Article
Chemistry, Physical
Cafer Saka
Summary: The metal-free catalyst SP-KOH-P doped with phosphorus and oxygen was used to produce hydrogen from the methanolysis of NaBH4. The catalyst showed a high hydrogen production rate of 19,500 mL min(-1) g(-1) with an activation energy value of 38.79 kJ mol(-1).
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Biotechnology & Applied Microbiology
Soeun Moon, Youn-Jun Lee, Seong-Jik Park, Chang-Gu Lee
Summary: This study compared the performance of Spirulina-based adsorbents on the adsorption of ACT and BPA and found that ZnCl2-modified Spirulina biochar had the highest removal efficiency. The pseudo-second-order model was the best fitting model for adsorption kinetics, and the Redlich-Peterson model provided the best fit for the adsorption isotherm. The primary mechanisms driving the adsorption of ACT and BPA on ZnSB400 were pore filling and pi-pi interactions.
JOURNAL OF APPLIED PHYCOLOGY
(2023)
Article
Energy & Fuels
Peng Yin, L. Prabhu, S. N. Saranya, Sandhanasamy Devanesan, Mohamad S. Alsahi, A. Anderson, T. R. Praveenkumar
Summary: Severe environmental implications have resulted from the unsustainable demand for fossil fuels, such as greenhouse gas emissions and widespread pollution. In order to find sustainable alternatives, it is necessary to identify the primary challenges originating from these activities. The production potential of biodiesel from various types of biomass, such as Scenedesmus Dimorphus and spirulina, along with technological breakthroughs, has sparked interest in the energy sector.
Article
Chemistry, Physical
Cafer Saka
Summary: In this study, activated carbons prepared from microalgae with KOH activation were used for the first time as sulphur (S) and phosphorus (P) doped metal-free carbon catalysts in NaBH4 methanolysis reaction, showing a high hydrogen generation rate and low activation energy. After five cycles, the catalyst retained 59% of its initial catalytic activity, demonstrating the potential for environmentally friendly efficient catalytic reactions.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Energy & Fuels
Rajasree Shanmuganathan, Nguyen Thuy Lan Chi, Arunachalam Chinnathambi, Saleh H. Salmen, G. K. Jhanani, Beata Gavurova, Manigandan Sekar, Arivalagan Pugazhendhi, T. R. Praveenkumar
Summary: Extensive use of fossil fuels is the main cause of global warming. Biodiesel, as a promising alternative, can improve engine performance and reduce emissions when combined with nanoparticles and hydrogen. Among the blends tested, B20CH showed the lowest emissions.
Article
Energy & Fuels
Cafer Saka
Summary: Metal-free carbon catalysts doped with sulfur and phosphorus were prepared from activated carbon obtained from microalgae, showing high hydrogen generation rate and low activation energy in NaBH4 methanolysis. The catalytic activity was attributed to the synergistic effects of porous structure and P- and S-containing active sites, providing a new strategy for environmentally friendly efficient catalytic reactions.
Article
Biotechnology & Applied Microbiology
Adriyanus Ivan Pratama, Hanifah Nuryani Lioe, Nancy Dewi Yuliana, Masahiro Ogawa
Summary: The umami compounds in the acid-hydrolysate of Spirulina were investigated in this study. The Spirulina hydrolysate was found to have a higher umami intensity compared to unhydrolyzed one. A specific umami fraction was obtained by ultrafiltration and chromatography, containing high concentrations of succinic acid and free L-glutamic acid, as well as abundant glutamyl peptides.
ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS
(2022)
Article
Chemistry, Multidisciplinary
Duygu Elma Karakas, Mustafa Kaya, Sabit Horoz
Summary: This study aims to utilize waste banana peels as biomass and examine its contribution to hydrogen generation rate. The researchers used acid catalyst to functionalize the banana peels and found that it increased the hydrogen generation rate significantly and reduced the activation energy.
Article
Chemistry, Multidisciplinary
Cigdem Tuc Altaf, Valentina G. Minkina, Stanislav I. Shabunya, Tuluhan O. Colak, Nurdan Demirci Sankir, Mehmet Sankir, Vladimir I. Kalinin
Summary: Highly stable Ru and Pt-based catalysts on TiO2 nanoparticle support were prepared for hydrogen generation from NaBH4 hydrolysis. The activation energy and NaOH concentration had different effects on the efficiency of the two catalysts.
Article
Chemistry, Physical
Jiale Shen, Danyun Xu, Jian Ji, Qicheng Zhang, Xiaobin Fan
Summary: A facile method is developed to synthesize defects-rich TiO2 supported CoB nanoparticles (CoB/TiO2-x) for efficient NaBH4 hydrolysis. The as-synthesized CoB/TiO2-x catalyst exhibits good catalytic performance with a hydrogen generation rate of 3070 mL min-1 gCo-1 and an activation energy of 57.03 kJ mol-1.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Environmental Sciences
Hadiyanto Hadiyanto, Amnan Haris, Fuad Muhammad, Norma Afiati, Adian Khoironi
Summary: This study examined the interaction between Styrofoam and S. platensis, revealing that Styrofoam stress can stimulate the growth of S. platensis and induce changes in the functional groups of Styrofoam. The results suggest that Styrofoam can serve as a nutrient source, particularly carbon, for S. platensis photosynthesis, but it may also cause damage to the cells of S. platensis.
Article
Chemistry, Physical
Nicole Longtin, Daniela Oliveira, Aishwarya Mahadevan, Varun Gejji, Carmen Gomes, Sandun Fernando
Summary: In this study, a unique configuration of Spirulina-based microalgal fuel cell was tested, showing highest performance on day seven during the exponential growth phase. Additionally, the highest power density was achieved when three fuel cells were connected in parallel.
JOURNAL OF POWER SOURCES
(2021)
Review
Food Science & Technology
Debora Pez Jaeschke, Ingrid Rocha Teixeira, Ligia Damasceno Ferreira Marczak, Giovana Domeneghini Mercali
Summary: The industrial application of Phycocyanin (C-PC) is limited by the drawbacks of extraction methods and the low stability of compounds post-extraction. Alternative extraction methodologies have been explored, with pulsed electric field (PEF) showing promise for high purity C-PC extraction. Stabilizing agents, such as natural polymers and sugars, are being used to prevent degradation of C-PC content during storage and food processing, aiming to retain color and antioxidant activity.
FOOD RESEARCH INTERNATIONAL
(2021)
Article
Chemistry, Physical
Asim Balbay, Nuran Selvitepe, Cafer Saka
Summary: This study explored the use of modified montmorillonite clay as a support material for Co-B and Co-Fe-B catalysts in hydrogen generation reactions. By investigating the effects of different acids and various parameters of the catalyst, optimal activation conditions and hydrogen generation efficiency were identified.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Biotechnology & Applied Microbiology
Pei Han, Jingjing Li, Huiqi Zhong, Jiawen Xie, Peidong Zhang, Qian Lu, Jun Li, Peilun Xu, Paul Chen, Lijian Leng, Wenguang Zhou
Summary: Spirulina is rich in antioxidants that can improve symptoms induced by oxidative stress, showing strong anti-oxidation properties and potential as therapeutic antioxidants.
ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS
(2021)
Article
Chemistry, Analytical
Cafer Saka, Gulten Elci Olcenoglu, Omer Sahin
Summary: The petroleum coke sample (PCS) was successfully modified for the first time by oxygen plasma treatment (OPT), increasing the new active groups containing oxygen on the PCS surface, and removing malachite green dye from the aqueous medium.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Analytical
Ibrahim Tegin, Cafer Saka
Summary: This study investigated the removal of methylene blue by both raw and modified clay, with the modified clay showing significant improvements in adsorption capacity. The modification process included calcination, acid treatment, and second calcination, with factors such as calcination temperature and acid/base concentration affecting the adsorption capacity. Characterization of the clay was done by SEM and FTIR, and Langmuir and Freundlich isotherm models were used to analyze the results.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
(2023)
Article
Energy & Fuels
Cafer Saka
Summary: Phosphorus-doped graphitic carbon nitride (gC3N4) has been used as a catalyst in the dehydrogenation of sodium borohydride (NaBH4) methanolysis for the first time. The reaction parameters including interaction time, NaBH4 concentration, catalyst amount, and temperature were investigated. The results showed that the catalyst had good performance in the reaction, and its activity was affected by the above-mentioned parameters.
Article
Environmental Sciences
I Tegin, M. S. Batur, O. Yavuz, C. Saka
Summary: This study investigates a low-cost and economical heat-treated clay sample as a potential adsorbent for the removal of Cu(II), Pb(II) and Cd(II) ions from aqueous solutions. The results show that the adsorption ability of the heat-treated clay adsorbent is significantly improved compared to the raw clay sample.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
(2023)
Article
Environmental Sciences
Cafer Saka, Yavuz Yardim, Omer Sahin, Orhan Baytar
Summary: This study investigates the application of chestnut shell-based activated carbon in iodine adsorption and as an electrochemical double-layer capacitor material. The results show that chestnut shell-based activated carbon exhibits excellent performance in adsorption and capacitor properties.
INTERNATIONAL JOURNAL OF PHYTOREMEDIATION
(2023)
Article
Chemistry, Physical
Yasar Genel, Ilyas Genel, Cafer Saka
Summary: Activated carbons synthesized from the ash tree were found to be effective adsorbents for removing methylene blue from aqueous solutions. The carbonaceous materials exhibited mesoporous structures and active functional groups. The highest adsorption capacities were obtained with chemical activation using zinc chloride and sodium hydroxide.
FULLERENES NANOTUBES AND CARBON NANOSTRUCTURES
(2023)
Article
Chemistry, Physical
Cafer Saka
Summary: This study focuses on the production of two-stage metal-free catalysts from pistachio shells. The first stage involves the production of activated carbon (AC), while the second stage involves the production of catalysts doped with heteroatoms through hydrothermal heating of the obtained activated carbon with nitric acid. The metal-free catalysts are then used for hydrogen production from sodium borohydride (NaBH4) in methanol.
Article
Materials Science, Multidisciplinary
Cafer Saka, Ibrahim Tegin, Kubra Kahvecioglu
Summary: This study focuses on enhancing the adsorption capacity of activated carbon by sulphur doping, using almond shells as the base material. The results showed that sulphur doped activated carbon exhibits high adsorption performance for Cd(II) and follows Langmuir isotherm and pseudo-second-order kinetic models.
DIAMOND AND RELATED MATERIALS
(2023)
Article
Environmental Sciences
Kubra Kahvecioglu, Ibrahim Tegin, Omer Yavuz, Cafer Saka
Summary: In this study, activated carbon based on almond shells was produced through microwave heating and then modified with phosphorus and oxygen through hydrothermal heating. The modified activated carbon showed improved adsorption efficiency for Cd(II) and Pb(II) ions. The results indicated that the modified activated carbon follows Langmuir isotherm and pseudo-second-order kinetics for adsorption of both Cd(II) and Pb(II).
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Chemistry, Physical
Cafer Saka
Summary: The surface properties of graphitic carbon nitride (GCN) were enhanced by doping with sulphur (S), boron (B), and oxygen (O). Metal-free GCN catalysts with heteroatom dopants showed improved surface functional groups and a carbon defect structure. These catalysts were used for hydrogen production from sodium borohydride (SB) methanolysis, resulting in a 2.2-fold increase in H2 production compared to GCN. The HGR value obtained with B, O, and S doped GCN was 9166 ml min-1g-1. XPS, SEM-EDX, TEM, FTIR, and XRD analyses were performed to investigate the structural properties of the catalysts, and the activation energy (Ea) for B, O, and S doped GCN was determined to be 28.89 kJ mol-1.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Cafer Saka
Summary: Hybrid kaolin-g-C3N4 heterostructure particles were fabricated and phosphorus and oxygen doped kaolin-g-C3N4 metal-free catalyst was synthesized for the first time for effective hydrogen production from sodium borohydride methanolysis. The catalyst showed a hydrogen generation rate of 5500 ml min-1g-1 and an activation energy of 31.90 kJ mol-1. The kaolin-g-C3N4 and doped catalysts were characterized by various techniques, and a mechanism for hydrogen production was proposed.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Materials Science, Multidisciplinary
Cetin Murtazaoglu, Ibrahim Tegin, Cafer Saka
Summary: In this study, activated carbon (AC) was produced from pistachio shells using potassium hydroxide (KOH) activation, and then modified with hydrogen peroxide (H2O2). The modified AC (KOH-AC-H2O2) was found to effectively adsorb Cu (II) and Zn (II) ions from wastewater, with adsorption behavior in accordance with the Langmuir isotherm model.
DIAMOND AND RELATED MATERIALS
(2023)
Article
Chemistry, Physical
Yavuz Yardim, Cafer Saka
Summary: This study investigated the thermal activation of Chlorella vulgaris and Spirulina platensis microalgae using potassium hydroxide (KOH) in a carbon dioxide (CO2) atmosphere, followed by the hydrothermal interaction with nitric acid to form nitrogen and oxygen-doped activated carbons. These carbons were then used to fabricate electrochemical supercapacitors. The morphological properties of the obtained pores were characterized by transmission electron microscopy (TEM), and the electrochemical properties were evaluated by cyclic voltammetry (CV) in different electrolytes. The results showed that the nitrogen and oxygen-doped electrode based on Spirulina platensis microalgae exhibited the highest specific capacitance of 99.53 Fg(-1) in a 1 M H2SO4 electrolyte, while the supercapacitor based on the activated carbon electrode from Chlorella vulgaris microalgae showed the highest specific capacitance of 156.04 Fg(-1) in a 1 M KCl electrolyte.
FULLERENES NANOTUBES AND CARBON NANOSTRUCTURES
(2023)
Article
Energy & Fuels
Cafer Saka, Ibrahim Tegin, Kubra Kahvecioglu, Omer Yavuz
Summary: In this study, a two-step method was employed to produce an effective adsorbent for the adsorption of cadmium (Cd) (II) and lead (Pb)(II). The method involved the preparation of activated carbon (AC) from almond shells using microwave heating and potassium hydroxide (KOH), followed by nitrogen and oxygen doping through hydrothermal treatment with nitric acid. The resulting materials were characterized and their adsorption performance, mechanism, kinetics, and thermodynamics were evaluated. The nitrogen- and oxygen-doped ACs exhibited good adsorption capacity for Cd (II) and Pb (II), with values of 106.38 mg/g and 76.33 mg/g, respectively.
BIOMASS CONVERSION AND BIOREFINERY
(2023)
Article
Environmental Sciences
Cafer Saka
Summary: In this study, phosphorus and boron-doped graphitic carbon nitride/zeolite catalysts were prepared under three-step heating conditions. The catalysts were characterized using various techniques, and it was found that they can be used as metal-free catalysts for hydrogen production from sodium borohydride in methanol. The hydrogen production rate for these catalysts was measured to be 6250 ml min(-1) g(-1), which is reported for the first time in the literature.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
