Banjuraizah Johar
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Preferred name
Banjuraizah Johar
Official Name
Banjuraizah, Johar
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Scopus Author ID
36782257500
Researcher ID
ELA-9787-2022

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  • Publication
    Impact of secondary phases content on the mechanical properties of cordierite
    ( 2017-01-01)
    Eing Kuan Kok
    ;
    Banjuraizah Johar
    ;
    Ho Li Ngee
    ;
    Zabar Yahidah
    The Cordierite ceramic body had been synthesized through conventional techniques solid state reaction by using non-stoichiometric composition (2.5 MgO. 1.8 Al2O3. 5 SiO2). The sintering temperature study was carried out by heat treated the samples at several degree of sintering temperature (1250 °C, 1275 °C, 1300 °C, 1325 °C, 1350 °C and 1375 °C). The qualitative and quantitative of crystalline phase analysis was accomplished by using X-ray Diffraction (XRD) technique and Rietveld structural refinement. The Scanning electron microscopy (SEM) was employed for morphology analysis. The mechanical properties of samples were determined by Vicker's Hardness test. Rietveld quantitative phase analysis results show that α phase Cordierite constitutes up to 96.4 wt% when the samples was sintered for 2 hours at sintering temperature of 1375 °C and obtained densified and orderly crystal structure arrangement in SEM micrograph except the mechanical strength. The sample obtained the uppermost α phase Cordierite content gained the lowest hardness values (4.0±0.8GPa). Conversely, the sample contains 90 wt% α-cordierite and 1.4 wt% magnesium titatnate achieve highest hardness which is about 4.9±0.79GPa.
  • Publication
    UVA-irradiated dual photoanodes and dual cathodes photocatalytic fuel cell: mechanisms and Reactive Red 120 degradation pathways
    ( 2022-11-01)
    Ong Y.P.
    ;
    Ho Li Ngee
    ;
    Ong S.A.
    ;
    Ibrahim A.H.
    ;
    Banjuraizah Johar
    ;
    Thor S.H.
    ;
    Lee S.L.
    ;
    Teoh T.P.
    To enhance dye removal and energy recovery efficiencies in single-pair electrode photocatalytic fuel cell (PFC-AC), dual cathodes PFC (PFC-ACC) and dual photoanodes PFC (PFC-AAC) were established. Results revealed that PFC-AAC yielded the highest decolorization rate (1.44 h−1) due to the promotion of active species such as superoxide radical (•O2−) and hydroxyl radical (•OH) when the number of photoanode was doubled. The results from scavenging test and UV-Vis spectrophotometry disclosed that •OH was the primary active species in dye degradation of PFC. Additionally, PFC-AAC also exhibited the highest power output (17.99 μW) but the experimental power output was much lower than the theoretical power output (28.24 μW) due to the strong competition of electron donors of doubled photoanodes to electron acceptors at the single cathode and its high internal resistance. Besides, it was found that the increments of dye volume and initial dye concentration decreased the decolorization rate but increased the power output due to the higher amount of sacrificial agents presented in PFC. Based on the abovementioned findings and the respective dye intermediate products identified from gas chromatography-mass spectrometry (GC-MS), the possible degradation pathway of RR120 was scrutinized and proposed.
  • Publication
    Formation of bio-based derived dicalcium silicate ceramics via mechanochemical treatment: physical, XRD, SEM and FTIR analyses
    ( 2023-07)
    Siti Nur Hazwani Yunus
    ;
    Khor Shing Fhan
    ;
    Banjuraizah Johar
    ;
    Nur Maizatul Shima Adzali
    ;
    Nur Hazlinda Jakfar
    ;
    Cheng Ee Meng
    ;
    Emma Ziezie Mohd Tarmizi
    ;
    Zainal Abidin Talib
    Beta-dicalcium silicate plays an important role in modern technology, but its tendency for polymorphic transformation results in the dusting phenomenon, is a major challenge. Therefore, mechanochemical treatment is used to reduce the particle size to retain the stability of the polymorph. In this study, pure dicalcium silicate ceramics of β-monoclinic structure with P 121/c1 space group were synthesized using calcium oxide and silicate powders derived from calcined eggshells and rice husks, respectively. The powders were mixed in a 2:1 molar ratio by mechanochemical treatment and heat-treated in the air at temperatures ranging from 900°C to 1100°C for 2 h. The results reveal that pure betadicalcium silicate formed at 1100°C without adding stabilizers. The properties of the pristine and sintered bodies were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). SEM revealed that the grain and pore sizes increase with rising sintering temperatures. FTIR spectra indicate the existence of Si-O bonds in -4 4 SiO tetrahedrons on all the samples. The sample sintered at 1000°C attains the lowest bulk density (1.2463 g/cm3), whereas the apparent porosity is the highest (62.5%). The reason for this trend is due to the decomposition of carbonate into CO2 gas. The densification onset for the sample sintered at 1100°C as the bulk density rises and grain size achieves 6.06 μm. This study further explains the effect of sintering temperatures on the physical, structural, and morphological properties of Ca2SiO4 which would also be useful for further optimization of its use.
  • Publication
    The Microstructural and Bioactivity Behavior of Magnesium Alloy Filled with Bioglass for Biomedical Application
    ( 2022-01-24)
    Nur Maizatul Shima Adzali
    ;
    Dahlan N.F.
    ;
    Banjuraizah Johar
    ;
    Baharom N.A.
    Magnesium alloy have known as degradable implant material due to biodegradable properties. However, by developed Mg alloy matrix composites containing a bioceramic will produced more biodegradable and does not need second surgical to remove the implants in body. Powder metallurgy route was used to fabricate the AZ91/BG composite by mixing, compacting and sintering. Mg alloy (AZ91) was reinforced with 0, 3, 6, and 9 wt% of bioglass (BG) before compact and sintered at 400°C for 2 hours. The Vickers hardness, scanning electron microscope, and x-ray diffraction are used to investigate the effect of BG particles addition on the mechanical properties and microstructure of the composite AZ91/BG. Bioactivity behaviour was studied by immersion test of AZ91/BG composite into phosphate buffered saline (PBS) solution for 72 hours. The results showed that as the addition of BG increases from 3 to 9 wt%, the hardness of AZ91/BG decrease from 43.3HV to 27.9HV. The result also showed the formation of protective layers or apatite layer on the surface of AZ91/BG composite after immersed in PBS solution for 72 hours. Phase analysis by XRD shows the presence of peak Ca10(OH)2(PO4)6 as the BG increased from 3 to 9 wt%. As a conclusion, AZ91/3BG shows the optimum composite for biomedical application based on its properties and bioactivity behaviour.
  • Publication
    Comparative study of different polyatomic ions of electrolytes on electricity generation and dye decolourization in photocatalytic fuel cell
    ( 2020-10-01)
    Ong Y.P.
    ;
    Ho Li Ngee
    ;
    Ong S.A.
    ;
    Banjuraizah Johar
    ;
    Ibrahim A.H.
    ;
    Lee S.L.
    ;
    Nordin N.
    Developing an effective interface interaction between photoanode and electrolyte is crucial for achieving superior photocatalytic fuel cell (PFC) performance. In this aspect, the contribution of the medium or electrolyte properties in the PFC system such as dye concentration, ionic nature and active radicals play a decisive role. Herein, we constructed a PFC with ZnO loaded nickel foam (ZnO/Ni) photoanode to study the influence of initial dye concentration, pH and supporting electrolytes of different polyatomic anions on the PFC performance. The optimum initial dye concentration and pH for the PFC with reactive red 120 as organic pollutants were found to be 30 mg L−1 and 7.5, respectively. The PFC performance can be synergistically enhanced by the addition of three types of polyatomic anions (Na3PO4, Na2SO4 and NaNO3) as supporting electrolytes. In turn, PO43- had the greatest influence on the reduction of internal resistance (highest short circuit current, Jsc) which corresponded to the conductivity of dye solution. Eventually, the higher charge of polyatomic ions could contribute to higher energy conversion efficiency in PFC. Nonetheless, SO42- anions favoured the cleavage of aromatic compounds by the advantage of recycling between SO42- and SO4[rad]- through hole scavenging activity. Comprehensively, our findings provided new insight into the selection of supporting electrolyte as well as the proposed mechanism of active radicals involved in PFC. Additionally, the ZnO/Ni photoanode demonstrated its excellent recyclability as it retained high PFC performance after five consecutive runs.
  • Publication
    The effect of pressing load on 8 mol% Yttria stabilized Zirconia grade 204NS-G
    (Trans Tech Publications Ltd., 2020-09)
    Tinesha Selvaraj
    ;
    Banjuraizah Johar
    ;
    Khor Shing Fhan
    The aim of this study is to understand the compaction characteristics of as received granulated 8 mol% yttria-stabilized zirconia (8YSZ). The samples were compacted at different loads and sintered at 1550 °C with the heating rate of 5°C/min for 5 hours. The densification, morphology analysis and crystal structure of the sintered were compared. The densification of granulated 8YSZ achieved 67% as increasing pressing load (0.1 tonne to 0.4 tonne). Rietveld quantitative phase analysis demonstrates that the tetragonal-ZrO2 phase reduces in granulated 8YSZ. The amount of cubic-ZrO2 phase dramatically dropped for both granulated as the pressing load increased. From the morphology analysis, granulated sample found to be porous observed on the surface as compaction load applied. Compaction load has no significant effect on the densification of granule sintered 8YSZ in the current study. The maximum densification was only reached 67% by using granulated 8YSZ powder with 0.4 tonne pressing load.
  • Publication
    The thermal behavior of cordierite-based ceramic with the substitution of treated flue gas desulfurization sludge in the non-stoichiometric cordierite composition
    (Springer, 2023)
    Fatin Fatini Othman
    ;
    Banjuraizah Johar
    ;
    Khor Shing Fhan
    ;
    Nik Akmar Rejab
    ;
    Suffi Irni Alias
    The substitution of FGD sludge that is rich with a glass-forming agent in non-stoichiometric cordierite composition is able to crystallize α-cordierite at the low sintering temperature, 1250 °C via solid-state reaction methods. Even though the substitution of MgO with FGD sludge can reduce the sintering temperature, the physical and mechanical properties of cordierite-based ceramic with FGD sludge are depleted due to the decomposition of SO3 took place during the sintering process and thus lead to the formation of voids in the ceramic. Thus, this paper is focusing on the thermal properties of cordierite-based ceramic when subjected to a high sintering temperature, 1000 °C using a dilatometric test. Different wt% of treated FGD sludge substitution gave a different type of CTE value, but 3.0 wt% of FGD sludge is able to obtain the lowest CTE value, 2.26 × 10–6/°C, compared to other samples as this sample obtains a single phase of α-cordierite phases.
  • Publication
    Influence of Flue Gas Desulfurization (FGD) waste as substitute feldspar on the physicomechanical porcelain properties
    (Springer, 2023-07)
    Suffi Irni Alias
    ;
    Banjuraizah Johar
    ;
    Syed Nuzul Fadzli Syed Adam
    ;
    Mustaffar Ali Azhar Taib
    ;
    Fatin Fatini Othman
    In this work, the influence of flue gas desulfurization (FGD) waste on the physical, mechanical and thermal properties of porcelain samples was investigated. The influence of the flue gas desulfurization (FGD) waste content (0–15 wt.%) which was sintered at a temperature of 1200 °C was also studied. The result showed that the substitution of feldspar by flue gas desulfurization (FGD) waste in porcelain bodies led to an increase in porosity resulted in a decrease in bulk density and mechanical strength when amount of FGD waste increased. Besides, the increasing FGD waste is also contributed to a decrease value in coefficient thermal expansion value which could reduce the thermal shock in porcelain. As a result, the sintered sample with the composition of 5 wt.% of FGD waste (S5) has the potential to be used as a porcelain tile as it meets the requirements of the standard tile (>35 MPa) despite flexural strength decreased. While the composition of 10 wt.% of FGD waste (S10) and 15 wt.% of FGD waste (S15) was found most suitable for developing porous brick because it meets the requirements of the porous brick standard (>2.5 MPa).
  • Publication
    The mechanochemical process and Hâ‚‚SOâ‚„ treatment on the rehydration of Anhydrite from FGD sludge into Gypsum and Hemihydrate
    (Springer, 2023)
    Fatin Fatini Othman
    ;
    Banjuraizah Johar
    ;
    Khor Shing Fhan
    ;
    Nik Akmar Rejab
    ;
    Suffi Irni Alias
    The rehydration of anhydrite (CaSO₄) leads to the crystallization of gypsum (CaSO₄⋅2H₂O) has been widely studied. Different process parameter had been conducted on anhydrite from the flue gas desulphurization (fgd) sludge to identify its ability to be reused as synthetic gypsum. A mechanochemical process using a high-energy planetary mill would break down the particle size and enhance the reaction of Ca²+ and SO₄ ²− with water while additives modify the number of ions present in the sample during the hydration. Difference hydrothermal temperatures (80 and 130 °C) for 30 min were conducted to dehydrate the synthetic gypsum from fgd sludge to hemihydrate (CaSO₄⋅0.5H₂O) to identify its potential to replace natural gypsum during the plaster of Paris production. The sample without a mechanochemical process wasn’t able to crystallize a high amount of gypsum while sample with 5 × 10–4 mol−1 of H₂SO₄ additive was able to crystallize a high amount of gypsum from the fgd sludge. After undergoing the hydrothermal process, all of the samples were able to crystallize hemihydrate at low-intensity peak due to the favourable of hemihydrate crystal’s growth at plane [31-3] only, which leads to the preferred orientation of hemihydrate crystal.
  • Publication
    A highly sustainable hydrothermal synthesized MnO2 as cathodic catalyst in solar photocatalytic fuel cell
    ( 2021-01-01)
    Ong Y.P.
    ;
    Ho Li Ngee
    ;
    Ong Soon An
    ;
    Banjuraizah Johar
    ;
    Ibrahim A.H.
    ;
    Thor S.H.
    ;
    Yap K.L.
    A unidirectional flow solar photocatalytic fuel cell (PFC) was successfully developed for the first time to offer alternative for electricity generation and simultaneous wastewater treatment. This study was focused on the synthesis of α-, δ- and β-MnO2 by wet chemical hydrothermal method for application as the cathodic catalyst in PFC. The crystallographic evolution was performed by varying the ratios of KMnO4 to MnSO4. The mechanism of the PFC with the MnO2/C as cathode was also discussed. Results showed that the catalytic activity of MnO2/C cathode was mainly predominated by their crystallographic structures which included Mn–O bond strength and tunnel size, following order of α- > δ- > β-MnO2/C. Interestingly, it was discovered that the specific surface areas (SBET) of different crystal phases did not give an impact on the PFC performance. However, the Pmax could be significantly influenced by the micropore surface area (Smicro) in the comparison among α-MnO2. Furthermore, the morphological transformation carried out by altering the hydrothermal duration demonstrated that the nanowire α-M3(24 h)/C with 1:1 ratio of KMnO4 and MnSO4 yielded excellent PFC performance with a Pmax of 2.8680 μW cm−2 and the lowest Rint of 700 Ω.
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