Ng Qi Hwa
Thumbnail Image
Preferred name
Ng Qi Hwa
Official Name
Ng, Qi Hwa
Alternative Name
Ng, Q. H.
Qi, Hwa Ng
Ng, Qi H.
Main Affiliation
Scopus Author ID
54413018300
Researcher ID
A-9192-2019

Research Output
Now showing 1 - 3 of 3
  • Publication
    Arthropods-mediated green synthesis of Zinc oxide nanoparticles using cellar spider extract a biocompatible remediation for environmental approach
    ( 2024-06)
    Muzamir Isa
    ;
    Muhammad Nur Aiman Uda
    ;
    M. A. R. Irfan
    ;
    Uda Hashim
    ;
    Subash Chandra Bose Gopinath
    ;
    Hafiza Shukor
    ;
    MRM Huzaifah
    ;
    Maimunah Mohd Ali
    ;
    Nur Hulwani Ibrahim
    ;
    Muaz Mohd Zaini Makhtar
    ;
    Ng Qi Hwa
    ;
    Mohd Khairul Rabani Hashim
    ;
    Zainal Abidin Arsat
    ;
    Nor Azizah Parmin
    ;
    Liyana Ahmad Sofri
    ;
    Mahfuz Affif Mohd Ruslan
    ;
    Tijjani Adam
    This study presents an eco-friendly approach to synthesizing zinc oxide nanoparticles (ZnO NPs) using extracts from cellar spiders, addressing environmental and health concerns associated with conventional methods. The spider extract efficiently reduced zinc acetate dihydrate, and the synthesized ZnO NPs underwent comprehensive quantitative characterization, including size, shape, morphology, surface chemistry, thermal stability, and optical properties using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), zeta potential measurements, thermogravimetric analysis (TGA), and UV-vis spectroscopy. The nanoparticles exhibited intended characteristics, and their adsorption capability for methylene blue (MB) was quantitatively assessed using the Freundlich isotherm model and pseudo-second-order kinetic model, providing numerical insights into MB removal efficiency. The study demonstrates the potential of these green-synthesized ZnO NPs for applications in environmental remediation, wastewater treatment, and antibacterial therapies, contributing to both sustainable nanomaterial development and quantitative understanding of their functional properties.
  • Publication
    Morphology and atomic configuration control of heavy metal attraction modified layer on screen-printed electrode to enhance electrochemical sensing performance
    (Elsevier B.V., 2023)
    Chyh Shyang Ong
    ;
    Nurul Hanisarina binti Zaharum
    ;
    Noorhashimah Mohamad Nor
    ;
    Abdul Latif Ahmad
    ;
    Ng Qi Hwa
    ;
    Khairunisak Abdul Razak
    ;
    Siew Chun Low
    The sensitivity of screen-printed electrochemical (SPE) sensors is heavily dependent on the selection of appropriate modifiers that can optimize the chemical (functional ligands, surface charge, binding energy) and physical (morphological structure) properties of the sensor surface. This study aimed to investigate the impact of these chemical and physical factors on the sensitivity of modified SPEs for the detection of lead and cadmium. The study employed anodic stripping voltammetry to evaluate the sensing performance of SPEs modified with different modifiers, including cellulose acetate, chitosan, Nafion, nylon-6, and silver nanoparticles. Results showed that metal-attracting functional groups and surface charged electrode were the dominant factors affecting the sensitivity of SPEs in heavy metal sensing. Specifically, negatively charged electrode surfaces and metal-attracting -SO32- ligands, as found in Nafion-modified SPE, were identified as the key factors in improving sensor selectivity, rather than the rough physical morphology of the SPE, which was believed to provide more metal detection sites. This conclusion was supported by the combination analyses of electrochemical impedance spectroscopy, electrochemically active surface area and computational molecular binding energy of bare and modified SPEs. The findings of this study provide valuable insights for selecting appropriate SPE modifiers and designing sensor architectures for heavy metal detection
  • Publication
    Study on the enhancement of colloidal stable poly(sodium 4‐styrene sulfonate) coated magnetite nanoparticles and regeneration capability for rapid magnetophoretic removal of organic dye
    (Society of Chemical Industry (SCI), 2020)
    Wai Hong Chong
    ;
    Ng Qi Hwa
    ;
    Jit Kang Lim
    ;
    Swee Pin Yeap
    ;
    Siew Chun Low
    BACKGROUND: A good colloidal stability of magnetite nanoparticles (MNPs) dispersion is of utmost importance for its environmentally related applications. In the present work, a water-soluble anionic polyelectrolyte, poly(sodium 4-styrene sulfonate) (PSS), was used to stabilize dispersions of MNPs in a pH-dependent aqueous medium. RESULTS: An excellent methylene blue (MB) dye removal efficiency at equilibrium of up to 94% has been observed by the colloidally stabilized nano-magnetites. Dynamic light scattering and electrophoretic analysis showed that the PSS-coated MNPs exhibited better colloidal stability, with an almost constant hydrodynamic diameter of ~150 nm and insignificant clustering behavior throughout the measuring time scale of 5 h. Transmission electron microscopy evidenced the success coating of PSS onto MNPs. In terms of its chemical resistance, the PSS-coated MNPs were able to tolerate a wide pH range from 2 to 10. This work depicts a simple physiochemical coating method to stabilize dispersions of nano-magnetites, which promoted a better MB adsorption capacity of PSS-coated MNPs at 14.9 mg g–1 than the naked MNPs at 10.38 mg g–1. The adsorption process follows Langmuir isotherm and pseudo-second-order reaction kinetics with both correlations R2 > 0.99. PSS-coated MNPs demonstrated outstanding regeneration capacity for four batch adsorption cycles with an almost consistent MB removal efficiency higher than 85%. CONCLUSION: This in-house developed nano-sorbent has potential in economical applications with a less budgeted adsorbent replacement (at least 4 cycles of regeneration) for low-cost separation of pollutants, such as MB from polluted water.
      1  1