Norsuria Mahmed
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Preferred name
Norsuria Mahmed
Official Name
Norsuria, Mahmed
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Mahmed, Norsuria
Mahmed, N.
Norsuria, Mahmed
Norsuria, M.
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24802694300
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FOC-8505-2022

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Adsorption efficiency and photocatalytic activity of silver sulphide-activated carbon (Ag₂S-AC) composites

2025 , Siti Norsaffirah Zailan , Norsuria Mahmed , Aissa Bouaissi , Zahra Ramadlan Mubarokah , Mohd Natashah Norizan , Nurfina Yudasari , Ili Salwani Mohamad , Siti Salwa Mohammad Shirajuddin

Background: This study investigates the adsorption efficiency and photocatalytic activity of silver sulphide-activated carbon (Ag₂S-AC) composites derived from ground coffee waste (GCW). Methods: In this work, GCW was preceding to carbonized at 500 ± 2°C for hours and formed biochar. Then, GCW was subjected to activation using hydrochloric acid (HCl), phosphoric acid (H₃PO₄) and potassium hydroxide (KOH). The mixture was left to soak for 24 h at room temperature, followed by carbonization at 350 and 500˚C. In the meantime, the silver sulphide (Ag₂S) was synthesized by using an ion exchange method. Sodium sulphide (Na₂S) was used as sulphur source and mixed with silver nitrate (AgNO₃) and sodium citrate (NaCit) for two hours, then dried in oven at 50 ± 2°C for 10 h. Next, the carbonized AC was subsequently combined with synthesized silver sulphide, resulting in the creation of Ag₂S-activated carbon composites that functioned both as adsorbent and photocatalyst. Their capabilities as adsorbents and photocatalyst were studied by using copper ions (Cu2+) and methylene blue (MB) solution. Significance findings: Based on results, GCW and all the prepared activated carbons are in the amorphous phase, except for the Ag₂S-AC composites, where the Ag₂S peak reflection can be observed from the X-ray diffraction (XRD) pattern. GCW shows rough and dense surface morphology. The AC shows different pore sizes and structures depending on the chemical activators used, where AC-KOH shows the largest pore size (165.31 μm). The existence of micropores can be observed in all the activated carbon samples. For the adsorption of Cu2+, all samples show more than 99 % of the removal efficiency. While for photocatalytic testing, the Ag₂S-H₃PO₄ sample shows the highest degradation rate (97.7 %) of MB solutions.

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Ground coffee waste-derived activated carbon a sustainable adsorbent and photocatalyst for effective methylene blue dye degradation

2024-12 , Or Yang Jai Xien , Siti Norsaffirah Zailan , Norsuria Mahmed , Mohd Natashah Norizan , Ili Salwani Mohamad

This study focuses on harnessing the potential of ground coffee waste (GCW) as a valuable precursor to produce activated carbon (AC) through pyrolysis. The objective is to develop an eco-friendly adsorbent and photocatalyst for environmental remediation applications. Preceding pyrolysis at 350°C for 3.5 hours, GCW was subjected to activate using hydrochloric acid (HCl) and potassium hydroxide (KOH). The resulting AC was subsequently combined with titanium dioxide (TiO2) photocatalyst powder, resulting in the creation of TiO2-AC composites that functioned both as adsorbent and photocatalyst. The TiO2-AC composites were investigated for their adsorption and photocatalytic capabilities in the degradation of 10 ppm methylene blue dye under sunlight exposure for 240 minutes. Morphological analysis revealed a sponge-like structure for both HCl-activated AC and NaOH-activated AC, with HCl-AC exhibiting more pronounced and uniform pores compared to KOH-AC. Remarkably, GCW demonstrated the highest removal efficiency, effectively removing 97.34% of methylene blue, outperforming HCl-AC (16.89%) and KOH-AC (10.41%). Nonetheless, the AC-TiO2 composites, specifically HCl-AC/TiO2 and KOH-AC/TiO2, also exhibited considerable removal efficiencies of 93.31% and 92.46%, respectively. These findings underscore the promising potential of utilizing GCW-derived activated carbon as an environmentally sustainable solution for organic pollutant treatment and herald its significance in promoting greener approaches to waste utilization and environmental protection.

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Influence of ZnO Nanoparticles on Mechanical Properties and Photocatalytic Activity of Self-cleaning ZnO-Based Geopolymer Paste

2020-06-01 , Siti Norsaffirah Zailan , Bouaissi, Aissa , Norsuria Mahmed , Mohd. Mustafa Al Bakri Abdullah

Abstract: The influence of zinc oxide (ZnO) nanoparticles on the mechanical properties and photocatalytic degradation of methylene blue (MB) of ZnO-based geopolymer material was investigated under the illumination of ultraviolet (UV) radiations. In this work, ZnO-based geopolymer paste was manufactured using class F fly ash (FA) and ZnO nanoparticles powders with different mass percentages (0, 2.5, 5.0, 7.5 and 10 wt%). The FA-ZnO dry mix was activated by alkaline activator solution made from sodium silicate and sodium hydroxide with a ratio of 2.5. The mechanical properties were investigated by performing a compressive strength test at 28 days. The photocatalytic activity of ZnO nanoparticles was evaluated by measuring the photodegradation level of methylene blue under sunlight rays. The results showed a substantial influence of ZnO on the compressive strength, which decreased with the increase of ZnO amounts ranging from 2.5 to 7.5 wt% then a slightly increased at 10 wt% of ZnO. The addition of ZnO nanoparticles to a geopolymeric material showed a satisfactory efficiency of photocatalytic degradation of methylene blue after 150 min of exposure to sunlight. Phase analysis revealed that the addition of ZnO nanoparticles in the geopolymeric system develops a new ZnO crystalline phases. Graphic Abstract: [Figure not available: see fulltext.].

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Potential Applications of Geopolymer Cement-Based Composite as Self-Cleaning Coating: A Review

2022-02-01 , Siti Norsaffirah Zailan , Norsuria Mahmed , Mohd. Mustafa Al Bakri Abdullah , Shayfull Zamree Abd. Rahim , Dewi Suriyani Che Halin , Sandu A.V. , Vizureanu P. , Zarina Yahya

Nowadays, concepts of self-cleaning have received great attention in construction building materials. Self-cleaning with the presence of photocatalyst has been applied in building materials to overcome the problem of building surfaces becoming dirty after exposure for a long time in highly polluted areas. To date, the concept of green blending materials has led to the development of a new binding material for green materials, which is geopolymer with an addition of photocatalyst. This review focused on the development of conventional self-cleaning paste, including the method of preparation and the impact of adding photocatalyst on physical and mechanical properties. However, although self-cleaning has been widely applied in conventional cement paste, its applications in geopolymers are still in the early stages of development and require more research. Therefore, this paper also intended to review the current knowledge on properties of geopolymer cement-based composite and its potential to be applied as a self-cleaning coating.

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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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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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