Displaying publications 1 - 20 of 227 in total

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  1. AWANG R, SITI N.H.M. DAUD, CHI CY, MOHAMMAD HAFIZUDDIN HAJI JUMALI, ZALITA Z
    Sains Malaysiana, 2013;42:1663-1670.
    Filem nipis ZnO terdop Ga (ZnO:Ga) disediakan menggunakan teknik sol-gel dan salutan berputar. Ga didopkan kepada ZnO dengan peratusan berat (wt. %) yang berbeza iaitu 0, 2, 4, 6 dan 8 wt. %. Kesan pengedopan Ga ke atas struktur dan sifat optik filem nipis ZnO dikaji. Pencirian struktur filem nipis ini dilakukan menggunakan kaedah pembelauan sinar-X (XRD), mikroskop imbasan elektron pancaran medan (FESEM) dan mikroskop daya atom (AFM). Pencirian sifat optik filem nipis pula dilakukan menggunakan spektroskopi ultraungu cahaya nampak (UV-VIS) dan fotoluminesen (PL). Ujian XRD mengesahkan kesemua sampel berstruktur wurtzit. Saiz kristalit ZnO mengecil dengan peningkatan peratusan berat Ga seterusnya mengurangkan kekasaran permukaan filem. Pengedopan Ga menunjukkan peratus transmisi cahaya pada panjang gelombang 300 - 380 nm bertambah berbanding filem nipis ZnO tanpa dop. Nilai jurang tenaga optik, Eg dan keamatan PL filem nipis ZnO meningkat apabila pengedopan Ga dilakukan. Hasil kajian ini menunjukkan saiz kristalit yang lebih kecil memberi kesan ke atas sifat optik sampel pada peratus pengedopan Ga 0-6%. Pada peratus pengedopan Ga yang lebih tinggi, kesan transformasi struktur menjadi lebih dominan dalam mempengaruhi nilai Eg.
    Matched MeSH terms: Zinc Oxide
  2. Pang WY, Ahmad AL, Zaulkiflee ND
    J Environ Manage, 2019 Nov 01;249:109358.
    PMID: 31450197 DOI: 10.1016/j.jenvman.2019.109358
    The aim of this study is to evaluate the performance and antifouling properties of polyethersulfone (PES) membrane incorporated with dual nanofiller, zinc oxide (ZnO) and multi-walled carbon nanotube (MWCNT). The synergistic effect of the these nanofillers in PES membrane is studied by blending different ratio of ZnO/MWCNT nanofiller into the PES membrane. The fabricated membranes were characterized in terms of cross-section and surface morphology, surface hydrophilicity, pore size and porosity. The filtration performance of the membranes was tested using 50 mg/L humic acid (HA) solution as model solution. SEM image and gravimetric evaluation reported that the incorporation of both MWCNT and ZnO into the PES membrane improved porosity significantly up to 46.02%. Lower water contact angle of PES membrane incorporated with equal ratio of MWCNT and ZnO (PES 3) revealed that it has neat PES membrane properties and more hydrophilic membrane surface than single filler. PES 3 outperform other membranes with excellent HA permeate flux of 40.00 L/m2.h and rejection of 88.51%. Due to hydrophilic membrane surface, PES 3 membrane demonstrate efficient antifouling properties with lower relative flux reduction (RFR) and higher flux recovery ratio (FRR). PES 3 also showed notable antibacterial properties with less bacterial attached to the membrane compared to neat PES membrane (PES 0).
    Matched MeSH terms: Zinc Oxide*
  3. Mohamed Isa ED, Che Jusoh NW, Hazan R, Shameli K
    Environ Sci Pollut Res Int, 2021 Feb;28(5):5774-5785.
    PMID: 32975756 DOI: 10.1007/s11356-020-10939-1
    One of mankind's biggest concerns is water pollution. Textile industry emerged as one of the main contributors with dyes as the main pollutant. Presence of dyes in water is very dangerous due to their toxicity; thus, it is important to remove them from water. In these recent years, heterogeneous advance oxidation process surfaced as a possible dyes' removal technique. This process utilizes semiconductor as photocatalyst to degrade the dyes in presence of light and zinc oxide (ZnO) appears to be a promising photocatalyst for this process. In this study, pullulan, a biopolymer, was used to produce porous ZnO microflowers (ZnO-MFs) through green synthesis via precipitation method. The effects of pullulan's amount on the properties of ZnO-MFs were investigated. The ZnO-MF particle size decreased with the increased of pullulan amount. Interestingly, formation of pores occurred in presence of pullulan. The synthesized ZnO-MFs have the surface area ranging from 6.22 to 25.65 m2 g-1 and pore volume up to 0.1123 cm3 g-1. The ZnO-MF with the highest surface area was chosen for photocatalytic degradation of methyl orange (MO). The highest degradation occurred in 300 min with 150 mg catalyst dosage, 10 ppm initial dye concentration, and pH 7 experimental conditions. However, through comparison of photodegradation of MO with all synthesized ZnO-MFs, 25PZ exhibited the highest degradation rate. This shows that photocatalytic activity is not dependent on surface area alone. Based on these results, ZnO-MF has the potential to be applied in wastewater treatment. However, further improvement is needed to increase its photocatalytic activity.
    Matched MeSH terms: Zinc Oxide*
  4. Ayob MTM, Mohd HMK, Abdul Rahman I, Mohamed F, Hidzir NM, Radiman S
    Sains Malaysiana, 2016;45:1265-1273.
    Kami melaporkan hasil kajian terhadap nanokomposit Ag-ZnO dengan nisbah berat yang berbeza bagi Ag:ZnO (0:10,
    7:10 & 25:10) yang telah disediakan melalui kaedah sonokimia. Kajian fotomangkin terhadap nanokomposit Ag-ZnO
    menunjukkan peningkatan kecekapan fotomangkin terhadap foto-penguraian larutan akues metilena biru berbanding
    nanobahan ZnO tulen di bawah penyinaran cahaya nampak. Sampel Ag-ZnO pada nisbah 7:10 menunjukkan aktiviti
    fotomangkin terbaik dan mencapai kadar penguraian sehingga 94% bagi tempoh masa penguraian selama 80 min,
    diikuti 86% bagi sampel ZnO tulen dengan menggunakan kaedah yang sama. Morfologi, struktur bahan, sifat optik dan
    kehabluran bagi nanokomposit Ag-ZnO juga dibincangkan menerusi data yang diperoleh melalui mikroskop elektron
    transmisi, spektroskopi ultralembayung-cahaya nampak dan difraktometer analisis sinar-X. Hasil kajian menunjukkan
    bahawa dengan penambahan zarah Ag kepada ZnO telah meningkatkan kadar serapan cahaya bagi ZnO di kawasan
    cahaya nampak dan meningkatkan kadar pemisahan cas foto-aruhan bagi menghasilkan rawatan air tercemar pewarna
    yang lebih baik.
    Matched MeSH terms: Zinc Oxide
  5. Ahmad MB, Fatehi A, Zakaria A, Mahmud S, Mohammadi SA
    Int J Mol Sci, 2012;13(12):15640-52.
    PMID: 23443085 DOI: 10.3390/ijms131215640
    This study focuses on the fabrication and electrical characterization of a polymer composite based on nano-sized varistor powder. The polymer composite was fabricated by the melt-blending method. The developed nano-composite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FeSEM), and energy-dispersive X-ray spectroscopy (EDAX). The XRD pattern revealed the crystallinity of the composite. The XRD study also showed the presence of secondary phases due to the substitution of zinc by other cations, such as bismuth and manganese. The TEM picture of the sample revealed the distribution of the spherical, nano-sized, filler particles throughout the matrix, which were in the 10-50 nm range with an average of approximately 11 nm. The presence of a bismuth-rich phase and a ZnO matrix phase in the ZnO-based varistor powder was confirmed by FeSEM images and EDX spectra. From the current-voltage curves, the non-linear coefficient of the varistor polymer composite with 70 wt% of nano filler was 3.57, and its electrical resistivity after the onset point was 861 KΩ. The non-linear coefficient was 1.11 in the sample with 100 wt% polymer content. Thus, it was concluded that the composites established a better electrical non-linearity at higher filler amounts due to the nano-metric structure and closer particle linkages.
    Matched MeSH terms: Zinc Oxide/chemistry*
  6. Idris NJ, Bakar SA, Mohamed A, Muqoyyanah M, Othman MHD, Mamat MH, et al.
    Environ Sci Pollut Res Int, 2021 Feb;28(6):6966-6979.
    PMID: 33025441 DOI: 10.1007/s11356-020-10904-y
    In this work, sand/zinc oxide (ZnO)/titanium dioxide (TiO2)-based photocatalysts were hybridized with graphene oxide (GO) and GO_multi-walled carbon nanotubes (MWCNTs) hybrid solution. The novel hybrid was then used in photocatalysis to degrade dye contamination. The nanocomposite photocatalyst was initially fabricated by growing ZnO nanorods (NRs) via sol-gel immersion followed by synthesizing TiO2 NRs for different times (5 and 20 h) using a hydrothermal method on sand as a substrate. Prior to the hybridization, the initial GO was synthesized using electrochemical exfoliation and further mixed with 1 wt% MWCNTs to form GO_MWCNTs hybrid solution. The synthesized GO and GO_MWCNTs hybrid solution were then incorporated onto sand/ZnO/TiO2 nanocomposite-based photocatalysts through immersion. Various sand/ZnO/TiO2-based photocatalysts were then tested for methylene blue (MB) dye degradation within 3 days. On the basis of UV-Vis measurement, the highest MB degradation was achieved by using sand/ZnO NRs/TiO2 NRs (5 h)/GO_MWCNTs (92.60%). The high surface area and high electrical conductivity of GO_MWCNTs prolonged the lifetime of electron/hole separation and thus enhanced the photocatalytic performance.
    Matched MeSH terms: Zinc Oxide*
  7. Pillai P, Dharaskar S, Khalid M
    Chemosphere, 2021 Dec;284:131317.
    PMID: 34216929 DOI: 10.1016/j.chemosphere.2021.131317
    The current novel work presents the optimization of factors affecting defluoridation by Al doped ZnO nanoparticles using response surface methodology (RSM). Al doped ZnO nanoparticles were synthesized by the sol-gel method and validated by FTIR, XRD, TEM/EDS, TGA, BET, and particle size analysis. Moreover, a central composite design (CCD) was developed for the experimental study to know the interaction between Al doped ZnO adsorbent dosage, initial concentration of fluoride, and contact time on fluoride removal efficiency (response) and optimization of the process. Analysis of variance (ANOVA) was achieved to discover the importance of the individual and the effect of variables on the response. The model predicted that the response significantly correlated with the experimental response (R2 = 0.97). Among the factors, the effect of adsorbent dose and contact time was considered to have more influence on the response than the concentration. The optimized process parameters by RSM presented the adsorbent dosage: 0.005 g, initial concentration of fluoride: 1.5 g/L, and contact time: 5 min, respectively. Kinetic, isotherm, and thermodynamic studies were also investigated. The co-existing ions were also studied. These results demonstrated that Al doped ZnO could be a promising adsorbent for effective defluoridation for water.
    Matched MeSH terms: Zinc Oxide*
  8. Rajendran S, Hoang TKA, Trudeau ML, Jalil AA, Naushad M, Awual MR
    Environ Pollut, 2022 Jan 01;292(Pt B):118375.
    PMID: 34656681 DOI: 10.1016/j.envpol.2021.118375
    Recently, hetero junction materials (p-n-p and n-p-n) have been developed for uplifting the visible light activity to destroy the harmful pollutants in wastewater. This manuscript presents a vivid description of novel n-p-n junction materials namely CeO2-PPy-ZnO. This novel n-p-n junction was applied as the photocatalyst in drifting the mobility of charge carriers and hence obtaining the better photocatalytic activity when compared with p-n and pure system. Such catalyst's syntheses were successful via the copolymerization method. The structural, morphological and optical characterization techniques were applied to identify the physio-chemical properties of the prepared materials. Additionally, the superior performance of this n-p-n nanostructured material was demonstrated in the destruction of micro organic (chlorophenol) toxic wastes under visible light. The accomplished ability of the prepared catalysts (up to 92% degradation of chlorophenol after 180 min of irradiation) and their profound degradation mechanism was explained in detail.
    Matched MeSH terms: Zinc Oxide*
  9. Lam SM, Sin JC, Zeng H, Lin H, Li H, Mohamed AR, et al.
    Chemosphere, 2022 Jan;287(Pt 4):132384.
    PMID: 34597645 DOI: 10.1016/j.chemosphere.2021.132384
    BiFeO3 nanoparticle decorated on flower-like ZnO (BiFeO3/ZnO) was fabricated through a facile hydrothermal-reflux combined method. This material was utilized as a composite photocathode for the first time in microbial fuel cell (MFC) to reduce the copper ion (Cu2+) and power generation concomitantly. The resultant BiFeO3/ZnO-based MFC displayed distinct photoelectrocatalytic activities when different weight percentages (wt%) BiFeO3 were used. The 3 wt% BiFeO3/ZnO MFC achieved the maximum power density of 1.301 W m-2 in the catholyte contained 200 mg L-1 of Cu2+ and the power density was greatly higher than those pure ZnO and pure BiFeO3 photocathodes. Meanwhile, the MFC exhibited 90.7% removal of Cu2+ within 6 h under sunlight exposure at catholyte pH 4. The addition of BiFeO3 nanoparticles not only manifested outstanding capability in harvesting visible light, but also facilitated the formation of Z-scheme BiFeO3/ZnO heterojunction structure to induce the charge carrier transfer along with enhanced redox abilities for the cathodic reduction. The pronounced electrical output and Cu2+ reduction efficiencies can be realized through the synergistic cooperation between the bioanode and BiFeO3/ZnO photocathode in the MFC. Furthermore, the developed BiFeO3/ZnO composite presented a good stability and reusability of photoelectrocatalytic activity up to five cyclic runs.
    Matched MeSH terms: Zinc Oxide*
  10. Abdullah FH, Bakar NHHA, Bakar MA
    J Hazard Mater, 2022 Feb 15;424(Pt B):127416.
    PMID: 34655867 DOI: 10.1016/j.jhazmat.2021.127416
    Industrial wastewaters contain hazardous contaminants that pollute the environment and cause socioeconomic problems, thus demanding the employment of effective remediation procedures such as photocatalysis. Zinc oxide (ZnO) nanomaterials have emerged to be a promising photocatalyst for the removal of pollutants in wastewater owing to their excellent and attractive characteristics. The dynamic tunable features of ZnO allow a wide range of functionalization for enhanced photocatalytic efficiency. The current review summarizes the recent advances in the fabrication, modification, and industrial application of ZnO photocatalyst based on the analysis of the latest studies, including the following aspects: (1) overview on the properties, structures, and features of ZnO, (2) employment of dopants, heterojunction, and immobilization techniques for improved photodegradation performance, (3) applicability of suspended and immobilized photocatalytic systems, (4) application of ZnO hybrids for the removal of various types of hazardous pollutants from different wastewater sources in industries, and (5) potential of bio-inspired ZnO hybrid nanomaterials for photocatalytic applications using renewable and biodegradable resources for greener photocatalytic technologies. In addition, the knowledge gap in this field of work is also highlighted.
    Matched MeSH terms: Zinc Oxide*
  11. Hussein MZ, Azmin WH, Mustafa M, Yahaya AH
    J Inorg Biochem, 2009 Aug;103(8):1145-50.
    PMID: 19577306 DOI: 10.1016/j.jinorgbio.2009.05.016
    Currently the development of green chemistry approach with the use of biomaterial-based activities of microbial cells in the synthesis of various nanostructures has attracted a great attention. In this study, we report on the use of bacterium, Bacillus cereus as a biotemplating agent for the formation of zinc oxide nanoparticles with raspberry- and plate-like structures through a simple thermal decomposition of zinc acetate by maintaining the original pH of the reaction mixtures. Possible mechanism on the formation of the nanostructures is proposed based on the surface chemistry and biochemistry processes involved organic-inorganic interactions between zinc oxide and the microbial cells.
    Matched MeSH terms: Zinc Oxide/metabolism*; Zinc Oxide/chemistry
  12. Tripathy A, Pramanik S, Cho J, Santhosh J, Osman NA
    Sensors (Basel), 2014;14(9):16343-422.
    PMID: 25256110 DOI: 10.3390/s140916343
    The humidity sensing characteristics of different sensing materials are important properties in order to monitor different products or events in a wide range of industrial sectors, research and development laboratories as well as daily life. The primary aim of this study is to compare the sensing characteristics, including impedance or resistance, capacitance, hysteresis, recovery and response times, and stability with respect to relative humidity, frequency, and temperature, of different materials. Various materials, including ceramics, semiconductors, and polymers, used for sensing relative humidity have been reviewed. Correlations of the different electrical characteristics of different doped sensor materials as the most unique feature of a material have been noted. The electrical properties of different sensor materials are found to change significantly with the morphological changes, doping concentration of different materials and film thickness of the substrate. Various applications and scopes are pointed out in the review article. We extensively reviewed almost all main kinds of relative humidity sensors and how their electrical characteristics vary with different doping concentrations, film thickness and basic sensing materials. Based on statistical tests, the zinc oxide-based sensing material is best for humidity sensor design since it shows extremely low hysteresis loss, minimum response and recovery times and excellent stability.
    Matched MeSH terms: Zinc Oxide/chemistry*
  13. Saw KG, Tneh SS, Yam FK, Ng SS, Hassan Z
    PLoS One, 2014;9(2):e89348.
    PMID: 24586707 DOI: 10.1371/journal.pone.0089348
    The concentration of acceptor carriers, depletion width, magnitude of donor level movement as well as the sensitivity factor are determined from the UV response of a heterojunction consisting of ZnO on type IIb diamond. From the comparison of the I-V measurements in dark condition and under UV illumination we show that the acceptor concentration (∼10(17) cm(-3)) can be estimated from p-n junction properties. The depletion width of the heterojunction is calculated and is shown to extend farther into the ZnO region in dark condition. Under UV illumination, the depletion width shrinks but penetrates both materials equally. The ultraviolet illumination causes the donor level to move closer to the conduction band by about 50 meV suggesting that band bending is reduced to allow more electrons to flow from the intrinsically n-type ZnO. The sensitivity factor of the device calculated from the change of threshold voltages, the ratio of dark and photocurrents and identity factor is consistent with experimental data.
    Matched MeSH terms: Zinc Oxide/chemistry*
  14. Saw KG, Aznan NM, Yam FK, Ng SS, Pung SY
    PLoS One, 2015;10(10):e0141180.
    PMID: 26517364 DOI: 10.1371/journal.pone.0141180
    The Burstein-Moss shift and band gap narrowing of sputtered indium-doped zinc oxide (IZO) thin films are investigated as a function of carrier concentrations. The optical band gap shifts below the carrier concentration of 5.61 × 1019 cm-3 are well-described by the Burstein-Moss model. For carrier concentrations higher than 8.71 × 1019 cm-3 the shift decreases, indicating that band gap narrowing mechanisms are increasingly significant and are competing with the Burstein-Moss effect. The incorporation of In causes the resistivity to decrease three orders of magnitude. As the mean-free path of carriers is less than the crystallite size, the resistivity is probably affected by ionized impurities as well as defect scattering mechanisms, but not grain boundary scattering. The c lattice constant as well as film stress is observed to increase in stages with increasing carrier concentration. The asymmetric XPS Zn 2p3/2 peak in the film with the highest carrier concentration of 7.02 × 1020 cm-3 suggests the presence of stacking defects in the ZnO lattice. The Raman peak at 274 cm-1 is attributed to lattice defects introduced by In dopants.
    Matched MeSH terms: Zinc Oxide/chemistry*
  15. Haarindraprasad R, Hashim U, Gopinath SC, Kashif M, Veeradasan P, Balakrishnan SR, et al.
    PLoS One, 2015;10(7):e0132755.
    PMID: 26167853 DOI: 10.1371/journal.pone.0132755
    The performance of sensing surfaces highly relies on nanostructures to enhance their sensitivity and specificity. Herein, nanostructured zinc oxide (ZnO) thin films of various thicknesses were coated on glass and p-type silicon substrates using a sol-gel spin-coating technique. The deposited films were characterized for morphological, structural, and optoelectronic properties by high-resolution measurements. X-ray diffraction analyses revealed that the deposited films have a c-axis orientation and display peaks that refer to ZnO, which exhibits a hexagonal structure with a preferable plane orientation (002). The thicknesses of ZnO thin films prepared using 1, 3, 5, and 7 cycles were measured to be 40, 60, 100, and 200 nm, respectively. The increment in grain size of the thin film from 21 to 52 nm was noticed, when its thickness was increased from 40 to 200 nm, whereas the band gap value decreased from 3.282 to 3.268 eV. Band gap value of ZnO thin film with thickness of 200 nm at pH ranging from 2 to 10 reduces from 3.263eV to 3.200 eV. Furthermore, to evaluate the transducing capacity of the ZnO nanostructure, the refractive index, optoelectric constant, and bulk modulus were analyzed and correlated. The highest thickness (200 nm) of ZnO film, embedded with an interdigitated electrode that behaves as a pH-sensing electrode, could sense pH variations in the range of 2-10. It showed a highly sensitive response of 444 μAmM-1cm-2 with a linear regression of R2 =0.9304. The measured sensitivity of the developed device for pH per unit is 3.72μA/pH.
    Matched MeSH terms: Zinc Oxide/chemistry*
  16. Adil M, Lee K, Mohd Zaid H, A Shukur MF, Manaka T
    PLoS One, 2020;15(12):e0244738.
    PMID: 33382855 DOI: 10.1371/journal.pone.0244738
    Utilization of metal-oxide nanoparticles (NPs) in enhanced oil recovery (EOR) has generated substantial recent research interest in this area. Among these NPs, zinc oxide nanoparticles (ZnO-NPs) have demonstrated promising results in improving oil recovery due to their prominent thermal properties. These nanoparticles can also be polarized by electromagnetic (EM) field, which offers a unique Nano-EOR approach called EM-assisted Nano-EOR. However, the impact of NPs concentrations on oil recovery mechanism under EM field has not been well established. For this purpose, ZnO nanofluids (ZnO-NFs) of two different particle sizes (55.7 and 117.1 nm) were formed by dispersing NPs between 0.01 wt.% to 0.1 wt.% in a basefluid of sodium dodecylbenzenesulfonate (SDBS) and NaCl to study their effect on oil recovery mechanism under the electromagnetic field. This mechanism involved parameters, including mobility ratio, interfacial tension (IFT) and wettability. The displacement tests were conducted in water-wet sandpacks at 95˚C, by employing crude oil from Tapis. Three tertiary recovery scenarios have been performed, including (i) SDBS surfactant flooding as a reference, (ii) ZnO-NFs flooding, and (iii) EM-assisted ZnO-NFs flooding. Compare with incremental oil recovery from surfactant flooding (2.1% original oil in place/OOIP), nanofluid flooding reaches up to 10.2% of OOIP at optimal 0.1 wt.% ZnO (55.7 nm). Meanwhile, EM-assisted nanofluid flooding at 0.1 wt.% ZnO provides a maximum oil recovery of 10.39% and 13.08% of OOIP under EM frequency of 18.8 and 167 MHz, respectively. By assessing the IFT/contact angle and mobility ratio, the optimal NPs concentration to achieve a favorable ER effect and interfacial disturbance is determined, correlated to smaller hydrodynamic-sized nanoparticles that cause strong electrostatic repulsion between particles.
    Matched MeSH terms: Zinc Oxide*
  17. Mohd Yusof H, Mohamad R, Zaidan UH, Rahman NA
    Microb Cell Fact, 2020 Jan 15;19(1):10.
    PMID: 31941498 DOI: 10.1186/s12934-020-1279-6
    BACKGROUND: The use of microorganisms in the biosynthesis of zinc oxide nanoparticles (ZnO NPs) has recently emerged as an alternative to chemical and physical methods due to its low-cost and eco-friendly method. Several lactic acid bacteria (LAB) have developed mechanisms in tolerating Zn2+ through prevention against their toxicity and the production of ZnO NPs. The LAB's main resistance mechanism to Zn2+ is highly depended on the microorganisms' ability to interact with Zn2+ either through biosorption or bioaccumulation processes. Besides the inadequate studies conducted on biosynthesis with the use of zinc-tolerant probiotics, the understanding regarding the mechanism involved in this process is not clear. Therefore, this study determines the features of probiotic LAB strain TA4 related to its resistance to Zn2+. It also attempts to illustrate its potential in creating a sustainable microbial cell nanofactory of ZnO NPs.

    RESULTS: A zinc-tolerant probiotic strain TA4, which was isolated from local fermented food, was selected based on the principal component analysis (PCA) with the highest score of probiotic attributes. Based on the 16S rRNA gene analysis, this strain was identified as Lactobacillus plantarum strain TA4, indicating its high resistance to Zn2+ at a maximum tolerable concentration (MTC) value of 500 mM and its capability of producing ZnO NPs. The UV-visible spectroscopy analysis proved the formations of ZnO NPs through the notable absorption peak at 380 nm. It was also found from the dynamic light scattering (DLS) analysis that the Z-average particle size amounted to 124.2 nm with monodisperse ZnO NPs. Studies on scanning electron microscope (SEM), energy-dispersive X-ray (EDX) spectroscopy, and Fourier-transform infrared spectroscopy (FT-IR) revealed that the main mechanisms in ZnO NPs biosynthesis were facilitated by the Zn2+ biosorption ability through the functional groups present on the cell surface of strain TA4.

    CONCLUSIONS: The strong ability of zinc-tolerant probiotic of L. plantarum strain TA4 to tolerate high Zn2+ concentration and to produce ZnO NPs highlights the unique properties of these bacteria as a natural microbial cell nanofactory for a more sustainable and eco-friendly practice of ZnO NPs biosynthesis.

    Matched MeSH terms: Zinc Oxide*
  18. Abdullah FH, Abu Bakar NHH, Abu Bakar M
    J Hazard Mater, 2021 03 15;406:124779.
    PMID: 33338763 DOI: 10.1016/j.jhazmat.2020.124779
    Zinc oxide (ZnO) photocatalysts were successfully synthesized via chemical and green, environmentally-benign methods. The work highlights the valorization of banana peel (BP) waste extract as the reducing and capping agents to produce pure, low temperature, highly crystalline, and effective ZnO nanoparticles with superior photocatalytic activities for the removal of hazardous Basic Blue 9 (BB9), crystal violet (CV), and cresol red (CR) dyes in comparison to chemically synthesized ZnO. Their formation and morphologies were verified by various optical spectroscopic and electron microscopic techniques. XRD results revealed that the biosynthesized ZnO exhibited 15.3 nm crystallite size when determined by Scherrer equation, which was smaller than the chemically synthesized ZnO. The FTIR spectra confirmed the presence of biomolecules in the green-mediated catalyst. EDX and XPS analyses verified the purity and chemical composition of ZnO. Nitrogen sorption analysis affirmed the high surface area of bio-inspired ZnO. Maximum removal efficiencies were achieved with 30 mg green ZnO catalyst, 2.0 × 10-5 M BB9 solution, alkaline pH 12, and irradiation time 90 min. Green-mediated ZnO showed superior photodegradation efficiency and reusability than chemically synthesized ZnO. Therefore, this economical, environment-friendly photocatalyst is applicable for the removal of organic contaminants in wastewater treatment under visible light irradiation.
    Matched MeSH terms: Zinc Oxide*
  19. Yashni G, Al-Gheethi A, Radin Mohamed RMS, Dai-Viet NV, Al-Kahtani AA, Al-Sahari M, et al.
    Chemosphere, 2021 Oct;281:130661.
    PMID: 34029959 DOI: 10.1016/j.chemosphere.2021.130661
    Textile industry is one of the most environmental unfriendly industrial processes due to the massive generation of colored wastewater contaminated with dyes and other chemical auxiliaries. These contaminants are known to have undesirable consequences to ecosystem. The present study investigated the best operating parameters for the removal of congo red (CR, as the model for dye wastewater) by orange peels extract biosynthesized zinc oxide nanoparticles (ZnO NPs) via photocatalysis in an aqueous solution. The response surface methodology (RSM) with ZnO NPs loadings (0.05-0.20 g), pH (3.00-11.00), and initial CR concentration (5-20 ppm) were used for the optimization process. The applicability of ZnO NPs in the dye wastewater treatment was evaluated based on the techno-economic analysis (TEA). ZnO NPs exhibited hexagonal wurtzite structure with = C-H, C-O, -C-O-C, CC, O-H as the main functional groups. The maximum degradation of CR was more than 96% with 0.171 g of ZnO NPs, at pH 6.43 and 5 ppm of CR and 90% of the R2 coefficient. The specific cost of ZnO NPs production is USD 20.25 per kg. These findings indicated that the biosynthesized ZnO NPs with orange peels extract provides alternative method for treating dye wastewater.
    Matched MeSH terms: Zinc Oxide*
  20. Harun NH, Mydin RBSMN, Sreekantan S, Saharuddin KA, Seeni A
    J Biomater Sci Polym Ed, 2021 07;32(10):1301-1311.
    PMID: 33849408 DOI: 10.1080/09205063.2021.1916866
    An innovative nano-base polymer that scavenges radicals and reactive oxygen species exhibits potential antibacterial properties, which are crucial in the biomedical field, particularly in reducing nosocomial infections. However, the safety of this nano-based polymer, which has direct contact with the human system, has not been fully understood. The present study investigated the cytocompatibility and hemocompatibility responses of linear low-density polyethylene polymer (LLDPE) embedded with difference ratios of heterogeneous TiO2/ZnO nanocomposites. Exposure of the blood and fibroblast cells to LLDPE/100Z and LLDPE/25T75Z/10% nanocomposite films for 48 and 72 h decreased their viability by less than 40%, compared with LLDPE, LLDPE/100T and LLDPE/25T75Z/5% nanocomposite films. It also presented possible cellular damage and cytotoxicity, which was supported by the findings from the significant release of extracellular lactate dehydrogenase profiles and cell survival assay Further observation using an electron microscope revealed that LLDPE films with heterogeneous 25T75Z/5% promoted cell adhesion. Moreover, no hemolysis was detected in all ratios of heterogeneous TiO2/ZnO nanocomposite in LLDPE film as it was less than 0.2%, suggesting that these materials were hemocompatible. This study on LLDPE film with heterogeneous TiO2/ZnO nanocomposites demonstrated favorable biocompatible properties that were significant for advanced biomedical polymer application in a hospital setting.
    Matched MeSH terms: Zinc Oxide*
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