Norsuria Mahmed
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Preferred name
Norsuria Mahmed
Official Name
Norsuria, Mahmed
Alternative Name
Mahmed, Norsuria
Mahmed, N.
Norsuria, Mahmed
Norsuria, M.
Main Affiliation
Scopus Author ID
24802694300
Researcher ID
FOC-8505-2022

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Charge recombination in zinc oxide-based dye-sensitized solar cell: a mini review

2021-12 , Kaiswariah Magiswaran , Mohd Natashah Norizan , Ili Salwani Mohamad , Norsuria Mahmed , Siti Norhafizah Idris , Sharizal Ahmad Sobri

Dye-sensitized solar cell (DSSC) has been studied widely due to its efficiency and the simplicity of manufacturing technology. Much research has been performed to improve the photovoltaic output parameters in DSSC by modifying the photoanode layers. The efforts to investigate DSSC mainly focus on how to increase light absorption, speed electron transport in circuits, and reduce charge recombination. This review discusses the process of charge recombination and the paths of occurrence in a DSSC. Recombination occurs when the electrons in the conduction band fall into the valance band holes and is considered an unnecessary process in DSSC. Due to the recombination process, the photocurrent and the photovoltage are reduced, leading to lower power conversion efficiency. Hence, the ways to overcome the charge recombination process were also discussed.

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Effect of graphene oxide on microstructure and optical properties of TiO2 thin film

2019-01-01 , Azani A. , Dewi Suriyani Che Halin , Razak K.A. , Mohd. Mustafa Al Bakri Abdullah , Mohd Salleh M.A.A. , Abdul Razak M.F.S. , Norsuria Mahmed , Ramli M.M. , Ayu Wazira Azhari , Chobpattana V.

GO/TiO2 thin films have been synthesized from titanium (IV) isopropoxide (TTIP) by a sol-gel method. The films were deposited onto a glass substrate using spin coating deposition technique then were subjected to annealed process at 350 °C. The different amount of graphene oxide (GO) was added into the parent solution of sol in order to investigate the microstructure, topography, optical band gap and photocatalytic activity of the thin films. The prepared thin films were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), UV-VIS spectrophotometry and degradation of methylene blue (MB). AFM images reveal a rougher surface of GO/TiO2 thin film than bare TiO2 thin film due to GO particles. Moreover, the SEM images showed the formation of semispherical microstructure of bare TiO2 changes to some larger combined molecules with GO addition. The UV-Vis spectrophotometer results show that with optical direct energy gap decreases from 3.30 to 3.18 eV after GO addition due to the effect of high surface roughness and bigger grain size. Furthermore, the optical results also indicated that GO improved the optical properties of TiO2 in the visible range region.

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Influence of carbonization conditions and temperature variations on the characteristics of coconut shell carbon

2024-03 , Yee Wen Yap , Nurul Najiha Abu Bakar , Norsuria Mahmed , Midhat Nabil Ahmad Salimi , Siti Norsaffirah Zailan , Azlin Fazlina Osman , Kamrosni Abdul Razak , Shayfull Zamree Abd. Rahim , Mohd Yusry Mohamad Yunus

This research aims to study the impact of carbonization atmospheres (ambient and nitrogen) and temperature on the properties of the coconut shell carbon (CSC) formed. To characterize the properties of CSC, the char yield percentage was calculated. Scanning Electron Microscopy (SEM) was used to study the surface morphology of CSC while X-ray Diffraction (XRD) analysis was done to identify the degree of graphitization. The carbon formed by carbonization under the nitrogen atmosphere yields lower char percentages compared to the ambient atmosphere. When the carbonization temperature elevated, both atmospheres produced a lower char yield percentage. This result is aligned with the SEM analysis where more and larger pores were observed from the carbon produced at higher temperatures and the result was further enhanced under a nitrogen atmosphere. It was found that the char yield of CSC decreased from 20.9% to 11.4% when the carbonization temperature increased from 400°C to 1000°C under the ambient atmosphere. More significant changes were formed through the carbonization process under the nitrogen atmosphere (from 18.3% to 6.03%). Pores formed when the volatile materials are released due to the elevated carbonization temperature, resulting in a reduction in total weight thus, the char yield percentage. From the XRD, all CSC produced from both atmospheres with varying temperatures poses an amorphous XRD pattern. However, the right shifted peak and the presence of an additional peak of ~40° suggest that under different temperatures and atmospheres, the crystallinity of the CSC produced was affected. This research provides insight for optimizing CSC production in the future to enhance the application of CSC.

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Near-Infrared (NIR) Silver Sulfide (Ag₂S) Semiconductor Photocatalyst Film for Degradation of Methylene Blue Solution

2023-01-01 , Mubarokah Z.R. , Norsuria Mahmed , Mohd Natashah Norizan , Ili Salwani Mohamad , Mohd. Mustafa Al Bakri Abdullah , Błoch K. , Nabiałek M. , Baltatu M.S. , Sandu A.V. , Vizureanu P.

A silver sulfide (Ag2S) semiconductor photocatalyst film has been successfully synthesized using a solution casting method. To produce the photocatalyst films, two types of Ag2S powder were used: a commercialized and synthesized powder. For the commercialized powder (CF/comAg2S), the Ag2S underwent a rarefaction process to reduce its crystallite size from 52 nm to 10 nm, followed by incorporation into microcrystalline cellulose using a solution casting method under the presence of an alkaline/urea solution. A similar process was applied to the synthesized Ag2S powder (CF/syntAg2S), resulting from the co-precipitation process of silver nitrate (AgNO3) and thiourea. The prepared photocatalyst films and their photocatalytic efficiency were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-visible spectroscopy (UV-Vis). The results showed that the incorporation of the Ag2S powder into the cellulose films could reduce the peak intensity of the oxygen-containing functional group, which indicated the formation of a composite film. The study of the crystal structure confirmed that all of the as-prepared samples featured a monoclinic acanthite Ag2S structure with space group P21/C. It was found that the degradation rate of the methylene blue dye reached 100% within 2 h under sunlight exposure when using CF/comAg2S and 98.6% for the CF/syntAg2S photocatalyst film, and only 48.1% for the bare Ag2S powder. For the non-exposure sunlight samples, the degradation rate of only 33–35% indicated the importance of the semiconductor near-infrared (NIR) Ag2S photocatalyst used.

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Thermal insulation properties of insulated concrete

2019-01-01 , Shahedan N.F. , Mohd. Mustafa Al Bakri Abdullah , Norsuria Mahmed , Kusbiantoro A. , Kamarudin Hussin , Sandu A.V. , Naveed A.

In building development, concrete is world most reliable, durable and versatile in construction materials. However, the heating and cooling system of the building is influenced by outside temperature due to extreme weather or areas condition leads to the consumption of a lot of electrical power. Thermally insulated concretes represent alternative construction materials to improve the thermal efficiency in building development. Various construction materials have different thermal insulation properties and thus, their suitability for various conditions vary. Thermal insulation properties are generally identified through specific heat, thermal conductivity, thermal diffusivity, thermal expansion, and mass loss. This paper present review the thermal insulation properties of variations insulated concrete are presently in growing demand of researchers to comfort and resolve prescribed issues related to insulated concrete in enhancing thermal insulation properties as a passive energy saving building.

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Magnetite (Fe₃O₄)-activated carbon composite from ground coffee waste for the removal of copper ions (Cu²⁺) from solution

2024-12 , Siti Norsaffirah Zailan , Norsuria Mahmed , Nur Mawaddah Juzaini , Mohd Natashah Norizan , Ili Salwani Mohamad , Aissa Bouaissi

The influence of the magnetite addition on the adsorption efficiency of activated carbon (AC) synthesized using different activators was investigated. In this work, the activated carbon from ground coffee waste (GCW) was prepared via activation with phosphoric acid (H3PO4) and potassium hydroxide (KOH), followed by carbonization at 500˚C. The magnetite (Fe₃O₄)-activated carbon composites were prepared by mixing the activated carbon with Fe₃O₄ powders. From the X-ray diffraction analysis, both activated carbons produced by H₃PO₄, and KOH are in the form of amorphous structures. Magnetite peaks can be observed from the magnetite-activated carbon composites. KOH-treated activated carbon shows the formation of porous honeycomb-like structures with large pore size (average diameter ±43 𝛍m) compared to H3PO4-treated activated carbon where the smaller, non-uniform pore morphology with the average diameter ±32 𝛍m was formed. The copper ions removal efficiency is the highest for biochar (almost 100%). For treated activated carbon, AC-KOH and MAC-KOH shows the highest adsorption removal efficiency (99.7%) compared to the acid-treated carbon (91.9%). Magnetite itself has good adsorption behaviour (93.6% efficiency) due to its nanocrystalline structure (high surface area) and functional groups.

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Near-Infrared (NIR) Silver Sulfide (Ag2S) semiconductor photocatalyst film for degradation of methylene blue solution

2023 , Zahrah Ramadlan Mubarokah , Norsuria Mahmed , Mohd Natashah Norizan , Ili Salwani Mohamad , Mohd. Mustafa Al Bakri Abdullah , Katarzyna Błoch , Marcin Nabiałek , Madalina Simona Baltatu , Andrei Victor Sandu , Petrica Vizureanu

A silver sulfide (Ag2S) semiconductor photocatalyst film has been successfully synthesized using a solution casting method. To produce the photocatalyst films, two types of Ag2S powder were used: a commercialized and synthesized powder. For the commercialized powder (CF/comAg2S), the Ag2S underwent a rarefaction process to reduce its crystallite size from 52 nm to 10 nm, followed by incorporation into microcrystalline cellulose using a solution casting method under the presence of an alkaline/urea solution. A similar process was applied to the synthesized Ag2S powder (CF/syntAg2S), resulting from the co-precipitation process of silver nitrate (AgNO3) and thiourea. The prepared photocatalyst films and their photocatalytic efficiency were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-visible spectroscopy (UV-Vis). The results showed that the incorporation of the Ag2S powder into the cellulose films could reduce the peak intensity of the oxygen-containing functional group, which indicated the formation of a composite film. The study of the crystal structure confirmed that all of the as-prepared samples featured a monoclinic acanthite Ag2S structure with space group P21/C. It was found that the degradation rate of the methylene blue dye reached 100% within 2 h under sunlight exposure when using CF/comAg2S and 98.6% for the CF/syntAg2S photocatalyst film, and only 48.1% for the bare Ag2S powder. For the non-exposure sunlight samples, the degradation rate of only 33–35% indicated the importance of the semiconductor near-infrared (NIR) Ag2S photocatalyst used.

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Synthesis methods of tin oxide as photoanode for dye-sensitized solar cell performance- a short review

2021-12 , Siti Norhafizah Idris , Mohd Natashah Norizan , Ili Salwani Mohamad , Norsuria Mahmed , Kaiswariah Magiswaran , Sharizal Ahmad Sobri

This review focused on the synthesis methods of tin oxide (SnO₂) nanoparticles as a photoanode for dye-sensitized solar cell (DSSC) and how it impacts the performance. There are many different techniques and various nanoparticles were produced and usually characterized by X-ray diffraction (XRD) to determine crystalline structure of SnO₂, scanning electron microscopy (SEM) to examine the surface morphology and size details and J-V solar simulator to verify current-voltage characteristics. In summary, considering all the methods reviewed, sol-gel is reported as the best method to produce SnO₂ nanoparticles for DSSC fabrication with the highest efficiency recorded of 3.96%.

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The effect of Spinacia )leracea dye absorption time on ZnO-based dye-sensitized solar cells’ electrical performance

2022-12 , Kaiswariah Magiswaran , Ili Salwani Mohamad , Norsuria Mahmed , Mohd Natashah Norizan , Siti Norhafizah Idris , Zuraida Abal Abas

Dye-sensitized solar cells (DSSC) have attracted much attention over the past 20 years due to their significance in energy conversion. However, the dye soaking time may significantly impact the efficacy of the photoanode semiconductor to carry the electronic charge to which the dye molecules adhere. An optimized dye soaking time may prevent the recombination of photo-excited electrons that are injected into the semiconductor of the DSSC. This study scrutinized the dependence of the zinc oxide (ZnO) photoanode soaking time of Spinacia oleracea (spinach) dye on the photocurrent-voltage characteristics. The ZnO film layer (photoanode) was prepared with commercial ZnO nanopowder and applied onto a fluorinedoped tin oxide (FTO) glass substrate using the doctor blade method. The prepared DSSCs’ were subjected to a variety of characterizations, including current density-voltage (J-V) characterization, UV-visible characterization, scanning electron microscope (SEM), and Xray diffraction (XRD). Comparing four variations of dye soaking time, ZnO-based DSSC photoanode soaked in the dye for an hour achieved an optimum efficiency of 0.03 %. This study proved that the efficiency of a DSSC can be improved by optimizing the dye soaking time.

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Thermal insulation and mechanical properties in the presence of glass bubble in fly ash geopolymer paste

2022-01-01 , Noor Fifinatasha Shahedan , Mohd. Mustafa Al Bakri Abdullah , Norsuria Mahmed , Liew Yun Ming , Shayfull Zamree Abd. Rahim , Ikmal Hakem Abdul Aziz , Kadir A.A. , Sandu A.V. , Mohd Fathullah Ghazli@Ghazali

The density, compressive strength, and thermal insulation properties of fly ash geopolymer paste are reported. Novel insulation material of glass bubble was used as a replacement of fly ash binder to significantly enhance the mechanical and thermal properties compared to the geopolymer paste. The results showed that the density and compressive strength of 50% glass bubble was 1.45 g/ cm3 and 42.5 MPa, respectively, meeting the standard requirement for structural concrete. Meanwhile, the compatibility of 50% glass bubbles tested showed that the thermal conductivity (0.898 W/mK), specific heat (2.141 MJ/m3K), and thermal diffusivity (0.572 mm2/s) in meeting the same requirement. The improvement of thermal insulation properties revealed the potential use of glass bubbles as an insulation material in construction material.

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