, and density of states of four gases (CH4, C2H2, H2, and CO) adsorbed on the MoTe2 and doped MoTe2 surfaces were analyzed. The results shown that the gas adsorption performance of transition metal atom (Ta, V)-doped MoTe2 monolayers is more superior than that of intrinsic MoTe2, and the adsorption energy and charge transfer of the adsorbed gases on the TM-MoTe2 monolayer are significantly increased in comparison with both sides. Among them, Ta-MoTe2 has the largest Eads value in the adsorbed CO system with a very small adsorption distance, as well as a more suitable recovery time of CO at room temperature, so Ta-MoTe2 can be a candidate material for CO detection. New atoms were introduced during the doping process, which increased the carrier density and carrier mobility of the material, thus improving the charge transfer at the surface of the material. which provides a direction for the gas-sensitive properties of metal Ta-modified MoTe2 materials.

A new design of colorimetric films using bacterial cellulose nanocrystals derived from nata de coco for sensing volatile organic compounds

In this work, bacterial cellulose (BC) derived from Nata de Coco is a polysaccharide material, and it is further processed into bacterial cellulose nanocrystal (BCNC) via acid hydrolysis. Then BCNC is doped with transition metals to enhance its amine/hydrogen sulfide response. Therefore, the aim of this study is to investigate the use of transition metals as indicators to detect amine and hydrogen sulfide gas for efficiently monitoring food spoilage. BCNCs were treated with various concentrations of silver nitrate (AgNO3) and copper sulfate pentahydrate (CuSO4·5H2O). Then the dropwise addition of ascorbic acid was applied to reduce Ag+ and Cu2+ to Ag0 (silver nanoparticle) and Cu0 (copper nanoparticle), which refer to red brown and red wine colors, respectively. The results indicated that BCNC/Ag nanoparticles were spherical, while BCNC/Cu nanoparticles exhibited a rod-like structure. XRD results also presented the incorporation of Ag and Cu nanoparticles, as confirmed by both crystallography structures. Furthermore, UV–Vis spectra showed the adsorption bands at 422–430 nm and 626–629 nm, belonging to Ag and Cu nanoparticles. After H2S and ammonia gas exposure, BH/Ag and BH/Cu films turned black from brown and red. In conclusion, transition metal-doped BCNCs exhibit potential for innovative food spoilage gas sensors.

Displacement chromatography of gadolinium isotopes with strong cation exchange resin using 1,2-cyclohexanedinitrilotetraacetic acid (CDTA)

Adsorptive separation of Gd3+ ions was evaluated using DOWEX-50×8 ion exchange resin. It has shown a maximum adsorption capacity of 228.50 mg/g at optimum pH 5 and room temperature. Separation of Gd isotopes was investigated using packed bed columns of the resin in displacement chromatographic techniques where 1,2-cyclohexanedinitrilotetraacetic acid was used as displacer in the mobile phase. Isotopic analysis data by using MC‒ICP‒MS confirmed that the front end of the Gd adsorption band exhibited enrichment of the heavier isotope (160Gd), while the lighter isotopes (157Gd and 155Gd) were concentrated at the rear end of the stationary phase.

Adsorption and gas sensing properties of Pdn(n=1–3) cluster-modified PtSe2 on transformer fault characterizing gases under biaxial strain and electric field

In this study, the adsorption behavior of three DGA gases (C2H2, C2H4, and CO) on monolayers of PtSe2 doped with metal clusters Pdn(n=1–3) was investigated using density-functional theory (DFT). The critical influence of the Pd clusters on the sensitivity of PtSe2 gas is revealed by in-depth analysis of the geometrical structure of the adsorption system, DCD, ELF, DOS and band gap. The results show that the detection performance of intrinsic PtSe2 monolayer is poor. However, the doping of Pdn(n=1–3) fundamentally changes the adsorption behavior of PtSe2 on C2H2 and C2H4 from an adsorptive to an exothermic reaction, and endows it with excellent adsorption, desorption, and gas sensitivity properties. In addition, the introduction of external electric field and biaxial strain can significantly change the charge transfer, band gap, and adsorption energy of each adsorption system, which suggests that the Pdn(n=1–3)-PtSe2 monolayer has excellent tunability and can be strain-modulated for gas detection.

First principles study of transition metal (TM = Sc, Ti, V, Cr, Mn) doped penta-BAs5 monolayer for adsorption of CO, NH3, NO, SO2

In this paper, the adsorption capacity of intrinsic penta-BAs5 monolayer on CO, NH3, NO, SO2 and the effect of transition metal doping on gas sensing characteristics are systematically studied by first-principles calculations. Adsorption energy, recovery time, band structure, charge transfer and density of states (DOS) are investigated. The electronic properties and sensing mechanisms under different adsorption systems are expounded. The results showed that the intrinsic penta-BAs5 monolayer had the strongest adsorption capacity for NO and weak sensitivity to CO, NH3 and SO2, which shown strong gas selectivity. Moreover, the recovery time of NO at 380 k was 3.93 s, which was more inclined to be desorption at high temperature. In addition, Sc and Ti doping could selectively improve the adsorption capacity of the intrinsic penta-BAs5 monolayer. The charge transfer of SO2-Sc-BAs5 and CO-Ti-BAs5 were increased by 6.78 and 10.33 times compared with those before doping. The band structure and DOS show that Ti atom and CO have orbital hybridization, which improved the interaction between gases and penta-BAs5. Therefore, intrinsic penta-BAs5, Sc-BAs5 and Ti-BAs5 are suitable for gas sensing and toxic gas monitoring, and have broad application prospects.

Fluorescent porous hybrid silsesquioxane-based semiconductor polymer for sunlight-driven gold recovery with high efficiency and selectivity

As an important precious metal, the recovery of gold can not only relieve the shortage of resources, but also has a high economic value. In this work, a novel silsesquioxane-based fluorescent porous hybrid polymer (PTSC) was prepared successfully by Heck coupling reaction of octavinylsilsesquioxane with a dibromated distyry-bithiophenes containing cyano groups. The structure of PTSC was fully investigated, which featured a high surface area of 455 m2 g−1, wide light adsorption band, narrow optical band gap (1.73 eV) and excellent semiconductor performance. As Au(III) adsorbent, the adsorption capacity of PTSC reached 3080 mg g−1 under light irradiation for 4 h at pH = 5, and the purity of the recovered gold in e-waste could reach 23.92 K. The adsorption mechanism showed that photoelectrons produced by PTSC could reduce all Au(III) adsorbed to Au(I) and Au(0). Moreover, a hybrid aerogel device based on PTSC and chitosan was fabricated to realize the enrichment and recovery of gold ions in wastewater. Besides, PTSC could also act as a probe to detect Au(III) with high selectivity and specificity. This study provided a new strategy for efficient recovery and detection of Au(III).

Synergistic effects of β-NaFeO2 ferrite nanoparticles for photocatalytic degradation, antibacterial, and antioxidant applications.

Here, synthesis and thorough characterization of β-NaFeO2 nanoparticles utilizing a co-precipitation technique is presented. XRD analysis confirmed a hexagonal-phase structure of β-NaFeO2. SEM revealed well-dispersed spherical nanoparticles with an average diameter of 45 nm. The FTIR spectrum analysis revealed weak adsorption bands at 1054 cm-1 suggested metal-metal bond stretching (Fe-Na). UV-Visible spectroscopy indicates a 4.4 eV optical band gap. Colloidal stability of β-NaFeO2 was evidenced via Zeta potential (-28.5 mV) and Dynamic Light Scattering (DLS) measurements. BET analysis reveals a substantial 343.27 m2 g-1 surface area with mesoporous characteristics. Antioxidant analysis indicates efficacy comparable to standard antioxidants, while concentration-dependent antibacterial effects suggest enhanced efficacy against Gram-positive bacteria, particularly Streptococcus. The Photocatalytic activity of β-NaFeO2 showed significant pollutant degradation (>90% efficiency), with increased degradation rates at higher nanoparticle concentrations, indicating potential for environmental remediation applications.

DFT Study of Metal (Ag, Au, Pt)-Modified SnS2 for Adsorption of SF6 Decomposition Gases in Gas-Insulated Switchgear.

In this study, the gas-sensitive response of metal (Ag, Au, Pt)-modified SnS2 toward SF6 decomposition gases (SOF2, SO2F2, SO2, H2S) in gas-insulated switchgear was studied by analyzing the adsorption structure, band structure, charge transfer, and density of states based on density functional theory. The results show that the adsorption of the four target gases on pristine SnS2 belongs to weak physical adsorption. Compared with the pristine SnS2, the adsorption energy of the transition metal atom-modified SnS2 monolayer has been improved to a certain extent and the adsorption capacity of these four gases on the transition metal atom-modified SnS2 monolayer has obviously improved. Moreover, the recovery time of Ag-SnS2/SOF2, Ag-SnS2/SO2F2, Au-SnS2/SOF2, Au-SnS2/SO2F2, and Pt-SnS2/SO2F2 is too short, indicating that these conditions have poor adsorption capacity and sensitivity to SF6 decomposition gases and are not suitable as detection materials for these gases. According to the different changes in conductivity during adsorption, it provides a feasible solution to detect each SF6 decomposition gas. This theoretical study effectively explained the adsorption and sensing properties between the metal-modified monolayers and gases.

First-principles study on structural and electronic properties of P3HT-graphene

Based on density functional theory, calculations have been carried out to study the structural and electronic properties of the polymer Poly (3-hexylthiophene) (P3HT) interacting with monolayer graphene as an active layer. (P3HT)1-graphene and (P3HT)2-graphene are optimized on graphene using the generalized-gradient-approximation type of the exchange-correlation functional. Adsorption energy, band gap, and charge transfer are calculated. The calculated adsorption energy shows that all systems have negative adsorption energy, indicating that the reaction is exothermic. Compared to (P3HT)1-graphene, (P3HT)2-graphene has a lower band gap. As for the charge transfer calculation, a negative ΔN indicates that electron transfers from P3HT to graphene.

Unravelling the influence of surface functional groups and surface charge on heavy metal adsorption onto carbonaceous materials: An in-depth DFT study

Theoretical analyses were explored for the adsorption of heavy metals in aqueous systems, focusing on the influence of surface charge and functional groups of carbonaceous materials. The approach involved the meticulous assignment and interpretation of active adsorption bands, achieved through modelling of Fourier Transform Infrared (FT-IR) and X-ray Photoelectron Spectroscopy (XPS) spectra. Additionally, atomic charges were analyzed, utilizing their chemical properties to glean valuable insights into the atomic-level intricacies of the adsorption process. The structural parameters of the carbonaceous surface reveal that in unsaturated models, heavy metals preferentially adsorb onto neighboring carbons due to facilitated electron transfer. Conversely, adsorption predominantly occurs in saturated models within functional groups, except for interactions involving the phenolic group, where it occurs on the carbonaceous matrix. Overall, negative ΔG values were observed across a range of temperatures from 285 to 315 K, as evidenced by Gibbs free energy values ranging from −72.93 kcal/mol (Ni2+ on carboxylate) to −4.98 kcal/mol (Cd2+ on ketone), confirming the spontaneous and thermodynamic feasibility nature of the adsorption processes for heavy metals on biochar across all evaluated functional groups, following the trend Ni2+ > Zn2+ > Co2+ > Cd2+. These trends can be rationalized in terms of: a) the size-dependence, where smaller cations such as Ni2+ (0.69 Å) form more stable adsorption complexes than Cd2+ (0.95 Å); b) charge transfer, higher adsorption energy (-55.60 kcal/mol) corresponds to a greater magnitude of charge transfer (0.32e); and c) the electronegativity of the respective metals, which are as follows: 1.367 for Ni2+, 1.349 for Co2+ and 1.336 for Zn2+. Consequently, Ni2+ exhibits a greater propensity to accept electrons from oxygen biochar than Co2+ and Zn2+ atoms. Finally, the assignment of IR and XPS is challenging in the laboratory, facing several endeavours. Our findings indicate a notable shift in the C―O stretching signal from 1631 cm−1 (in the clean system) to 1652 cm−1 upon Cd2+ adsorption, with Co2+, Ni2+, and Zn2+ showing shifts to 1690 cm−1 and 1685 cm−1 for the latter two cases, respectively. Therefore, the theoretical signals reported in the current work are a helpful tool as benchmark data to address and complement further experimental information. Indeed, the modelling of IR and XPS fit with some experimental values for some representative cases, implying appropriate modelling of the above systems.

Investigation of olfactory perception by a putative adsorption process of sotolone and abhexone on human olfactory receptor OR8D1: Statistical physics modeling and molecular docking

In the present paper, a double layer advanced model was used to investigate the adsorption process putatively involved in the olfactory perception of sotolone and abhexone molecules on the human olfactory receptor OR8D1. The number of adsorbed molecules or the fraction of adsorbed molecule per site, n, informed that the two odorants molecules are docked on OR8D1 binding sites with mixed parallel and nonparallel anchorages. Furthermore, the estimated molar adsorption energy (−ΔE1 and −ΔE2) were inferior to 40 kJ/mol for the two adsorption systems, which confirmed the physical nature and the exothermic character of the adsorption process. In addition, stereographic characterizations of the receptor sites surface were carried out through the determination of the receptor site size distribution (RSDs) via Kelvin equation, which spread out from 0.05 to 1.5 nm. The adsorption energy distributions (AEDs) via Polayni equation show an adsorption band spectrum localized between 17 kJ/mol and 22.5 kJ/mol for sotolone and abhexone molecules respectively. A molecular docking calculation was performed. The results indicate that the binding affinities are belonging to the spectrum of the energy band of the molecules sotolone and abhexone, with values 19.66 kJ/mol and 19.24 kJ/mol.

The synthesis and efficient electromagnetic wave absorption properties of RE-MOF microcrystals

Electromagnetic interference is considered as a potential crisis for human health and social development. Therefore, the exploration of novel electromagnetic wave absorption (EMWA) materials with the characteristics of “Thinner”, “Wider”, “Lighter”, “Stronger” is desired. Compared with traditional materials, metal organic frameworks (MOFs) as the emerging hybrid materials, can better meet these requirements. Here, two rare-earth metal based MOFs microcrystals with regular octahedral morphology (size about 15–20 µm), namely MOF 1 and MOF 2 were successfully fabricated. The derived carbon materials, which remained stable octahedral morphology were obtained by carbonization of as-synthetized MOFs at 450 °C under the N2 atmosphere, named complex 1 and complex 2. Further investigation manifested that carbonization could effectively enhance the EMWA performance of these MOFs. Complex 1 attained the minimum RL value of − 23.22 dB and a broad effective adsorption bands(EAB) of 5.76 GHz. Similarly, the minimum RL value for complex 2 attained − 22.31 dB under the thickness of 2.5 mm with the broad EAB of 4.16 GHz.

Ultraviolet enhanced inorganic graphenylene-like ZnMgX2 (X=O, S) for sensitive and reversible detection of toxic formaldehyde at room temperature: A first-principles study

This study investigates the interaction between formaldehyde (HCHO) and newly predicted graphenylene-like ZnMgX2 (X=O, S) monolayers based on first-principles calculations. It was found that the adsorption performance of HCHO molecule on pure ZnMgX2 monolayers was favorable and exothermic in nature, exhibiting no need for the presence of a metal support. Their experimental feasibility was proven through various analyses, including the evaluation of cohesive energy, phonon dispersion and ab initio molecular dynamics (AIMD) simulations. The results of the topological analysis indicate that the examined monolayers are stabilized by the mixed ionic-covalent bond. By systematically analyzing the adsorption energy, charge transfer, band gap, work function and presence of competing gases (H2O, N2, O2 and H2), their detection sensitivity and response times were determined. Under the presence of ultraviolet (UV) irradiation, the ZnMgO2 system demonstrates suitability as an electronic sensor for HCHO detection at room temperature, while ZnMgS2 with its large adsorption energy has the potential to be used for scavenging HCHO. Further investigation into the adsorption of H2O and O2 yields supporting evidence for high selectivity and improved recovery time of HCHO and potential formation of hydroxyl (•OH) and superoxide (O2•−) radicals, thereby establishing favorable conditions for eventual catalytic degradation of HCHO. This study will serve as a theoretical foundation for the development of HCHO gas sensors intended for both small-scale and industrial applications.

Metal-injection and interface density engineering induced nickel diselenide with rapid kinetics for high-energy sodium storage

The key to the innovation of sodium-ion batteries (SIBs) is to find efficient sodium-storage electrode. Here, metal Mo doping of NiSe2 is proposed by modified electrospinning strategy followed by in situ conversion process. The Mo-NiSe2 anchoring on hollow carbon nanofibers (HCNFs) would make full use of the multi-channel HCNFs in the inner layer and the active sites of Mo-NiSe2 in the outer layer, which plays an important role in buffering the volume stress of Na+ (de)insertion and reducing the adsorption energy barrier of Na+. Innovatively, it is proposed to jointly regulate the SIBs performance of NiSe2 by both metal atom doping and interface effects, thereby adjusting the sodium ion adsorption barrier of NiSe2. The Mo-NiSe2@HCNFs exhibits remarkable performance in SIBs, demonstrating a high specific capacity of 396 mAh/g after 100 cycles at 1 A/g. Moreover, it maintains outstanding cycling stability, retaining 77.6 % of its capacity (211 mAh/g) even after 1000 cycles at 10 A/g. This comprehensive electrochemical performances are due to the structural stability and outstanding electronic conductance of the Mo-NiSe2@HCNFs, as evidenced by the diffusion analysis and ex situ charge–discharge process characterization. Furthermore, coupled with the Na3V2(PO4)2O2F cathodes, the full cell also achieves a high energy density of 123 Wh kg−1. The theoretical calculation of the hypervalent Mo doing further proves the benefit of its Na+ adsorption and denser conduction band distribution. This study provides a reference for the construction of transition metal selenide via doping and interface engineering in sodium storage.

Augmented Catalytic Performance of PVA- Assisted Fe2O3 Nano Catalyst for Water Treatment Synthesized via Green Route

Abstract Metal oxides (MO) are widely preferred for removing various effluents from water and air; however due to poor utilization of visible light, the application of MO nanoparticles for water treatments is hindered. This work reports the synthesis of ring-structured PVA-assisted Fe2O3 (P-Fe2O3) nanocomposite through a green route synthesis, for the elimination of methylene blue via sunlight triggered photocatalyst. FTIR spectroscopy confirmed the presence of desired functional groups in novel ring-structured Fe2O3 and PVA-assisted Fe2O3 (P-Fe2O3) nanocomposite. The crystallinity of Fe2O3 was also studied through XRD. Surface topography of Fe2O3 was examined through FE-SEM, that reveals a central hole with extended surface area of Fe2O3. UV-vis-spectroscopy is used to evaluate photocatalytic efficiency which shows, pristine Fe2O3 exhibited 37% degradation in stipulated time intervals of 30~120 mins. The photocatalytic efficiency of augmented P-Fe2O3 nanocomposite expelled 82% of the methylene blue in span of just 02 hours. The stability of the developed nanocomposite in the effluent medium was investigated through FTIR by observing the change in carboxyl adsorption band produced during degradation of PVA, that manifests the fact that no degradation was witnessed for PVA even after 120 min, that makes P-Fe2O3 a promising material for the degradation of AZO dyes.

Sustainable synthesis of tunable 2D porous carbon nanosheets toward remarkable electromagnetic wave absorption performance

The realization of microwave absorbers that demonstrate wide frequency bands and strong absorption properties, especially for realizing multi-band absorption characteristics, presents an ongoing challenge in the field. Herein, we reported on a simple and sustainable method for the fabrication of gram-scale B/N co-doped porous carbon nanosheets (PCNs). These PCNs exhibited excellent microwave absorption performance, and their intrinsic electromagnetic wave absorption performance can be tuned by adjusting the size of nanosheets and heteroatoms. The PCNs achieved dual-band absorption in the C- and Ku- bands. Furthermore, the GC20 achieved an RLmin value of −29.5 dB at a thickness of 1.7 mm, with an effective adsorption band (EAB) of 7.2 GHz. The porous nanosheets, which provide the ideal synergistic effect of polarization loss and conductivity loss, were the factors that contributed to these desirable features. These absorbers with multi-band absorption are not only expected to address the prevalent issue of narrow EAB but also fulfill the requirements for applications in the different frequency bands, inspiring innovative designs of multi-band electromagnetic absorbers.