Now showing 1 - 10 of 21
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The study and preparation of polyaniline-graphene oxide as robust counter electrode for dye-sensitized solar cells

2022-05-18 , Mohd Fairul Sharin Abdul Razak , Shukor A.A. , Mohd Nazry Salleh , Nawawi W.I. , Norhayati Sabani , Badri A.

The study of alternative materials and platinum-free counter electrodes (CE) for the development of dye- sensitized solar cells (DSSC) has been highlighted nowadays. Polyaniline (PANI) is one of the most common conducting polymers applied in electrochemical energy storage and conversion technologies such as supercapacitors, rechargeable batteries and fuel cells. However, PANI counter electrodes lack long-term stability due to their low surface area and large volume changes during the release of ions. In that regard, this research work focused on the modification of protonated PANI with graphene oxide (GO) at various weight percentages (wt%) in order to obtain robust CE in DSSC. The structure and formation of PANI, GO and PANI/GO were characterized by Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analyses. The absorption spectra showed all the characteristic bands of GO, PANI(ES) and PANI/GO. Meanwhile, the incorporation of GO into PANI has enhanced the crystallinity of the composite. As a result, power conversion efficiency (PCE%) of the device with PANI/GO 3 wt% as the counter electrode reaches 6.39%. The excellent photoelectric properties, simple preparation procedure and inexpensive cost allow the PANI/GO electrode to be a credible alternative for DSSCs.

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Comparison between the Tensile, Water Absorption and Flammability Properties of Recycled High-Density Polyethylene/Rice Husk Composite from Twin-Screw Extruder and Heated Two-Roll Mill

2022-01-01 , Mohd Nazry Salleh , Roslaili Abdul Aziz , Shan C.R. , Luqman Musa , Mohd Fairul Sharin Abdul Razak , Nabialek M. , Jez B.

This study compares the mechanical properties of recycled high-density polyethylene (r-HDPE)/rice husk (RH) composites from a twin-screw extruder and a heated two-roll mill, and the effect of different filler loadings using different melt blending processes on the mechanical properties of r-HDPE/RH composites. Polyethylene-graft-maleic anhydride (MAPE) acts as the coupling agent to enhance interfacial bonding between the fibre and the polymer matrix. The filler loading used was in the range of 10-40 wt. %. In this work, r-HDPE/RH blends were prepared using a twin-screw extruder and a heated two-roll mill. The ratio of 70/30 twin-screw extruder compounded composites significantly showed higher tensile based on improved to about 45.5% at 11 MPa compared to those compounded in the heated two-roll mill. The same ratio showed an increment almost up to 9% of elongation at break. It has also been verified that the higher filler loading used reduced the tensile strength and elongation at break, while the Young's modulus increased. The result was evidenced by the increase in water absorption and longer burning time as the filler loading increased.

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Surface Modification of GO/TiO2 Thin Film by Sodium Dodecyl Sulphate for Photocatalytic Applications

2024-01-01 , Azliza Azani , Dewi Suriyani Che Halin , Mohd Arif Anuar Mohd Salleh , Kamrosni Abdul Razak , Mohd. Mustafa Al Bakri Abdullah , Muhammad Mahyiddin Ramli , Vizureanu P. , Mohd Fairul Sharin Abdul Razak , Sandu A.V. , Mohamad N.

Photocatalyst material titanium dioxide (TiO2) and graphene oxide (GO) were used to improve the self-cleaning properties of thin films. The sol–gel spin-coating method was successfully used to synthesize GO/TiO2 thin films. Surface modification was applied to optimize the self-cleaning capabilities by adding several concentrations of sodium dodecyl sulfate (SDS) (0.1 w/v%, 0.2 w/v%, 0.3 w/v%, 0.4 w/v%, and 0.5 w/v%) to the parent solution. The synthesized thin films were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction, UV-visible spectroscopy, water contact angle analysis, and photocatalytic analysis. The AFM and SEM images revealed that as the SDS amount increased, the particles became less agglomerated, and the roughness of the surface reduced from 2.54 × 102 nm to 0.83 × 102 nm. The wettability analysis showed that when SDS increased to 0.4 w/v%, the water contact angle dropped to 15.30°, implying that the thin film exhibits hydrophilic qualities. A decrease in the GO/TiO2 band gap was obtained linearly with the increase in SDS addition from 3.17 eV to 2.75 eV. Finally, the improvement of the surface coating and reduction of the band gap enhanced the photocatalytic activity, which degraded 78.97% of methylene blue, which was obtained by 0.4SDS.

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The effect of GO/TiO2 thin film during photodegradation of methylene blue dye

2021-09-01 , Azliza Azani , Dewi Suriyani Che Halin , Mohd. Mustafa Al Bakri Abdullah , Kamrosni Abdul Razak , Mohd Fairul Sharin Abdul Razak , Muhammad Mahyiddin Ramli , Mohd Arif Anuar Mohd Salleh , Chobpattana V.

Titanium (IV) isopropoxide (TTIP) was used to synthesize GO/TiO2 thin films using a sol-gel spin-coating method onto a glass substrate, undergoing an heat tretment at 350 °C. Several amounts of graphene oxide (GO) (0-20mg) were weighed into a sol solution of TiO2 to produce GO/TiO2 thin films. The thin film samples were characterized by X-ray diffraction (XRD) to analyze the samples’ phase and by scanning electron microscopy (SEM) to analyze the samples’ microstructure. Physical testing such as water contact angle (WCA) was analyzed using an optical microscope with J-Image software. In contrast, the optical band gap and photodegradation of methylene blue under sunlight irradiation of the thin film was analyzed using UV-VIS spectrophotometry. GO5 thin film sample showed low-intensity anatase phase formation, where the microstructure revealed a larger surface area with the addition of GO. WCA reveals that GO/TiO2 thin film exhibits super hydrophilic properties where the angle decreases from 37.83° to 4.11°. The optical result shows that GO has improved the absorption edges by expanding into visible regions. Moreover, due to the existence of GO 3.30 eV band gap energy of TiO2 decreases from to 3.18 eV obtained by GO5. The improved adsorption edge allows Ti3+, O2 and interstitial states to be formed in low valence states with energy underneath than in the TiO2 band gap. Therefore, the photodegradation of methylene blue (MB) dye increases from 48 % to 59 % in the GO/TiO2 thin film.

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Effect of Surface Treatment on Mechanical Properties of Rice Husk Reinforced Recycled High Density Polyethylene (rHDPE) Composites

2020-11-24 , Mohd Nazry Salleh , Roslaili Abdul Aziz , Mohd Fairul Sharin Abdul Razak , Luqman Musa , Ying H.L.

The aim of this work was to investigate the effect of surface treatment on rice husk reinforced recycled high density polyethylene (rHDPE) composites. Three types of surface treatment on rice husk were carried out which were maleated treatment, alkaline treatment and acrylic acid treatment. The characteristics and mechanical properties of the composites were analysed. The results for all treatments showed that tensile strength and break elongation of composites decreased significantly when the rice husk filler loading increased. Further findings showed that maleated treatment on rice husk can further enhance the mechanical properties due to the present of ester bond formed in FTIR analysis.

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Effect of surface treatment on water absorption of rice husk reinforced recycled high density polyethylene (RHDPE) composites.

2021-05-03 , Mohd Nazry Salleh , Roslaili Abdul Aziz , Luqman Musa , Mohamad Syahmie Mohamad Rasidi , Mohd Fairul Sharin Abdul Razak , Hong L.Y.

The goal of this study was to investigate the effect of surface treatment on rice husk reinforced recycled high density polyethylene (rHDPE) composites. Three types of surface treatments on rice husk were carried out which were maleated treatment, alkali treatment and acrylic acid treatment. Water absorption test was examined in distilled water. It showed that the lower the loading of rice husk, the lower the water absorption percentage. Maleated treatment on rice husk reinforced rHDPE has the highest resistance of water absorption tendency. Scanning electron microscope analysis of the composites showed that the lower the rice husk loading, the better the interfacial bonding of the composites. Maleated treatment of rice husk also showed that there is no gaps formed in the structure.

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Low temperature prepared N doped TiO2photodegradation of janus green B

2020-11-24 , Othman S.A. , Zainon S.N. , Abdullah M.F. , Nawawi W.I. , Ikhwan S. , Mohd Fairul Sharin Abdul Razak

N doped titanium dioxide (TiO2) was prepared under low temperature calcination of TiO2 Degussa P25 powder and urea at various mixing ratios. Muffle furnace was used as heating media with the temperature used in the range of 300 to 500 C. The prepared N doped TiO2 was characterized by using UV-Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). It was observed that N doped TiO2 prepared at 0.5 g urea under the 400 C calcination process (named as U2-400) is the optimum photocatalyst sample with the highest rate removal of Janus green B (JG) dye. The U2-400 had goes the photodegradation rate removal at 0.1071 min-1 where it is 3.5 times faster compared to unmodified TiO2 sample. The high photodegradation rate removal for U2-400 was due to the N incorporated with TiO2 in U2-400 photocatalyst which narrowed the bandgap energy from 3.2 to 3.0 eV as observed by UV-Vis DRS spectra. This shows the U2-400 sample has increased its photocatalytic activity since it has become more active under wider an optical response compared to the unmodified TiO2

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Effect of Photoetching Process onto Immobilized PANI/TiO2Films towards Photocatalytic Degradation of RR2 dye

2020-11-24 , Mohd Fairul Sharin Abdul Razak , Mohd Nazry Salleh , Nawawi W.I. , Natar N.

Polyaniline (PANI) and P-25 Titanium dioxide (TiO2) was fabricated as immobilized P-25TiO2/PANI/ENR/PVC film and reported on the photocatalytic study. PANI and TiO2 was immersed into the organic solvent and being coated onto glass plates under influenced of ENR/PVC polymeric binder by using a dip-coating method. It was found that, the removal of RR2 dye nearly good as suspension system after the pre-irradiation process. Based on COD and BET results, it showed that the optimum time of etching process was 7 hours irradiation time. This pre-irradiation process enhanced the removal of dye due to leached out of excessive binder and also exhibit visible light active after insertion of PANI into the immobilized system.

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Preparation of water-base immobilized N doped TiO2 using DSAT technique for photocatalytic degradation of methylene blue dye

2022-01-01 , Natar N.S. , Ikhwan S. , Nazeri N.S. , Hamzah S.R. , Rosli M.A. , Ghani N.I. , Ishak M.A.M. , Mohd Fairul Sharin Abdul Razak , Azami M.S. , Nawawi W.I.

Photocatalytic degradation of TiO2 photocatalyst under suspension mode has widely been studied among researchers. However, the application is limited due to the complexity in separation and non-recyclability of photocatalyst. Immobilization is one of the promising methods to overcome this problem. Most of the prepared immobilization modes showed lower photocatalytic activity compared with the suspension due to the chemical reaction of solvent with modified TiO2. Therefore, a free solvent or water-base preparation of immobilized TiO2 is critical in retaining its photocatalytic activity. Immobilization via double-sided adhesive tape (DSAT) was introduced previously by our research team, it works the best of others in replacing polymer binder in immobilization system making it a free solvent preparation process. The aim of this research is to prepare immobilized unmodified TiO2 and N doped TiO2 by using water-base DSAT technique. The presence of N element was detected for all modified N doped TiO2 samples confirmed by FTIR and EDX analysis. The N incorporated in modified TiO2 has reduced the band gap energy from 3.0 to 2.8 eV as observed by UV–Vis/DRS analysis. This explained the photoactivity under MB dye degradation is 2.1 times faster under N doped TiO2 where the photodegradation rate for unmodified and optimum N doped TiO2 (TN1-45) were 0.065 and 0.138 min−1 respectively. Immobilized TiO2/DSAT and TN1-450/DSAT have shown a significant photocatalytic performance where it was only reduced to 15% from suspension to immobilized mode. It can be considered higher performance as compared to the normal immobilization under solvent. It also better than suspension mode by considering of its reusability that able to sustain the photoactivity of immobilized TN1-450/DSAT for at least for 12 cycles.

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Synergistic effect of agarose biopolymer gel electrolyte with modified TiO2 for low-cost electrochemical device applications

2023-09-01 , Badri A. , Mohd Fairul Sharin Abdul Razak , Nawawi W.I. , Norhayati Sabani , Mohd Natashah Norizan , Abul Shukor A.

The effect of different concentrations of agarose gel electrolyte in a low-cost fabrication of DSSC system was investigated. The modified DSSC was fabricated by a sandwiched method using ITO glass plates as substrates. TiO2-Graphene-coated glass plate was used as the working electrode while PANI-GO-coated glass plate works as a counter electrode, respectively. Both electrodes were separated by agarose gel mixture with KI solution as gel biopolymer electrolyte. The FTIR result showed that peaks of agarose are well observed in the KI-agarose spectra. In the XRD analysis, the combination of KI-agarose has reduced the crystallinity of agarose which was good for ionic conductivity value. The addition of agarose in KI solution also produced a fine channel to facilitate the ionic transfer in electrolyte. The behaviour of electrochemical properties of the system was observed using AC impedance spectroscopy based on the Nyquist plot. From the plot, three semicircles were observed as the responses at different frequencies. It was observed that the 5 wt% agarose electrolyte in DSSC system was selected as the optimum loading exhibiting the lowest resistivity ensuring the faster electron transfer and giving the ionic conductivity of 9.04 × 10−1 S/cm. The ionic conductivity of the system was dropped at 2.21 × 10−1 S/cm as the percentage of agarose was increase to 6 wt%.