Targeted and Enhanced Antimicrobial Inhibition of Mesoporous ZnO-Ag2O/Ag, ZnO-CuO, and ZnO-SnO2 Composite Nanoparticles

Impact of Iron Oxide Phases on the Magnetic Induction Heating Capacity of Mesoporous 45SiO2-16.5CaO-24.5Na2O-6P2O5-8Fe3O4 Glass-Ceramics

Sol-gel-based mesoporous 45SiO2-16.5CaO-24.5Na2O-6P2O5-8Fe3O4 bioglass-ceramics were obtained by substituting magnetite nanoparticles for CaO in a 45SiO2-24.5CaO-24.5Na2O-6P2O5 bioglass composition. To enhance the dissolution of the precursors and to vary the crystalline phases, the as-synthesized ceramic powders were processed for 1 h each at temperatures (TA) between 550 and 700 °C. A gradual decline in the saturation magnetization with an increase in TA was observed, which is linked to the gradual conversion of magnetite into hematite at different TA > 550 °C. All of the processed samples indicated a hydroxyapatite surface layer formation in in vitro tests. Aqueous solutions of the ceramic processed at 600 °C exhibited superior magnetic induction capacity. Thus, the substitution of magnetite nanoparticles for CaO in the base composition, coupled with appropriate heat treatment, results in a promising bioactive glass-ceramic for magnetic hyperthermia treatment of deep-rooted cancer cells.

In Situ Electrochemical Cobalt Doping in Perovskite-Structured Lanthanum Nickelate Thin Film Toward Energy Conversion Enhancement of Polymer Solar Cells

This study demonstrates that the electrochemical doping of lanthanum nickelate (LNO) with cobalt ions is a promising strategy for enhancing its physical and electrochemical properties, which are critical for energy storage and conversion devices. LNO emerges as a promising hole transport layer (HTL) in solar cells due to its stability, large band gap, and high transparency. Nevertheless, its low conductivity and improperly aligned band positions are persistent problems. Here, in a pioneering endeavor, Co-doped LNO thin films were synthesized electrochemically and applied as the HTL in polymer solar cells (PSCs). Characterization revealed the impact of Co doping on the electrochemical, structural, morphological, and optical properties of LNO thin films. Depending on the Co doping level, PSCs based on 10 mol % Co-doped LNO outperformed pure LNO, achieving a champion efficiency of 6.11% with enhanced short-circuit current density (12.84 mA cm-2), fill factor (68%), open-circuit voltage (0.70 V), and external quantum efficiency (82.6%). This enhancement resulted from decreased series resistance, refined surface morphology, minimized trap-assisted recombination, enhanced conductivity, increased charge carrier production, favorable energy level alignment, and improved current extraction facilitated by LNC0.10O HTL. Moreover, the unencapsulated PSC-LNC0.10O long-term stability notably improved and retained 86% of its initial PCE after 450 h storage in ambient air, 82% after being continuously heated to 85 °C for 300 h, and 80% after operating at maximum power point for 300 h. These findings offer a straightforward approach to enhancing PSC performance through Co doping of LNO, supported by density functional theory (DFT) calculations that validate the experimental results and confirm the improvement in optical properties and stability of PSCs as an HTL.

Zinc Oxide-Based Nanomaterials for Microbiostatic Activities: A Review

The world is fighting infectious diseases. Therefore, effective antimicrobials are required to prevent the spread of microbes and protect human health. Zinc oxide (ZnO) nano-materials are known for their antimicrobial activities. Because of their distinctive physical and chemical characteristics, they can be used in medical and environmental applications. ZnO-based composites are among the leading sources of antimicrobial research. They are effective at killing (microbicidal) and inhibiting the growth (microbiostatic) of numerous microorganisms, such as bacteria, viruses, and fungi. Although most studies have focused on the microbicidal features, there is a lack of reviews on their microbiostatic effects. This review provides a detailed overview of available reports on the microbiostatic activities of ZnO-based nano-materials against different microorganisms. Additionally, the factors that affect the efficacy of these materials, their time course, and a comparison of the available antimicrobials are highlighted in this review. The basic properties of ZnO, challenges of working with microorganisms, and working mechanisms of microbiostatic activities are also examined. This review underscores the importance of further research to better understand ZnO-based nano-materials for controlling microbial growth.

Synthesis and Characterization of the Zinc-Oxide: Tin-Oxide Nanoparticle Composite and Assessment of Its Antibacterial Activity: An In Vitro Study

Introduction Nanoparticles (NPs) have been widely used for biomedical applications. Various methods of synthesis of NPs have been performed and the sol-gel technique is one of the most common and feasible methods. ZnO and SnO2 NPs are widely used due to their interesting properties and versatile medical applications. The present study aimed to synthesize a composite of ZnO- SnO2 NPs and evaluate its structural, morphological, and antibacterial properties. Materials and methods ZnO-SnO2 NPs were prepared via the sol-gel technique. The morphological study was performed by scanning electron microscopy (SEM) imaging, the structural study was performed by X-ray diffraction (XRD) analysis, and chemical studies were performed by Fourier transform infrared spectroscopy (FT-IR) and energy-dispersive X-ray spectroscopy (EDAX). Antibacterial properties of the NPs were assessed by the agar diffusion test and the area of bacterial growth that was inhibited was measured under high and low concentrations of the NPs. Results The SEM analysis confirmed the irregular shape and elemental composition of the synthesized NPs. The purity of the NPs was confirmed by the EDAX spectrum, which indicates the weight percentages of the elements in the NPs as follows: Sn-53.8%, Zn-12.5%, O-29.1%, and C-4.7%. The chemical bonds between the NPs were confirmed by Fourier transform infrared spectroscopy. XRD analysis confirmed the high degree of crystallinity of the NPs and orthorhombic structure of SnO2 and the hexagonal structure of ZnO. The zone of inhibition against S. aureus, S. mutans, and E. coli for low concentrations of the NPs was 24 mm, 26 mm, and 30 mm and for high concentrations of the NPs it was 26 mm, 28 mm, and 31mm and these values were similar to the control antibiotics.  Conclusion ZnO- SnO2 NPs were successfully prepared by the sol-gel method. The presence of NPs was confirmed and successfully characterized. The prepared NPs had a good antimicrobial effect against the tested pathogens.

Nickel-iron doped on granular activated carbon for efficient immobilization in biohydrogen production

Nickel-iron doped granular activated carbon (GAC-N) was used to enhance immobilization in biohydrogen production. The effect of the sludge ratio to GAC-N, ranged 1:0.5-4, was studied. The optimum hydrogen yield (HY) of 1.64 ± 0.04 mol H2/mol sugar consumed and hydrogen production rate (HPR) of 45.67 ± 1.00 ml H2/L.h was achieved at a ratio of 1:1. Immobilization study was performed at 2 d HRT with a stable HY of 2.94 ± 0.16 mol H2/mol sugar consumed (HPR of 83.10 ± 4.61 ml H2/L.h), shorten biohydrogen production from 66 d to 26 d, incrementing HY by 57.30 %. The Monod model resulted in the optimum initial sugar, maximum specific growth rate, specific growth rate, and cell growth saturation coefficient at 20 g/L, 2.05 h-1, 1.98 h-1 and 6.96 g/L, respectively. The dominant bacteria identified was Thermoanaerobacterium spp. The GAC-N showed potential as a medium for immobilization to improve biohydrogen production.

Emerging Mesoporous Polyacrylamide/Gelatin-Iron Lanthanum Oxide Nanohybrids towards the Antibiotic Drugs Removal from the Wastewater

The polyacrylamide/gelatin-iron lanthanum oxide (P-G-ILO nanohybrid) was fabricated by the free radical grafting co-polymerization technique in the presence of N,N-methylenebisacrylamide (MBA) as cross linker and ammonium persulfate (APS) as initiator. The P-G-ILO nanohybrid was characterized by the various spectroscopic and microscopic techniques that provided the information regarding the crystalline behavior, surface area, and pore size. The response surface methodology was utilized for the statistical observation of diclofenac (DF) adsorption from the wastewater. The adsorption capacity (qe, mg/g) of P-G-ILO nanohybrid was higher (254, 256, and 258 mg/g) than the ILO nanoparticle (239, 234, and 233 mg/g). The Freundlich isotherm model was the best fitted, as it gives the higher values of correlation coefficient (R2 = 0.982, 0.991 and 0.981) and lower value of standard error of estimate (SEE = 6.30, 4.42 and 6.52), which suggested the multilayered adsorption of DF over the designed P-G-ILO nanohybrid and followed the pseudo second order kinetic model (PSO kinetic model) adsorption. The thermodynamic study reveals that adsorption was spontaneous and endothermic in nature and randomness onto the P-G-ILO nanohybrids surface increases after the DF adsorption. The mechanism of adsorption of DF demonstrated that the adsorption was mainly due to the electrostatic interaction, hydrogen bonding, and dipole interaction. P-G-ILO nanohybrid was reusable for up to five adsorption/desorption cycles.

Abrading-Induced Breakdown of Ag Nanoparticles into Atomically Dispersed Ag for Enhancing Antimicrobial Performance

Silver is among the most essential antimicrobial agents. Increasing the efficacy of silver-based antimicrobial materials will reduce operating costs. Herein, we show that mechanical abrading causes atomization of Ag nanoparticles (AgNPs) into atomically dispersed Ag (AgSAs) on the surfaces of an oxide-mineral support, which eventually boosts the antibacterial efficacy considerably. This approach is straightforward, scalable, and applicable to a wide range of oxide-mineral supports; additionally, it does not require any chemical additives and operates under ambient conditions. The obtained AgSAs-loaded γ-Al₂O₃ inactivated Escherichia coli (E. coli) five times as fast as the original AgNPs-loaded γ-Al₂O₃. It can be utilized over 10 runs with minimal efficiency loss. The structural characterizations indicate that AgSAs exhibit a nominal charge of 0 and are anchored at the doubly bridging OH on the γ-Al₂O₃ surfaces. Mechanism studies demonstrate that AgSAs, like AgNPs, damage bacterial cell wall integrity, but they release Ag⁺ and superoxide substantially faster. This work not only provides a simple method for manufacturing AgSAs-based materials but also shows that AgSAs have better antibacterial properties than the AgNPs counterpart.

Photocatalytic Performances and Antifouling Efficacies of Alternative Marine Coatings Derived from Polymer/Metal Oxides (WO3@TiO2)-Based Composites

This work concerns development of alternative antifouling paints for marine applications using composite metal oxides derived from TiO2 and WO3. Composite metal oxides with a variety of tungsten content were prepared via a sol–gel process using titanium isopropoxide and sodium tungstate dihydrate as the precursors. The crystalline phase, bandgap energy, morphology, surface structure, and electronic states of the synthesized products were then characterized and confirmed by XPS, XRD, UV/Vis spectroscopy, SEM-EDX, and TEM techniques. Photocatalytic performance polymer film loaded with composite metal oxides containing 10% by mole of WO3 (10%WO3@TiO2) was confirmed both under UV irradiation and in the dark. The results are discussed in light of oxygen vacancies and the presence of heterojunctions between the TiO2 and WO3 domains in the composites, which eventually lead to suppression of charges recombination. Finally, antifouling and the antimicrobial efficacy of the polymer film loaded with composite metal oxide particles (10%WO3@TiO2) were evaluated under static marine immersion conditions using Zobell Marine agar. After 30 days, the percentage fouling coverage (16.35%), colonies number (CFU value 12 × 103), and percentage reduction of colonies (92.94%), were obtained, which significantly outperformed those of the control (the bare substrate).

Collaborative Enhancement of Humidity Sensing Performance by KCl-Doped CuO/SnO2 p-n Heterostructures for Monitoring Human Activities

In this study, a high-performance humidity sensor based on KCl-doped CuO/SnO₂ p-n heterostructures was fabricated by a ball milling-roasting method. The morphology and nanostructure of the fabricated KCl-CuO/SnO₂ composite were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and nitrogen sorption analysis. The results showed that the humidity sensor had a high sensitivity of 194 kΩ/%RH, short response and recovery times of 1.0 and 1.5 s, a low hysteresis value, and good repeatability. The energy band structure and complex impedance spectrum of the KCl-CuO/SnO₂ composite indicated that the excellent humidity sensing performance originated from the ionic conductivity of KCl, the formation of heterojunctions, the change in the Schottky barrier height, and the depletion of electronic depletion layers. The KCl-CuO/SnO₂ sensor has great potential in respiratory monitoring, noncontact sensing of finger moisture, and environmental monitoring.

Novel imidazolium-thiohydantoin hybrids and their Mn(iii) complexes for antimicrobial and anti-liver cancer applications

We present the effective synthesis and structural characterization of three novel imidazolium-thiohydantoin ligands (IMTHs, 5a–c) and their Mn(iii) complexes (Mn(iii)IMTHs, 6a–c) in this study. The findings of elemental analyses, spectral analyses and magnetic measurements will be used to infer the stoichiometry, coordination styles, and geometrical aspects of Mn(iii)IMTHs. The new compounds were evaluated for their chemotherapeutic potential against ESKAPE pathogens and liver cancer (HepG2). According to the MIC and MBC values, the bactericidal and bacteriostatic activities of IMTHs have been significantly improved following coordination with the Mn(iii) ion. The MTT assay results showed that all Mn(iii)IMTHs had the potential to reduce the viability of liver carcinoma (HepG2) cells in a dose-dependent manner, with the BF₄-supported complex (6b) outperforming its counterparts (6a and 6c) as well as a clinical anticancer drug (VBL). Additionally, Mn-IMTH₂ (6b) showed the highest level of selectivity (SI = 32.05) for targeting malignant cells (HepG2) over healthy cells (HL7702).

We present the effective synthesis and structural characterization of three novel imidazolium-thiohydantoin ligands (IMTHs, 5a–c) and their Mn(iii) complexes (Mn(iii)IMTHs, 6a–c) in this study.

MOF-derived nanocrystalline ZnO with controlled orientation and photocatalytic activity

We show here that MOF-5, a sample Zn-based MOF, can uniquely transform into distinct zinc oxide nanostructures. Inspired by the interconversion synthesis of zeolites, we converted MOF-5 into nanocrystalline ZnO. We found the conversion of MOF-5 into ZnO to be tunable and straightforward simply by controlling the treatment temperature and choosing an appropriate structure-directing agent (SDA). Refined X-ray diffraction (XRD) patterns showed that a synthesis temperature of 180 °C (sample ZnO-180) was optimal for achieving high crystallinity. We examined ZnO-180 with high-resolution transmission electron microscopy (HRTEM), which confirmed that the samples were made of individual crystallites grown along the c-axis, or the (001) direction, thus exposing lower energy surfaces and corroborating the XRD pattern and the molecular dynamics calculations. Further investigations revealed that the obtained ZnO at 180 °C has a superior photocatalytic activity in degrading methylene blue to other ZnO nanostructures obtained at lower temperatures.