Siti Khalijah Mahmad Rozi
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Siti Khalijah Mahmad Rozi
Official Name
Siti Khalijah, Mahmad Rozi
Alternative Name
Rozi, Siti Khalijah Mahmad
Rozi, S.K.M
Mahmad Rozi, S.K
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Scopus Author ID
57190815094

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  • Publication
    Amine functionalized carbon-based soybean curd residues (SCR) as potential adsorbent for carbon dioxide adsorption
    ( 2021-05-24)
    Zakaria D.S.
    ;
    Siti Khalijah Mahmad Rozi
    ;
    Hairul Nazirah Abdul Halim
    ;
    Mohamad S.
    Currently, carbon dioxide (CO2) capture can preserve environmental quality by using carbon- based adsorbent. In this research, Polyethylenehexamine (PEHA) functionalized carbon-based soybean curd residues (carbonized SCR-PEHA) was prepared for CO2 adsorption. Analysis of functional groups of the prepared adsorbent using Fourier Transform Infrared Spectroscopy (FTIR), confirmed the functionalization of PEHA on the carbonized SCR. CO2 uptake of the carbonized SCR-PEHA was compared with the bare SCR using Thermogravimetric Analyzer (TGA) analysis. TGA results revealed that the adsorption capacity of CO2 for carbonized SCR-PEHA and bare SCR are 8.816 mg/g and 3.027 mg/g respectively. It was observed that functionalization of the PEHA on the surface of carbonized SCR had improved the adsorption capacity of CO2 by 2.92 times as compared to bare SCR. The phenomenon can be explained from the interaction of the CO2 with the available amine sites provided for the carbonized SCR-PEHA which significantly improved the CO2 adsorption. Hence, the carbonized SCR-PEHA demonstrate potential adsorbent for CO2.
  • Publication
    An integrated DFT calculation and adsorption study of desiccated coconut waste-based biochar in CO2 environment
    ( 2024-01-01)
    Rafizah Rahamathullah
    ;
    Zakaria D.S.
    ;
    Siti Khalijah Mahmad Rozi
    ;
    Hairul Nazirah Abdul Halim
    ;
    Razak F.I.A.
    ;
    Sapari S.
    Abstract: This study presents a new series of amine-functionalized biochar derived from desiccated coconut waste (amine-biochar@DCW) as potential CO2 adsorbents. The CO2 adsorption experiment revealed that TETA-biochar@DCW had the highest adsorption capacity of 61.78 mg/g. Prior to the experimental studies, Density Functional Theory (DFT) was conducted at B3LYP/6-31G (d,p) to evaluate the energy band gap, global chemical reactivity descriptors (GCRD), and molecular electrostatic potentials (MEP) to compare the experimental findings. The results from the simulated data indicate that TETA-biochar@DCW has the lowest HOMO–LUMO gap at 2.7890 eV before adsorption, and it increases after CO2 adsorption occurs. The 3D plots from MEP also show that TETA-biochar@DCW is a reactive adsorbent for CO2 gases. Overall, the theoretical and experimental results of the amine-biochar@DCW suggest its potential as a promising and cost-effective adsorbent for CO2 capture. Highlights: • Newly prepared amine-biochar@DCW was assessed as CO2 adsorbents. • TETA-biochar@DCW presents the highest CO2 capture capacity. • TETA substituents significantly reduce the HOMO-LUMO gap values. • 3D MEP plots confirm the adsorption ability of TETA-biochar@DCW towards CO2 gases. Graphical Abstract: [Figure not available: see fulltext.]
  • Publication
    New porous amine-functionalized biochar-based desiccated coconut waste as efficient CO2 adsorbents
    ( 2024-03-01)
    Zakaria D.S.
    ;
    Siti Khalijah Mahmad Rozi
    ;
    Hairul Nazirah Abdul Halim
    ;
    Mohamad S.
    ;
    Zheng G.K.
    Climate change caused by the greenhouse gases CO2 remains a topic of global concern. To mitigate the excessive levels of anthrophonic CO2 in the atmosphere, CO2 capture methods have been developed and among these, adsorption is an especially promising method. This paper presents a series of amine functionalized biochar obtained from desiccated coconut waste (amine-biochar@DCW) for use as CO2 adsorbent. They are ethylenediamine-functionalized biochar@DCW (EDA-biochar@DCW), diethylenetriamine-functionalized biochar@DCW (DETA-biochar@DCW), triethylenetetramine-functionalized biochar@DCW (TETA-biochar@DCW), tetraethylenepentamine-functionalized biochar@DCW (TEPA-biochar@DCW), and pentaethylenehexamine-functionalized biochar@DCW (PEHA-biochar@DCW). The adsorbents were obtained through amine functionalization of biochar and they are characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, Brunauer–Emmett–Teller (BET), and thermogravimetric analysis (TGA). The CO2 adsorption study was conducted isothermally and using a thermogravimetric analyzer. From the results of the characterization analyses, a series of amine-biochar@DCW adsorbents had larger specific surface area in the range of 16.2 m2/g–37.1 m2/g as compare to surface area of pristine DCW (1.34 m2/g). Furthermore, the results showed an increase in C and N contents as well as the appearance of NH stretching, NH bending, CN stretching, and CN bending, suggesting the presence of amine on the surface of biochar@DCW. The CO2 adsorption experiment shows that among the amine modified biochar adsorbents, TETA-biochar@DCW has the highest CO2 adsorption capacity (61.78 mg/g) when using a mass ratio (m:m) of biochar@DCW:TETA (1:2). The adsorption kinetics on the TETA-biochar@DCW was best fitted by the pseudo-second model (R2 = 0.9998), suggesting the adsorption process occurs through chemisorption. Additionally, TETA-biochar@DCW was found to have high selectivity toward CO2 gas and good reusability even after five CO2 adsorption–desorption cycles. The results demonstrate the potential of novel CO2 adsorbents based on amine functionalized on desiccated coconut waste biochar. Graphical Abstract: (Figure presented.)
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