Article
Chemistry, Physical
Lijing Yang, Congmin Fan, Jiapeng Zhang, Fengming Zhang, Ran Li, Shuang Yi, Yue Sun, Hua Dong
Summary: A SiO2@PAA catalyst composed of silica nanoparticles modified with poly(acrylic acid) was developed for NaBH4 methanolysis, showing excellent catalytic performance. The catalyst exhibited significantly higher hydrogen generation rate and lower activation energy compared to unmodified silica. Furthermore, the catalytic activity of the SiO2@PAA catalyst could be restored after regeneration with diluted hydrochloric acid solution.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Cafer Saka, Asim Balbay
Summary: For the first time, phosphoric acid and acetic acid catalysts were used for efficient hydrogen production from sodium borohydride ethylene glycolysis reaction. The experimental results showed that the presence of water negatively affects H-2 production. The hydrogen generation rate obtained with H3PO4 and CH3COOH catalysts were 5800 and 4542 mL/min, respectively.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Ibrahim Gozeten, Kadir Karakas, Yasar Karatas, Mehmet Tunc, Mehmet Gulcan
Summary: This study focuses on the production of hydrogen from sodium borohydride in a methanolysis environment using ruthenium nanoparticles impregnated on a halloysite support material. The newly synthesized nanocatalyst showed excellent activity and reusability in the catalytic methanolysis reaction. The material analysis confirmed the homogeneous distribution of ruthenium nanoparticles on the support material. Kinetic studies were conducted to calculate the kinetic parameters and determine the rate equation for hydrogen production.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Inorganic & Nuclear
Aysel Kanturk Figen
Summary: The study focused on continuous hydrogen production from sodium borohydride through methanolytic dehydrogenation, achieving continuous H-2 production using semi-continuous regimes. Batch catalytic hydrogen generation profiles were examined and a figure of merit (FOM) was used for comparative analysis of catalysts' performance. The semi-continuous regime resulted in stable hydrogen production for almost 2.6 hours, with a production rate of 0.94 Lh(-1) from Co-O-B catalyzed methanolytic dehydrogenation of NaBH4.
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
Chemistry, Physical
Samikannu Prabu, Kung-Yuh Chiang
Summary: Sulfur, nitrogen-codoped highly porous carbon nanostructures are used as efficient components for hydrogen generation. The waste coffee grounds are carbonized and activated to produce hierarchically SN doped porous carbon nanostructures. Pd-Co3O4 nanoparticles are anchored onto SN-codoped carbon nanosheets. An effective method for optimization of the Pd-Co3O4/SN-CNS-600 catalytic efficiency is proposed. The catalyst exhibits excellent catalytic activity for NaBH4 catalytic methanolysis at room temperature with a high hydrogen generation rate.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Agricultural Engineering
Cafer Saka, Asim Balbay
Summary: Metal-free carbon catalysts doped with nitrogen and oxygen showed excellent catalytic performance in the NaBH4 methanolysis reaction. With high hydrogen production rate and relatively low activation energy, this catalyst has promising potential for hydrogen generation applications.
BIOMASS & BIOENERGY
(2021)
Article
Chemistry, Physical
Cafer Saka
Summary: A metal-free catalyst was successfully synthesized by modifying carbon nitride with EDTA and protonating the obtained sample. The catalyst was used for hydrogen production from methanolysis of sodium borohydride. The effects of NaBH4 concentration, catalyst amount, temperature, and catalyst reusability were investigated.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Engineering, Electrical & Electronic
Sefika Kaya, Ceren Saka, Aykut Caglar, Mustafa Kaya, Hilal Kivrak
Summary: In this study, Cd-, Te-, Se-, and S-doped titanium dioxide catalysts were prepared via impregnation method. The hydrogen generation performances of these catalysts from NaBH4 under UV illumination and in the dark were investigated. The results showed that the TiO2 catalyst doped with 0.1% Cd had the highest initial hydrogen generation rate under UV illumination.
JOURNAL OF ELECTRONIC MATERIALS
(2023)
Article
Energy & Fuels
Saliha Ozarslan, M. Rasit Atelge, Mustafa Kaya, Sebahattin Unalan
Summary: In this study, a catalyst produced from tea factory waste was utilized for hydrogen production by methanolysis of sodium borohydride. This dual-function material acted as both catalyst and supercapacitor, showing promising results for hydrogen generation. The catalyst was synthesized by treating the waste with acetic acid, leading to efficient hydrogen generation and resembling supercapacitor curves in literature.
Article
Chemistry, Physical
Cafer Saka, Asim Balbay
Summary: Metal-free catalysts were produced from apricot kernel shells for efficient H-2 generation from NaBH4 methanolysis. The catalysts were activated through a two-step process and characterized for their structure and properties. The results showed that the metal-free catalyst exhibited a high hydrogen production rate and low activation energy.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Multidisciplinary
Jun Hu, Gang Kong, Yanbin Zhu, Chunshan Che
Summary: A novel method for ultrafast chemical reduction of graphene oxide at room temperature using NaBH4, Na2MoO4, and HCl was developed in this study, resulting in rGO with higher reduction degree compared to rGO synthesized solely by NaBH4 at high temperature. The rGO electrode based on this reducing method exhibited a superior specific capacitance, making it suitable for supercapacitors.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Physical
Ceren Saka, Derya Yildiz, Sefika Kaya, Aykut Caglar, Dilarasu Elitok, Elif Yayli, Mustafa Kaya, Rasit Atelge, Hilal Kivrak
Summary: In this study, activated carbon is prepared from defatted hazelnut bagasse and its catalytic activities for NaBH4 methanolysis and electrooxidation are evaluated. The material characterization results show that the prepared activated carbons are successful. The N2 adsorption-desorption results reveal that FH3-500 activated carbon has the highest BET surface area, total pore volume, and micropore volume. Additionally, FH3-500 activated carbon catalyst exhibits the highest initial hydrogen production rate and FH2-500 activated carbon shows the highest electrocatalytic activity and stability for sodium borohydride electrooxidation.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Energy & Fuels
Cafer Saka
Summary: A hybrid g-C3N4-SiO2-N composite was successfully produced using calcination and hydrothermal methods. The composite catalyst showed excellent catalytic performance in the H2 production reaction from NaBH4 methanolysis, with a high hydrogen generation rate and good durability.
Article
Thermodynamics
Jae Seon Koh, Do Hoon Kim, Se Hyeok Lee, Min Soo Kim
Summary: The aim of this study was to produce sufficient hydrogen for high-power fuel cell applications through acid-accelerated hydrolysis of sodium borohydride (SBH) with liquid water. The experimental results showed that the conversion of SBH was >= 95%, and a maximum of 6.71 wt% gravimetric hydrogen density was achieved. It was also found that the rate of hydrogen generation could be controlled through the feed injection rate, and the reactant temperature and excess stoichiometric number had significant effects on the hydrogen production.
ENERGY CONVERSION AND MANAGEMENT
(2023)
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
Chemistry, Physical
Cafer Saka, Asim Balbay
Summary: For the first time, phosphoric acid and acetic acid catalysts were used for efficient hydrogen production from sodium borohydride ethylene glycolysis reaction. The experimental results showed that the presence of water negatively affects H-2 production. The hydrogen generation rate obtained with H3PO4 and CH3COOH catalysts were 5800 and 4542 mL/min, respectively.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
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)