Takwa E. Ellakwa, A. A. H. Basry, Sawsan M. Abu El Hassan
The kinetics of the oxidation of the [Co(L)2(H2O)2] complex by N-bromosuccinimide (NBS) in aqueous media (L = bidentate ligand mono deprotonated anion derived from methyl salicylaldehyde and sulfacetamide) were investigated over a pH range of 4.2–5.4, temperatures ranging from 25°C to 40°C, and an ionic strength of 0.1 mol/l–0.4 mol/l for both NBS and complex concentrations. The reaction rate over the studied pH ranges was predicted to be first order NBS and complex dependent and to rise with decreasing [H+]. It was compatible with the experimental rate law to say that a process in which the complex’s dehydrogenated form is greater reactivity compared to its conjugate acid. Acrylonitrile polymerisation was tested for its abundance of free radicals in the reaction admixture. It was supposed that transfer of electrons and formation of initial cobalt(III) products, which were eventually were tardily transformed into the final cobalt(III) products, occurred by an inner-sphere mechanism.
{"title":"A Kinetic Study of Oxidation of New [Co(L)2(H2O)2] Complex by N-bromosuccinimide (NBS)","authors":"Takwa E. Ellakwa, A. A. H. Basry, Sawsan M. Abu El Hassan","doi":"10.21315/jps2023.34.3.6","DOIUrl":"https://doi.org/10.21315/jps2023.34.3.6","url":null,"abstract":"The kinetics of the oxidation of the [Co(L)2(H2O)2] complex by N-bromosuccinimide (NBS) in aqueous media (L = bidentate ligand mono deprotonated anion derived from methyl salicylaldehyde and sulfacetamide) were investigated over a pH range of 4.2–5.4, temperatures ranging from 25°C to 40°C, and an ionic strength of 0.1 mol/l–0.4 mol/l for both NBS and complex concentrations. The reaction rate over the studied pH ranges was predicted to be first order NBS and complex dependent and to rise with decreasing [H+]. It was compatible with the experimental rate law to say that a process in which the complex’s dehydrogenated form is greater reactivity compared to its conjugate acid. Acrylonitrile polymerisation was tested for its abundance of free radicals in the reaction admixture. It was supposed that transfer of electrons and formation of initial cobalt(III) products, which were eventually were tardily transformed into the final cobalt(III) products, occurred by an inner-sphere mechanism.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138984197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The spectrophotometric method monitored the uncatalysed redox reaction between Mn+7/H+ ions and mannose sugar molecules kinetically at constant ionic strength maintained using potassium nitrate (KNO3). The kinetic study showed that the reaction was pseudo-first order concerning Mn+7 and mannose, and the rate of reaction increases by increasing the concentration of Mn+7, mannose and H+ and increasing temperature. The reaction rate was enhanced by 3 × 10–4m of Mn+7 concentration, and the oxidation with Mn+7 was faster using 2 × 10–2m of mannose and 5 × 10–1m of H+. The temperature dependence was carried out under fixed experimental conditions, from which the activation energy of the reaction (Ea) in KJ.mol–1 was found to be 61.1, and the frequency factor (A) in sec–1 was 10.52 × 105 other physical functions, namely, the free energy change (∆G) in KJ.mol–1 and the entropy change (∆S) in J.K –1 were also calculated at different temperatures. Qualitative analysis of the reaction products revealed the formation of formic acid. A rate law was derived from the proposed mechanism, which agreed well with experimental kinetics.
{"title":"The Kinetic Behaviour of Mn+7/H+ Ions Towards Mannose Molecule","authors":"Mustafa Jaip Allah Abdelmageed Abualreish","doi":"10.21315/jps2023.34.3.2","DOIUrl":"https://doi.org/10.21315/jps2023.34.3.2","url":null,"abstract":"The spectrophotometric method monitored the uncatalysed redox reaction between Mn+7/H+ ions and mannose sugar molecules kinetically at constant ionic strength maintained using potassium nitrate (KNO3). The kinetic study showed that the reaction was pseudo-first order concerning Mn+7 and mannose, and the rate of reaction increases by increasing the concentration of Mn+7, mannose and H+ and increasing temperature. The reaction rate was enhanced by 3 × 10–4m of Mn+7 concentration, and the oxidation with Mn+7 was faster using 2 × 10–2m of mannose and 5 × 10–1m of H+. The temperature dependence was carried out under fixed experimental conditions, from which the activation energy of the reaction (Ea) in KJ.mol–1 was found to be 61.1, and the frequency factor (A) in sec–1 was 10.52 × 105 other physical functions, namely, the free energy change (∆G) in KJ.mol–1 and the entropy change (∆S) in J.K –1 were also calculated at different temperatures. Qualitative analysis of the reaction products revealed the formation of formic acid. A rate law was derived from the proposed mechanism, which agreed well with experimental kinetics.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138984572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electron beam irradiation (EBI) (100−400 kGy) was utilised to pretreat water hyacinth (WH). Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), fourier transform infrared (FTIR), UV-vis absorption and fluorescence spectroscopy were used to examine the effects of EBI and hydrothermal temperatures on the physical, chemical and optical characteristics of carbon dots (CDs). The combination of 400 kGy-pretreatment and 250°C-hydrothermal treatment as the optimal condition for CDs synthesis provided the highest quantum yield (QY) of 14.5% and the product yield of 7.5%. Using dynamic light scattering (DLS), the CDs showed an average size of around 180 nm, and the zeta potential analysis revealed the overall negative charge on the CDs’ surface. In comparison, the CDs synthesised via hydrothermal conversion at 250°C without EBI showed a QY of only 4.0% and a product yield of 3.8%, significantly lower than the condition with 400 kGy-pretreatment. The improved optical characteristics of the CDs could result from the high nitrogen contents of WH biomass, oxygen-rich surfaces from EBI pretreatment at 400 kGy and the aromatic skeleton of the CDs.
{"title":"Irradiation-Assisted Hydrothermal Conversion of Water Hyacinth Leaves to Fluorescence Carbon Dots with High Quantum Yield","authors":"Tanagorn Kwamman, Threeraphat Chutimasakul, Panida Sangangam, Nattamon Puengposop, Pattanapong Thangsunan, Tinutda Phonlam, Kanokorn Wechakorn","doi":"10.21315/jps2023.34.2.4","DOIUrl":"https://doi.org/10.21315/jps2023.34.2.4","url":null,"abstract":"Electron beam irradiation (EBI) (100−400 kGy) was utilised to pretreat water hyacinth (WH). Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), fourier transform infrared (FTIR), UV-vis absorption and fluorescence spectroscopy were used to examine the effects of EBI and hydrothermal temperatures on the physical, chemical and optical characteristics of carbon dots (CDs). The combination of 400 kGy-pretreatment and 250°C-hydrothermal treatment as the optimal condition for CDs synthesis provided the highest quantum yield (QY) of 14.5% and the product yield of 7.5%. Using dynamic light scattering (DLS), the CDs showed an average size of around 180 nm, and the zeta potential analysis revealed the overall negative charge on the CDs’ surface. In comparison, the CDs synthesised via hydrothermal conversion at 250°C without EBI showed a QY of only 4.0% and a product yield of 3.8%, significantly lower than the condition with 400 kGy-pretreatment. The improved optical characteristics of the CDs could result from the high nitrogen contents of WH biomass, oxygen-rich surfaces from EBI pretreatment at 400 kGy and the aromatic skeleton of the CDs.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135236171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ahmad Solehin Ab Sabar, Syaza Azhari, Nur Atiqah Nasir, Muhammad Zamir Othman
A direct, simple and low-cost approach to synthesising carbon aerogelmagnesium (CA-Mg) composites has been demonstrated in this research. It is conducted by carbonising sodium carboxymethyl cellulose (CMC) aerogels via a sol-gel and freezedrying process. Mg is used as an enhancer for CA in the preparation step and as a selective candidate for the hydrogen storage device. Note that the structure and morphology of CA-Mg composites are characterised using field emission scanning electron microscopy (FESEM), fourier transforms infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques. The ability of CA-Mg composites to act as a hydrogen storage device is analysed by utilising Brunauer-Emmett-Teller (BET) and temperature-programmed desorption analysis. The CA-Mg composites comprise porous structures with a high specific surface area of 101.4407 m2 /g, and 0.002 mol of Mg2+ is the optimum concentration for synthesising CA-Mg composites. As a potential candidate for a hydrogen storage device, the CA-Mg composites show an initial dehydrogenation temperature of 377.22°C, where they desorbed the maximum amount of hydrogen gas. This study emphasises the potential for using CA as a hydrogen storage device, which fulfils the seventh goal of the Sustainable Development Goals (SDGs), affordable and clean energy, as well as Department of Energy (DOE)’s goal of using carbon-based materials.
{"title":"Synthesis and Characterisation of Carbon Aerogel Derived from Carboxymethyl Cellulose as Hydrogen Storage Material","authors":"Ahmad Solehin Ab Sabar, Syaza Azhari, Nur Atiqah Nasir, Muhammad Zamir Othman","doi":"10.21315/jps2023.34.2.2","DOIUrl":"https://doi.org/10.21315/jps2023.34.2.2","url":null,"abstract":"A direct, simple and low-cost approach to synthesising carbon aerogelmagnesium (CA-Mg) composites has been demonstrated in this research. It is conducted by carbonising sodium carboxymethyl cellulose (CMC) aerogels via a sol-gel and freezedrying process. Mg is used as an enhancer for CA in the preparation step and as a selective candidate for the hydrogen storage device. Note that the structure and morphology of CA-Mg composites are characterised using field emission scanning electron microscopy (FESEM), fourier transforms infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques. The ability of CA-Mg composites to act as a hydrogen storage device is analysed by utilising Brunauer-Emmett-Teller (BET) and temperature-programmed desorption analysis. The CA-Mg composites comprise porous structures with a high specific surface area of 101.4407 m2 /g, and 0.002 mol of Mg2+ is the optimum concentration for synthesising CA-Mg composites. As a potential candidate for a hydrogen storage device, the CA-Mg composites show an initial dehydrogenation temperature of 377.22°C, where they desorbed the maximum amount of hydrogen gas. This study emphasises the potential for using CA as a hydrogen storage device, which fulfils the seventh goal of the Sustainable Development Goals (SDGs), affordable and clean energy, as well as Department of Energy (DOE)’s goal of using carbon-based materials.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134932018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cooperative dynamics in pure cyclohexanol (CYN), xylene and their binary solutions have been studied using dielectric relaxation spectroscopy (DRS) in 10 MHz to 30 GHz microwave frequency range. The dynamics in CYN-CYN, CYN-xylene molecules have been explained using concept of cooperative domains (CDs). Deviations in CYN-xylene binary solutions exist due to braking and making of bonds as well as selfassociation among the molecules. Kirkwood correlation factor authenticates CDs with diverse exchanges through hydrogen bonding. Luzar model offers moderately decent qualitative values of εo such that the theoretically calculated values found relatively good in comparison with experimental results.
{"title":"Study of Co-operative Dynamics in Cyclohexanol-Xylene Solutions using Dielectric Relaxation Spectroscopy","authors":"Sangameshwar Sanjivan Birajdar, Ashok Champatrao Kumbharkhane, Deelip Baliram Suryawanshi","doi":"10.21315/jps2023.34.2.7","DOIUrl":"https://doi.org/10.21315/jps2023.34.2.7","url":null,"abstract":"Cooperative dynamics in pure cyclohexanol (CYN), xylene and their binary solutions have been studied using dielectric relaxation spectroscopy (DRS) in 10 MHz to 30 GHz microwave frequency range. The dynamics in CYN-CYN, CYN-xylene molecules have been explained using concept of cooperative domains (CDs). Deviations in CYN-xylene binary solutions exist due to braking and making of bonds as well as selfassociation among the molecules. Kirkwood correlation factor authenticates CDs with diverse exchanges through hydrogen bonding. Luzar model offers moderately decent qualitative values of εo such that the theoretically calculated values found relatively good in comparison with experimental results.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134932015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohamad Alif Adnan, Muhd Izzudin Fikry Zainuddin, Abdul Latif Ahmad
Carbon dioxide (CO2) capture utilising membrane technology have become the interest of research due to its low carbon footprint, feasible fabrication process and scalability in its operation. In this study, anisotropic polyethersulfone (PES) membrane was fabricated at various concentration ranging from 20 wt% to 35 wt% without the use of any additives. This study revealed that the finger-like structure disappeared with increased polymer dope concentration which was associated with increased viscosity of the dope solution. Moreover, the surface porosity of the membrane also virtually reduced with increased PES concentration as observed with the SEM images. The pure gas permeation test was also consistent with the observed morphology of the membrane. Membrane made with 20 wt% of PES dope solution exhibits the highest gas permeance which was 154.9 GPU at 2 bar while the CO2/nitrogen (N2) and CO2/methane (CH4) ideal selectivity was close to that of Knudsen’s selectivity value. With increased PES concentration, the CO2 gas permeance reduced drastically accompanied by enhancement on the CO2/N2 and CO2/ CH4 ideal selectivity. The critical concentration of PES dope solution obtained by plotting the PES dope concentration against viscosity was 29.4 wt%. With critical concentration of the dope solution, the CO2 permeance was recorded to be 8.1 GPU while the CO2/N2 and CO2/CH4 ideal selectivity were recorded to be 2.13 and 1.48, respectively at the pressure of 2 bar.
{"title":"The Effect of Concentration on PES/NMP System on Flat Sheet Membrane Fabrication and its Performance for CO2 Gas Separation","authors":"Mohamad Alif Adnan, Muhd Izzudin Fikry Zainuddin, Abdul Latif Ahmad","doi":"10.21315/jps2023.34.2.8","DOIUrl":"https://doi.org/10.21315/jps2023.34.2.8","url":null,"abstract":"Carbon dioxide (CO2) capture utilising membrane technology have become the interest of research due to its low carbon footprint, feasible fabrication process and scalability in its operation. In this study, anisotropic polyethersulfone (PES) membrane was fabricated at various concentration ranging from 20 wt% to 35 wt% without the use of any additives. This study revealed that the finger-like structure disappeared with increased polymer dope concentration which was associated with increased viscosity of the dope solution. Moreover, the surface porosity of the membrane also virtually reduced with increased PES concentration as observed with the SEM images. The pure gas permeation test was also consistent with the observed morphology of the membrane. Membrane made with 20 wt% of PES dope solution exhibits the highest gas permeance which was 154.9 GPU at 2 bar while the CO2/nitrogen (N2) and CO2/methane (CH4) ideal selectivity was close to that of Knudsen’s selectivity value. With increased PES concentration, the CO2 gas permeance reduced drastically accompanied by enhancement on the CO2/N2 and CO2/ CH4 ideal selectivity. The critical concentration of PES dope solution obtained by plotting the PES dope concentration against viscosity was 29.4 wt%. With critical concentration of the dope solution, the CO2 permeance was recorded to be 8.1 GPU while the CO2/N2 and CO2/CH4 ideal selectivity were recorded to be 2.13 and 1.48, respectively at the pressure of 2 bar.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134932019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Budi Purnama, Arga Dwi Suwandi, Rudi Hartono, Sahirul Alim Tri Bawono, Utari Utari, Herman Aldila, Adi Rahwanto, Kusumandari Kusumandari
Cobalt ferrite (CoFe2O4) nanopowder was successfully synthesised by the coprecipitation method. For the entire experiment, natural iron sand from the Bengawan Solo River is used as an iron (Fe) cation source. The effect of the annealing temperature of a coprecipitated CoFe2O4 sample from natural iron sand was investigated. The presence of strong metal oxide bond groups at the tetrahedral and octahedral sites is revealed by fourier transform infrared (FTIR) spectral results, owing to the CoFe2O4 characteristic. Then the X-ray diffraction (XRD) pattern confirmed the formation of a single-phase CoFe2O4 with face centred cubic (FCC) crystal structure closely matched to reference data ICDD221086. The crystalline parameters such as lattice parameter and crystallite size modify with the increase of annealing temperature. The saturation magnetisation (Ms) decreases as the annealing temperature rises. In addition, the coercive fields (Hc) increases as the annealing temperature rises. As a result, the annealing temperature affects the performance of the CoFe2O4 photocatalyst. The photocatalytic performance of the annealing temperature sample at 300°C was found to be the best.
{"title":"Annealing Temperature Dependence on Magnetic Properties, Crystalline Structure and Photocatalyst Activity of Coprecipitated Cobalt Ferrite (CoFe2O4) Synthesised from Natural Iron Sand","authors":"Budi Purnama, Arga Dwi Suwandi, Rudi Hartono, Sahirul Alim Tri Bawono, Utari Utari, Herman Aldila, Adi Rahwanto, Kusumandari Kusumandari","doi":"10.21315/jps2023.34.2.6","DOIUrl":"https://doi.org/10.21315/jps2023.34.2.6","url":null,"abstract":"Cobalt ferrite (CoFe2O4) nanopowder was successfully synthesised by the coprecipitation method. For the entire experiment, natural iron sand from the Bengawan Solo River is used as an iron (Fe) cation source. The effect of the annealing temperature of a coprecipitated CoFe2O4 sample from natural iron sand was investigated. The presence of strong metal oxide bond groups at the tetrahedral and octahedral sites is revealed by fourier transform infrared (FTIR) spectral results, owing to the CoFe2O4 characteristic. Then the X-ray diffraction (XRD) pattern confirmed the formation of a single-phase CoFe2O4 with face centred cubic (FCC) crystal structure closely matched to reference data ICDD221086. The crystalline parameters such as lattice parameter and crystallite size modify with the increase of annealing temperature. The saturation magnetisation (Ms) decreases as the annealing temperature rises. In addition, the coercive fields (Hc) increases as the annealing temperature rises. As a result, the annealing temperature affects the performance of the CoFe2O4 photocatalyst. The photocatalytic performance of the annealing temperature sample at 300°C was found to be the best.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134932016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abdullah Taha Ali, Wan Maryam Wan Ahmad Kamil, Sheng-Chan Wu, Chung-Xian Yang, Hsu-Cheng Hsu, Faisal Rafiq Mahamd Adikan, Ghafour Amouzad Mahdiraji, Fairuz Abdullah
Random lasing from a solid-state gain medium prepared on photonic crystal fibre (PCF) is observed for the first time. Vertically aligned ZnO microrods were prepared on PCF using a simple technique of chemical bath deposition (CBD). A low lasing threshold of 12.2 mJ/cm2 was observed in sample with longer zinc oxide (ZnO) rod length. The variation in morphology and population density did not affect the lasing threshold significantly. Further investigation of the effect of fiber length revealed that a shorter fiber had a lower threshold and showed quenching of the spontaneous emission revealing better lasing output. Simulations based on the morphology of the gain medium revealed light confinement in the structure, validating the origin of the lasing emission. Overall, this study shows the potential of utilising optical fiber as random lasers with a sustainable solid state gain medium.
{"title":"Random Laser Emission from Fiber coated ZnO","authors":"Abdullah Taha Ali, Wan Maryam Wan Ahmad Kamil, Sheng-Chan Wu, Chung-Xian Yang, Hsu-Cheng Hsu, Faisal Rafiq Mahamd Adikan, Ghafour Amouzad Mahdiraji, Fairuz Abdullah","doi":"10.21315/jps2023.34.2.3","DOIUrl":"https://doi.org/10.21315/jps2023.34.2.3","url":null,"abstract":"Random lasing from a solid-state gain medium prepared on photonic crystal fibre (PCF) is observed for the first time. Vertically aligned ZnO microrods were prepared on PCF using a simple technique of chemical bath deposition (CBD). A low lasing threshold of 12.2 mJ/cm2 was observed in sample with longer zinc oxide (ZnO) rod length. The variation in morphology and population density did not affect the lasing threshold significantly. Further investigation of the effect of fiber length revealed that a shorter fiber had a lower threshold and showed quenching of the spontaneous emission revealing better lasing output. Simulations based on the morphology of the gain medium revealed light confinement in the structure, validating the origin of the lasing emission. Overall, this study shows the potential of utilising optical fiber as random lasers with a sustainable solid state gain medium.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134932022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ari Sulistyo Rini, Rahmi Dewi, Jasril Jasril, Tessa Marshanda, Yolanda Rati, Yan Soerbakti
Photocatalytic is one of the technological developments of renewable materials in overcoming water pollution due to industrial waste treatment. In this study, photocatalytic observations were carried out with a methylene blue (MB) degradation approach using zinc oxide and silver (ZnO/Ag) nanocomposites (NCs) which were enhanced by a new green synthesis in the form of pineapple peel extract (Ananas comosus) as a bio-stabiliser. The amount of Ag was varied by 5%, 10% and 15%. UV-Vis spectroscopy (UV-Vis), X-ray diffrection (XRD) and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) spectroscopy were analysed to study the optical properties, structure, morphology and composition of the samples. The characterisation results show that the absorption peak occurs in the 359 nm to 368 nm region with a band gap energy of 2.96 eV to 3.00 eV. Based on the XRD pattern, a hexagonal wurtzite structure was obtained with a crystal size of 18.37 nm. The particle morphology shows a flower-like shape with an average diameter of 60 nm. The EDX spectrum confirmed the elemental content of Zn, oxygen (O) and Ag. The photocatalytic activity showed that 10% ZnO/Ag was able to optimally degrade MB (10 ppm) with a reaction rate constant of 0.0091 min−1. Therefore, ZnO/Ag NCs were proven to be able to degrade dyes faster than pure ZnO.
{"title":"Synthesis and Characterisation of ZnO/Ag Nanocomposites Prepared via Green Method Using Pineapple Peel Extract for Photocatalytic Enhancement in Degrading Methylene Blue Dye Solutions","authors":"Ari Sulistyo Rini, Rahmi Dewi, Jasril Jasril, Tessa Marshanda, Yolanda Rati, Yan Soerbakti","doi":"10.21315/jps2023.34.2.5","DOIUrl":"https://doi.org/10.21315/jps2023.34.2.5","url":null,"abstract":"Photocatalytic is one of the technological developments of renewable materials in overcoming water pollution due to industrial waste treatment. In this study, photocatalytic observations were carried out with a methylene blue (MB) degradation approach using zinc oxide and silver (ZnO/Ag) nanocomposites (NCs) which were enhanced by a new green synthesis in the form of pineapple peel extract (Ananas comosus) as a bio-stabiliser. The amount of Ag was varied by 5%, 10% and 15%. UV-Vis spectroscopy (UV-Vis), X-ray diffrection (XRD) and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) spectroscopy were analysed to study the optical properties, structure, morphology and composition of the samples. The characterisation results show that the absorption peak occurs in the 359 nm to 368 nm region with a band gap energy of 2.96 eV to 3.00 eV. Based on the XRD pattern, a hexagonal wurtzite structure was obtained with a crystal size of 18.37 nm. The particle morphology shows a flower-like shape with an average diameter of 60 nm. The EDX spectrum confirmed the elemental content of Zn, oxygen (O) and Ag. The photocatalytic activity showed that 10% ZnO/Ag was able to optimally degrade MB (10 ppm) with a reaction rate constant of 0.0091 min−1. Therefore, ZnO/Ag NCs were proven to be able to degrade dyes faster than pure ZnO.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134932017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohd Aiman Hakimi Abdul Rahim, Siti Fatimah Samsurrijal, Amirul Al-Ashraf Abdullah, Siti Noor Fazliah Mohd Noor
Liquid-phase exfoliation of graphene using a suitable solvent is safe, although the sonication period needs further exploration, which may affect the exfoliation process. This study investigated graphene exfoliation in chloroform through UV–Vis spectroscopy. Graphite powder at different ratios was soaked in chloroform and sonicated at different sonication times from 30 min to 180 min and then subjected to centrifugation at 4,000 rpm for 30 min. The supernatant was collected and analysed using UV–Vis spectroscopy at wavelengths between 220 nm and 800 nm. The UV absorbance intensity showed that the presence of exfoliated graphene peaks is free of interference at 120 min. A comparative study was conducted by using graphene in chloroform as controls and adding bioactive glass (BG) within graphite powder-chloroform emulsions in different concentrations at 120 min. Graphene appearance at the anticipated absorption peak at ~270 nm was observed, and BG addition led to agglomeration, which could provide an idea for a better material formulation strategy in developing films that combined graphene/ BG because of their exceptional properties suitable for diverse potential biomedical application.
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