Incorporation Of ZnO Research Articles

Facile synthesis of ZnO/RGO/Fe2O3 using macroalgae Caulerpa taxifolia as green reductor and its application as malachite green removal

This study presents the synthesis of a novel ZnO/rGO/Fe₂O₃ composite using Caulerpa taxifolia as a green reductant for the effective removal of Malachite Green from aqueous solutions. Characterization techniques, including FTIR, SEM, and XRD, confirmed the successful incorporation of ZnO and Fe₂O₃ onto the rGO matrix, enhancing its adsorption properties. The composite achieved an exceptional maximum adsorption capacity of 454.5 mg/g at pH 9, significantly outperforming rGO alone and other adsorbents. The adsorption kinetics followed a pseudo-second-order model, indicating chemisorption as the dominant mechanism, with a high correlation coefficient (R² = 0.999). The adsorption isotherms were best described by the Langmuir model, suggesting monolayer adsorption. Thermodynamic parameters revealed that the process was spontaneous and exothermic, with a Gibbs free energy (ΔGo) of -10.93 kJ/mol at 25 °C. The composite's high adsorption capacity, rapid kinetics, and favorable thermodynamics highlight its potential as an efficient and sustainable adsorbent for dye removal. This research offers a promising approach to water treatment, aligning with environmentally friendly practices and providing a viable solution for mitigating water pollution caused by organic dyes. KEY WORDS: Reduced graphene oxide, Water treatment, Caulerpa taxifolia, Isothermal and kinetic studies, Malachite Green Bull. Chem. Soc. Ethiop. 2025, 39(1), 29-47. DOI: https://dx.doi.org/10.4314/bcse.v39i1.3

Experimental evaluation of the impact of ZnO on the radiation shielding ability of B2O3–PbO–ZnO–CaO glass systems

In this study, we used the melt quenching process to develop inexpensive, new radiation shielding glasses. The prepared glasses have a general formula 40B2O3–20PbO-(y)ZnO-(40-y)CaO, (y = 20, 25, 30 and 35 mol%). These glasses' gamma-radiation shielding properties were experimentally measured using Am-241, Co-60, and Cs-137 sources and a High-Purity Germanium (HPGe) detector, revealing that incorporation of ZnO had a positive impact of the density of these glasses. Moreover, the incorporation of ZnO enhanced the prepared glasses' attenuation performance. With greater energy the half value layer increased, and by a factor of 45 with a 0.059–1.333 MeV energy increase. For the four studied glasses the radiation protection efficiency (RPE) values are 100 % efficient at low energies (0.059 MeV), with a drastic decrease in the values across all four samples as the energy increases from 0.06 to 0.662 MeV.

Uranium extraction from wastewater by heteroatom-doped carbon microspheres derived from polyphosphazene loading with zinc oxide

The effective management of uranium-contaminated wastewater is crucial for environmental protection and public health safety. In this context, a novel composite was synthesized involving the intergration of zinc oxide into heteroatom-doped polyphosphazene carbon microspheres (TAC/ZnO) by hydrothermal method. The incorporation of ZnO into TAC significantly enhanced the porosity, offering more adsorption sites and improving the uranium adsorption performance. The optimal adsorption experiment achieved a remarkable adsorption capacity of 513.9 mg.g−1 for U(VI) at a pH of 5.5 within just 80 min. Additionally, the adsorption process was found to be endothermic and spontaneous, following both the Langmuir isothermal adsorption model and the pseudo-second-order kinetic model. Moreover, the TAC/ZnO presented higher selectivity for U(VI) in the presence of other cations. Even after 8 cycles, TAC/ZnO maintained a good removal rate for U(VI), decreasing from 97.54 % to 81.95 %. Furthermore, the findings from X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations indicated that the adsorption mechanism of U(VI) on TAC/ZnO may involve the coordinated interaction between oxygen atoms in Zn-O and nitrogen atoms in pyridinie-N-oxide with uranyl ions. Overall, this study presents an easily prepared, cost-effective, and highly efficient adsorbent that offers potential for large-scale production and practical application in purifying radioactive wastewater.

Charge transport properties and photostability of microcrystalline cellulose derived from Gigantochloa scortechinii-supported ZnO for enhanced acetaminophen degradation

A facile chemical mixing procedure was utilized to fabricate microcrystalline cellulose (MCC) derived from Gigantochloa scortechinii-supported ZnO photocatalysts, with different MCC content. The successful incorporation of ZnO onto the MCC surfaces was characterized by multitudinous characterization techniques. The photocatalytic evaluation studies were carried out under a very low UVC light intensity (9 W) against acetaminophen (ACE) in the aqueous solution. The MCC-supported ZnO (0.5:1) composites photocatalyst demonstrated a rapid and enhanced performance within 180 min under normal conditions, with a two-time higher value of rate constant k (1.12 ×10−2 min−1) as compared to pristine ZnO. The improved efficiency under UVC irradiation was associated with the excellent separation capability of photoexcited charge carriers, ease of electron migration, and electrons’ mediators by the MCC in the composite photocatalyst, as demonstrated by the band gap and photoluminescence analyses. The major reactive species were found to be hydroxyl radicals (•OH) and photoexcited holes (h+). The best photocatalyst has high photostability since it can be recycled up to five times towards ACE degradation without any regeneration step.

Gamma radiation’s influence on the tensile characteristics of waste animal fiber reinforced biocomposites

This study involves the preparation of polymer composites using untreated and treated chicken feather, leather, and cow hair fiber in combination with unsaturated polyester resin (UPR) and analyzing the effect of gamma radiation on tensile properties. These fibers were incorporated into the resin matrix at various weight percentages (2%, 5%, 7%, 10%, 12%, and 15%). Additionally, the nanoparticle ZnO was added in the composites as filler to improve the mechanical properties. The composites that utilized treated chicken feather fibers yielded superior results in comparison to those that relied on untreated fibers. Prepared composites outperformed neat composites when inorganic components were added as filler to UPR. Composite materials’ mechanical properties, particularly their tensile strength and modulus, can be improved by combining cow hair feather and chicken feather mixed fibers with ZnO filler and gamma radiation modification, according to this study. The morphological and spectroscopic analysis provides supporting evidence for the mechanical strength between the fibers and the resin. Ionizing gamma radiation modification of the fiber resulted in superior tensile characteristics. The optimized composites of animal fibers were then subjected to gamma radiation of variable dose of 0, 2.5, 5 and 7.5 kGy. The tensile properties were found to be the maximum at 5 kGy. Scanning electron microscopy was used to investigate the structural changes caused by the incorporation of animal fibers (chicken feather and cow hair) and ZnO. Composite material and UPR functional group identification were achieved by means of Fourier Transform Infrared Spectroscopy (FTIR).

Development of a multifunctional active food packaging membrane based on electrospun polyvinyl alcohol/chitosan for preservation of fruits

To mitigate environmental impacts in food preservation, the development of a multifunctional membrane for packaging is of importance. In this study, we have successfully fabricated a nanofibrous membrane using an eco-friendly electrospinning technique, comprising polyvinyl alcohol (PVA), chitosan (CS), and tannic acid (TA). The resulting nanofibrous membranes were crosslinked with glutaraldehyde (GA) and surface modified with ZnO. Our findings demonstrate that the crosslinking process enhances water resistance, reduces water vapor permeability, improves tensile strength (from 3 to 18 MPa), and enhances thermal stability (increasing decomposition temperature from 225 °C to 310 °C). Furthermore, the incorporation of TA and ZnO provides antioxidant properties to the membrane, effectively preventing food decomposition caused by UV-induced oxidation. Additionally, CS, TA, and ZnO synergistically exhibit a remarkable antibacterial effect with a bacteriostasis rate exceeding 99.9 %. The strawberry fresh-keeping experiment further confirms that our developed membrane significantly extends shelf life by up to 6 days. Moreover, cytotoxicity assays confirm the non-toxic nature of these membranes. The innovative significance of this study lies in proposing a robust GA-PVA/CS/TA@ZnO nanofibrous membrane with excellent mechanical properties, biocompatibility, and multiple functionalities including antibacterial, anti-ultraviolet, and anti-oxidation capabilities. It has tremendous potential for applications in active food packaging materials.

Regulating the metabolites through SiC, ZnO, and SnO2 nano-photocatalysts for elevating efficiency of photo fermentative bioH2 from Arundo donax L.

Photo-fermentation offers a promising roadmap for hydrogen production through their ability to harness light energy, however, its lower conversion efficiency is the major bottleneck for its realization. This study investigates the catalytic role of wideband gap nano-photocatalysts (SiC, ZnO, and SnO2) in enhancing hydrogen generation from Arundo donax L. Physio-optical characteristics of SiC, ZnO, and SnO2 nano-photocatalysts were assessed through SEM, XRD, and FT-IR which confirmed that incorporated nano-photocatalysts are spherical with uniform size distribution and there is no secondary phase. Hydrogen production experiments with varying nano-photocatalyst concentrations revealed that the maximum hydrogen yield of 104 and 98.83 mL/g was achieved with SiC and ZnO, respectively, at loading concentration of 200 mg/L, whereas 69.30 mL/g were observed with 100 mg/L of SnO2. The incorporation of SIC, ZnO, and SnO2 nano-photocatalyst permitted to increase the hydrogen content in overall gas production by 41 %, 37.34 %, and 18.26 % as compared to the control group. The increase in hydrogen production is related to the enhanced e-h pair separation lifetime of SiC, confirmed from PL spectroscopy. Addition of SiC caused a longer availability of electrons that helped to increase the metabolic rate by 38 % and 40.29 % in energy conversion efficiency (ECE). ANOVA results revealed significant differences between the control and maximum values of CHP, HC%, byproducts, and ECE. Tukey pairwise comparisons showed that SiC and ZnO had non-significant differences at 200 mg/L but both significantly outperformed SnO2 at 100 mg/L. Thus, the selection of suitable catalysts photocatalysts with enhanced e-h pair separation lifetime may offer promising prospects for sustainable energy technologies by enhancing biohydrogen production.

Multi-functional ceramic glazes with nano ZnO/Cu–ZnO incorporation

The study successfully enabled the creation of ceramic surfaces with multi functionalities, including superhydrophilicity, self-cleaning, antibacterial properties, and photocatalytic activity, by applying a glaze composition rich in nano ZnO/Cu–ZnO and utilizing surface chemistry and unique texturing on porcelain tiles. The tiles, coated with unique glaze compositions, were fired in an industrial furnace and heat treated. The crystalline phases and surface morphology of glazed surfaces were systematically evaluated using XRD, SEM, FT-IR, drop shape analyzer, and surface roughness profilometer. Key-factors affecting the wettability, self-clean ability, photocatalytic activity and antibacterial efficacy were discussed. Adding nano Cu into the glaze mixture that is rich in ZnO improves the evolution of zincite crystals, increases the specific surface energy, decreases surface roughness, provide superhydrophilicity and promotes the antibacterial effectiveness and photocatalytic activity. Superhydrophilic surfaces doped with nano Cu–ZnO display antibacterial characteristics that do not require UV or visible light. The quick achievement of complete self-cleaning, up to 100 %, is due to the presence of nano Cu particles in its structure. Hydrophilicity has the ability to improve the efficiency of photocatalysis. If a surface exhibits superhydrophilic properties, it shows exceptional photocatalytic performance. A surface that is solely photohydrophilic may not maintain self-cleaning. Hydrophilicity may be more important than photocatalysis in the self-cleaning effect.

Structural and optical studies of cost-effective ZnO/CCS nanocomposites

Traditionally, candle carbon soot (CCS) considered an undesired cause of air pollution, has been technologically utilized by new advanced techniques. Among carbon family, CCS is an environmentally friendly and cost-effective material. It has potential applications in various research areas such as gas sensors, solar cells and water/oil separation. In the present work, we have synthesized ZnO/CCS nanocomposite by the simple chemical method. This nanocomposite was characterized by X-ray diffraction (XRD), UV-Vis, FE-SEM/EDX, Raman and Photo luminance spectroscopy. It was found that CCS incorporation in ZnO effectively improved their structural, optical and photochemical properties. The incorporation of CCS within the ZnO accounts for the improved light-absorption capacity, extended light-response range and better photocatalytic activity. The reported CCS-ZnO composite has potential application as a photocatalyst.

Impact of incremental zinc-oxide incorporation on optical, magnetic, mechanical and photon transmission properties of K2O, SrF2, PbO containing borate-glasses

This study examines the radiation shielding properties of borate glass systems, with a focus on the simultaneous enhancement of optical, mechanical, and magnetic characteristics. The glass composition is represented by formula (55-x)B2O3+25PbO+10SrF2+10K2O + xZnO (where x: 0.0–10.0 mol%). By manipulating the ZnO concentration, we aimed to investigate its role as a radiation attenuator and its effects on the glass's optical, mechanical, and magnetic properties. Using traditional melt-quenching techniques, we produced the glass samples and examined their density, molar volume, linear attenuation coefficients (GLAC), mean free paths (GMFP), half-value layers (GHVL), and optical and magnetic properties. Our findings demonstrate that higher ZnO concentrations lead to a significant increase in density and a corresponding decrease in molar volume, thereby enhancing the glasses' ability to shield against gamma radiation. The radiation attenuation analysis revealed that increasing ZnO content substantially improves GLAC values across the energy range of 356–1333 keV. Additionally, ZnO incorporation decreases the optical bandgap, shifting the UV absorption edge to shorter wavelengths and enhancing UV dielectric capacity. Magnetic properties were assessed using vibrating sample magnetometer (VSM) measurements, showing a strong correlation between ZnO content and the effective atomic number (Zeff). It can be concluded that ZnO not only contributes to radiation shielding but also modifies the electronic structure of the glass, impacting its optical absorption properties.

Superabsorbent ZnO/rubber-based hydrogel composite for removal and photocatalytic degradation of methylene blue

A superabsorbent hydrogel was prepared by the free-radical copolymerization of natural rubber (NR) latex with poly(acrylic acid) (PAA) at NR loadings up to 50 wt%. An NR/PAA hydrogel containing 40 wt% of NR (NR-40) had a water absorption capacity of 214 g/g (21,400 %) of its dry weight. The compressive modulus increased 512 % and sample integrity was improved due to the physical entanglement of NR chains. NR-40 hydrogel removed 97 % of methylene blue (MB) from the aqueous solution in 1 h (at initial concentrations of 10–1000 mg/L) and produced a maximum removal of 1191 mg MB/g of hydrogel at an initial MB concentration of 4500 mg/L. The adsorption of MB was an endothermic process. Fourier transform infrared spectroscopy indicated that hydrogen bonding and electrostatic interaction drove the process. After the in-situ incorporation of ZnO into NR-40, absorbed energy from sunlight generated active species that could photocatalytically degrade adsorbed MB in the hydrogel matrix. The scavenger tests indicated that superoxide radical anions and hydroxyl radicals were the main species for this process. The hydrogel composite material showed good stability and could be regenerated and reused over 10 cycles, degrading >80 % of the adsorbed dye. This novel natural-based hydrogel provides double functions of adsorption and photodegradation of toxic dyes without the requirement of chemicals and a separation process.

Altering the optical, physical, and TL Dosimetric properties of MgSO4:Dy2O3:B2O3 transparent glass ceramic system: Evaluating the impact of roughness control and ZnO inclusion

This research examines the influence of surface roughness and the incorporation of ZnO (0.05–0.20 mol%) on the magnesium sulfate: dysprosium oxide: boron oxide (0.1 < x < 0.5) glass ceramic system for dosimeter applications. The parent glasses were prepared using the melt-quenching technique, with all samples melted at 1350 °C, except for B, which was melted at 700 °C. The crystallization, roughness, and optical properties were further determined using X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), and UV–Visible Spectrophotometry, respectively. The glass ceramics were exposed to 2.97 mGy of X-ray radiation ten cycles to assess specific dosimetric capabilities. Among the doped samples, MgSO4:Dy2O3-(0.2B2O3:0.05ZnO) exhibited the most promising performance as a dosimeter. Notably, the Thermoluminescence Dosimetry (TLD) readings of the pre- and post-polished 0.2MDB were 1041.96 nC and 1278.84 nC, respectively, with roughness values of 1.83 nm and 54.7 nm. Similarly, the TLD readings of the pre- and post-polished 0.05MDBZ were 1888.33 nC and 3262.63 nC, respectively, with roughness values of 17.3 nm and 19.8 nm. This work highlights that surface roughness significantly enhances trapping efficiency, underscoring the importance of dosimeter polishing as a beneficial step in enhancing their performance.

Influence of ZnO and Pr6O11 incorporation on the structural, thermal, optical, mechanical, and magnetic properties of calcium lithium borate glasses

A new glass of calcium lithium borate with the chemical formula (62.75-x)B2O3 + 20CaO + 0.25Pr6O11 + 17Li2O + xZnO, where x = 0, 2.5, 5, 10, 20 (mol%) have been prepared by conventional melt-quenching process. The amorphous character has been confirmed by the very short-range ordering structural matrices demonstrated through X-ray diffraction.The Raman spectra of the prepared glass revealed an enhancement of host lattice distortions. Differential scanning calorimetry (DSC) estimated the glass transition temperature (Tg), the onset temperature of crystallization (Tc), and the melting temperature (Tm). The glass transition decreased from 441 °C to 431 °C with increasing ZnO content up to 10 mol%. The criteria of glass samples up to 10 % ZnO have higher strength, rigidity and higher level of thermal stability. The physical quantities as density, molar volume, inter-atomic distance, polaron radius, packing density, and oxygen packing density were calculated. The glass density increases while the molar volume decreases with ZnO content. The optical properties of glasses were investigated using UV–Vis spectrophotometer. The addition of ZnO enhances the light absorption in UV–Vis. The results of the calculated direct and indirect optical band gaps decrease from 3.663 eV to 3.233 eV for and from 3.167 eV to 2.648 eV for direct and indirect transitions respectively with the increment of ZnO addition. Additionally, the dispersion energy and static refractive index clearly increase while the oscillator energy declines. The Makishima-Mackenzie’s (M−M) method was employed to ascertain mechanical parameters, including elastic moduli, and Poisson’s ratio. The study revealed an enhancement to the mechanical properties as the content of ZnO increased. Vibrating sample magnetometer (VSM) was used to investigate the magnetic properties of the prepared glass and all samples exhibited a ferromagnetic behavior. The incorporation of ZnO act as glass modifier controlling their physical, optical and mechanical properties making the investigated glasses suitable for various applications.

A Top-Down Approach to the Fabrication of Flame-Retardant Wood Aerogel with In Situ-Synthesized Borax and Zinc Borate.

In this study, a top-down approach was employed for the fabrication of flame-retardant wood aerogels. The process involved the removal of lignin and the removal of hemicellulose utilizing NaOH concomitantly with the incorporation of ZnO and urea. Subsequently, an in situ reaction with boric acid was conducted to prepare flame-retardant wood aerogels. The morphology, chemical composition, thermal stability, and flame retardancy of the samples were studied. The results show that the NaOH treatment transformed the wood into a layered structure, and flame-retardant particles were uniformly distributed on the surface of the aerogel. The peak heat release rate (PHRR) and total heat release (THR) of the flame-retardant aerogel were significantly reduced compared with the control samples. Meanwhile, its vertical burning test (UL-94) rating reached the V-0 level, and the Limiting Oxygen Index (LOI) could exceed 90%. The flame-retardant wood aerogel exhibited excellent flame retardancy and self-extinguishing properties.

Optimizing Synergistic Silica–Zinc Oxide Coating for Enhanced Flammability Resistance in Cotton Protective Clothing

This study reports process optimization studies of silica and zinc oxide-based flame-retardant (FR) coatings on cotton fabric for protective clothing and enhanced flammability properties. The experiments were designed by central composite design (CCD) using response surface methodology (RSM) to assess the synergistic protective effects of silica and zinc oxide FR coating. These prepared sols were coated on cotton fabrics by a simple dip dry cure process. The resulting FR-finished fabrics were characterized by SEM, mechanical properties, flame retardancy, and air permeability. SEM results confirmed the homogenous spreading of particles on cotton fabrics. From TGA results, it was noticed that the incorporation of silica and ZnO in the prepared nano-sols results in improved thermal stability of the FR-finished fabrics. These sol–gel-treated FR cotton fabrics showed excellent comfort properties, which shows their suitability for fire-retardant protective clothing. RSM analysis proved that the predicted values are in good agreement with the experimental values since R2 values for time to ignite, flame spread time, and air permeability were greater than 0.90. The optimized concentration of silica and ZnO in FR-finished fabrics was found to be 0.302% and 0.353%, respectively, which was further confirmed by confirmatory experiments. The optimization analysis successfully optimized the process for synergistic coating of silica and zinc oxide nanoparticles for enhanced flammability properties of FR cotton fabric for protective clothing.

Advancements in bifunctional catalysts for unitized regenerative fuel cells: exploring polaronic conduction and heterostructure designs

This study investigates the development and performance evaluation of a bifunctional catalyst tailored for unitized regenerative fuel cells (URFCs), capable of facilitating both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in fuel cell and electrolyzer modes. The primary challenge addressed is the creation of electrocatalysts exhibiting high activity and corrosion resistance for oxygen reduction and water oxidation at the oxygen electrode. A novel catalyst structure based on La0.5Sr0.5Fe0.5Ti0.5O3(LSFT), i.e. LSFT/ZnO/LSFT with a thickness of ∼2 μ m, is explored within an environmentally friendly medium. This catalyst demonstrates superior performance characteristics, including reduced overpotential in HER and enhanced stability during oxygen/hydrogen evolution processes in neutral medium. This study identifies the formation of interfacial polarons and polaronic charge modulation resulting from the incorporation of ZnO in LSFT, leading to multifunctional OER/HER behavior. Notably, the proposed interfacial small polaron mechanism offers valuable insights into complex interfacial phenomena and holds promise for applications in diverse heterostructures involving layered 2D materials and transition metal oxides. Moreover, the robust LSFT/ZnO/LSFT catalyst exhibits exceptional stability, maintaining for 168 h of oxygen evolution at a constant potential of approximately 1.66 V for a current density of 1 A cm−2 in a neutral medium. These findings mark a significant advancement in URFC technology and present promising avenues for clean energy storage solutions.

The effect of NaF and ZnO on regulating the network topological structure of CsPbBr3 quantum dots-embedded sodium borosilicate glass for energy-efficient dust indicator

All-inorganic CsPbX3 (X = Cl, Br, I) perovskite quantum dots (QDs) exhibit substantial potential in optoelectronics, rendering them valuable materials for next-generation lighting. However, the high cost and substantial usage of Cs present challenges. This study investigates the impact of NaF and/or ZnO modifiers on the network topological structure of CsPbBr3 QDs-embedded sodium borosilicate (SBS) glass. The incorporation of NaF and ZnO not only reduces Cs consumption and energy requirements during heat treatment but also enhances the stability and optical properties of CsPbBr3 QDs. Through a combination of experimental analysis and molecular dynamics (MD) simulations, we explore the changes in the SBS glass network topology induced by these modifiers. The results demonstrate that the addition of these modifiers effectively alters the topological structure of SBS glass, providing outstanding water and heat resistance for the embedded CsPbBr3 QDs. This suggests that the NaF and ZnO co-modified CsPbBr3 QDs-embedded SBS glass, with improved stability and optical characteristics, exhibits great promise for applications in optoelectronics.

Catalase‐functionalized ZnO and graphene oxide used as electrocatalyst for the selective detection of hydrogen peroxide

AbstractBACKGROUNDThis study focuses on the fabrication of a biosensor for the electrocatalytic and selective hydrogen peroxide (H2O2) recognition with bovine liver catalase (CAT) immobilized over a cysteine (c) modified zinc oxide nanoparticles/graphene oxide (c‐ZnO/GO) interface. The selectivity and sensitivity of the biosensor were augmented by the use of CAT and GO, respectively. The problem of CAT activity inhibition by GO was specifically solved by the incorporation of ZnO. Also, the cystine functionalization helped in better immobilization of CAT.RESULTSThis unique approach was first validated with in silico computations that calculated the binding affinities to study the interactions between different components of the biosensor. The electrochemical studies confirmed the step‐by‐step modification of the sensor, where along with GO, c‐ZnO nanoparticles also showed excellent electro‐conductivity by fundamentally improving the peak currents towards H2O2. The proposed bio‐nano interface exhibited superb electrocatalytic performance and specific detection capability for H2O2 across a broad linear range (0.1 to 40 μmol L−1), featuring a low detection limit (0.1 μmol L−1), as well as commendable reproducibility and storage durability. Furthermore, the biosensor yielded satisfactory outcomes for H2O2 detection in milk samples.CONCLUSIONSensing performance of nano‐bio interfaces can be augmented by using the appropriate nano‐composites and their efficacy confirmed through computational techniques such as molecular docking. The biosensor can be further repurposed into a wearable device by integration with lab‐on‐a‐chip platforms. © 2024 Society of Chemical Industry (SCI).

In Situ-Derived N-Doped ZnO from ZIF-8 for Enhanced Ethanol Sensing in ZnO/MEMS Devices.

Microelectromechanical systems (MEMS) gas sensors have numerous advantages such as compact size, low power consumption, ease of integration, etc., while encountering challenges in sensitivity and high resistance because of their low sintering temperature. This work utilizes the in situ growth of Zeolitic Imidazolate Framework-8 (ZIF-8) followed by its conversion to N-doped ZnO. The results obtained from scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicate that the in situ derivation of ZIF-8 facilitates the adhesion of ZnO particles, forming an island-like structure and significantly reducing the interfaces between these particles. Furthermore, powder X-ray diffraction (XRD) analysis, elemental mapping, and X-ray photoelectron spectroscopy (XPS) analysis confirm the conversion of ZIF-8 to ZnO, the successful incorporation of N atoms into the ZnO lattice, and the creation of more oxygen vacancies. The ZIF-8-derived N-doped ZnO/MEMS sensor (ZIF (3)-ZnO/MEMS) exhibits remarkable gas sensitivity for ethanol detection. At an operating temperature of 290 °C, it delivers a substantial response value of 80 towards 25 ppm ethanol, a 13-fold enhancement compared with pristine ZnO/MEMS sensors. The sensor also exhibits an ultra-low theoretical detection limit of 11.5 ppb to ethanol, showcasing its excellent selectivity. The enhanced performance is attributed to the incorporation of N-doped ZnO, which generates abundant oxygen vacancies on the sensor's surface, leading to enhanced interaction with ethanol molecules. Additionally, a substantial two-order-of-magnitude decrease in the resistance of the gas-sensitive film is observed. Overall, this study provides valuable insights into the design and fabrication strategies applicable to high-performance MEMS gas sensors in a broader range of gas sensing.

Aerosol metal-organic framework-derived Ni–Zn–Al hybrid catalyst for efficient methane Bi-reforming

Bi-reforming of methane (BRM) has emerged as a promising advancement in hydrogen production via direct carbon utilization. To promote BRM, metal-organic framework (MOF)-derived Ni–ZnO–Al2O3 hybrid catalyst was developed via aerosol-assisted approach. The results demonstrated that the incorporation of Al2O3 nanoparticle cluster and ZnO with Ni alloy enhanced the catalytic activity. Superior conversions of reactants and operation stability of the MOF-derived Ni–ZnO–Al2O3 hybrid catalyst was observed, and a high turnover frequency (TOFCH4) of 2.86 s−1 at a moderate operating temperature (650 °C) was achieved. Further, the H2/CO ratio of 1.4–6.5 was attained through the proper adjustment of feed ratios (H2O/CH4, CO2/CH4) and reaction temperature (600–700 °C). Overall, the newly fabricated MOF-derived Ni–ZnO–Al2O3 hybrid catalyst via aerosol-assisted method, demonstrated significant improvements in reducing the required operating temperature of BRM, which is beneficial for simultaneous reduction of the CO2 generated from the methane reforming plus energy consumption, and advancing the development of low-carbon H2 production.