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Öğe A New Design to Enhance the Enzyme Activities: Investigation of L-Asparaginase Catalytic Performance by IMAC Effect on g-C3N4 Nanolayers(Springer Link, 2024) Sert, Buse; Acet, Ömür; Noma, Samir Abbas Ali; Osman, Bilgen; Odabaşı, Mehmet; Ocakoğlu, KasımRecently, graphite carbon nitride (g-C3N4) has come to the fore as a new material with its carbon-based two-dimensional structure, simple preparation procedure, and excellent physicochemical stability properties. This study aims to investigate the activity and kinetic studies of the L-asparaginase enzyme via immobilized metal ion affinity chromatography (IMAC) process of g-C3N4 nanolayers. Firstly, g-C3N4 nanolayers were synthetized and Ni2+ ions were binded their surfaces. The synthesized samples were investigated by SEM, ICP-MS, XRD, and FTIR. The highest L-ASNase adsorption on Ni2+-g-C3N4 nanostructures was 444.1 mg/g, at 3 mg/mL L-ASNase concentration. Optimal medium conditions for L-ASNase adsorption occurred at pH 8.0 and 25 °C. The immobilized enzyme showed improved stability relating to the soluble enzyme in extreme situations. On the other hand, the storage stability and reusability of the immobilized enzyme were found to be approximately 64 and 53% of the original activity after 29 days at room temperature and 10 cycles, respectively. From the Michaelis–Menten constants Km and Vmax, both of them decreased after immobilization compare to the free one. The obtained outcomes showed that the g-C3N4 is a suitable matrix for L-asparaginase immobilization with ideal catalytic efficiency and improved stability.Öğe Bor nitrür kuantum nokta-grafen hidrojel kompozitinin süper kapasitör uygulaması(2024) Sert, Buse; Harputlu, ErsanBu çalışmada süperkapasitörler için kullanılacak yeni bir elektrot malzemesi olan bor nitrür kuantum nokta (BNKN) / indirgenmiş grafen oksit (rGO) hibrit yapısının sentezini ve elektrokimyasal uygulamalarına yer verilmiştir. BNKN’nin, grafen oksit (GO) ile aynı kristal yapıya sahip olması ve bunun sonucunda BNKN@rGO hibrit yapısının çok iyi elektriksel özellik gösteriyor olması tercih edilme sebeplerindendir. Hekzagonal bor nitrür (h-BN) nanoyapı tabanlı hibrit malzeme olan BNKN, termal kararlılıkları ve elektriksel iletkenlikleri sebepleriyle son yıllardaki çalışmalarda karşımıza çıkarken, grafen ise geniş spesifik yüzey alanına sahip olduğu için süperkapasitör çalışmalarında sıklıkla tercih edilmektedir. Ayrıca, grafenin kapasitans değerini geliştirmek için bu yapıya farklı nanomalzemeler eklenmesinin ana sebebi karbon malzemelerin elektron verici özelliklerinin geliştirilmesidir. Bundan dolayı, süperkapasitörlerde kullanılacak BNKN@rGO hibrit elektrotunun elektrokimyasal aktiviteyi arttıracağı düşünülerek spesifik kapasitans değeri ölçülmüştür. Elektrokimyasal çalışmalar sonucunda, BNKN@rGOH hibrit yapısının 5 mvs-1 tarama hızında 207.5 F/g yüksek kapasitans değeri elde edilmiştir. Ayrıca 1.000 döngüde %88.9’luk döngüsel stabilite performansı sergilemiştir.Öğe Combustion Characteristics of r-GO/g-C3N4/LaFeO3 Nanohybrids Loaded Fuel Droplets(Taylor and Francis Ltd., 2023) Küçükosman, Rıdvan; Değirmenci, Hüseyin; Sert, Buse; Yontar, Ahmet Alper; Harputlu, Ersan; Ocakoğlu, KasımGraphene oxide (GO), reduced graphene oxide (r-GO) and graphitic carbon nitride (g-C3N4) are two-dimensional carbon-based nanosheets that show promise in reducing emissions with their superior catalytic activity in capturing species such as NOx and CO2 thanks to their oxygen- based functional groups and active edges on their surfaces. These active surfaces also provide a scheme for the substitution of materials with high calorific value or high catalytic activity for combustion. This study focuses on the fabrication of functional nanohybrid structures customized for combustion with LaFeO3 metal oxide nanoparticles substituted on these nanosheets and their effect on the combustion behavior of gaso-line. The fabrication of r-GO/g-C3N4/LaFeO3 nanohybrid structures was carried out by a two-step hydrothermal method. The structural character-izations of the samples were confirmed by SEM and XRD analyses and their chemical states were confirmed by Raman and XPS techniques. Combustion experiments were carried out by droplet scale combustion of gasoline-based nanofuel droplets containing dilute (0.2 wt.%) and high (0.7 wt.%) concentrations of GO, r-GO, g-C3N4, g-C3N4/LaFeO3 and r-GO/g- C3N4/LaFeO3 nanoparticles. The experimental process was recorded with a high-speed camera and a thermal camera. The nanofuel droplets con-taining 0.2 wt.% g-C3N4/LaFeO3 nanohybrid structures had the highest maximum flame temperature of 519 K, and the nanofuel droplets con-taining 0.7 wt.% r-GO/g-C3N4/LaFeO3 particles had the highest maximum aggregate temperature of 1177 K. The ignition delay time decreased for all droplets with 0.2 wt.% and 0.7 wt.% particle loadings. At 0.2 wt.% concentration, g-C3N4 doped fuel droplets exhibited the lowest extinction time, while at 0.7 wt.% concentration, the lowest extinction time was measured for r-GO/g-C3N4/LaFeO3 doped fuel droplets. Fuel droplets containing g-C3N4 particles had the highest burning rate and were the fastest extinguishing fuel droplets in the electric field. In this study, it has been demonstrated that the combustion rate and energy value of hydro-carbon fuels can be increased and soot formation can be reduced at the same time with the new generation of graphene-based functional mate-rials to be created, and thus, many combustion problems can be solved simultaneously with these functional particles.Öğe Development of a Cr2AlC MAX phase/g-C3N4 composite-based electrochemical sensor for accurate cabotegravir determination in pharmaceutical and biological samples(Springer, 2024) Bouali, Wiem; Genc, Asena Ayse; Erk, Nevin; Kaya, Gul; Sert, Buse; Ocakoğlu, KasımA highly sensitive electrochemical sensor is reported that employs a modified electrode for the precise measurement of cabotegravir, a potent anti-HIV drug. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) were utilized for this purpose. Electrode modification involved the immobilization of Cr2AlC MAX phase/g-C3N4 onto a glassy carbon electrode (GCE) to enhance its electrocatalytic activity and selectivity for cabotegravir detection. Under the optimal experimental conditions, the working potential (vs. Ag/AgCl) was to 0.93 V. The developed sensor exhibited a good linear relationship in the range 0.05 µM to 9.34 µM with a low limit of detection of 4.33 nM, signifying its exceptional sensitivity. Additionally, it demonstrated successful cabotegravir detection in pharmaceutical formulations and biological samples, achieving an RSD below 3.0%. The recoveries fell within the range 97.7 to 102%, confirming the sensor's potential for real-sample applications. This innovative electrochemical sensor represents a significant advancement, providing a simple, reliable, and sensitive tool for the accurate measurement of cabotegravir. Its potential applications include optimizing drug dosages, monitoring treatment responses, and supporting the development of cabotegravir-based pharmaceutical products, thereby contributing to advancements in HIV therapy and prevention strategies.Öğe Development of antimicrobial nanocomposite scaffolds via loading CZTSe quantum dots for wound dressing applications(Iop Publishing Ltd, 2022) Ceylan, Seda; Sert, Buse; Yurt, Fatma; Tuncel, Ayca; Ozturk, Ismail; Demir, Didem; Ocakoglu, KasimThe antimicrobial properties of scaffolds designed for use in wound healing are accepted as an important factor in the healing process to accelerate the wound healing process without causing inflammation. For this purpose, chitosan-polyvinyl alcohol composite membranes loaded with Cu2ZnSnSe4 quantum dots (CZTSe QDs) as an antibacterial and cytocompatible biomaterial to regulate the wound healing process were produced. CZTSe QDs particles were synthesized under hydrothermal conditions. Polymer-based nanocomposites with different concentrations of the synthesized nanoparticles were produced by the solvent casting method. After detailed physicochemical and morphological characterizations of CZTSe QDs and composite membranes, antibacterial activities and cell viability were extensively investigated against gram-positive and gram-negative bacterial and yeast strains, and L929 mouse fibroblast cells lines, respectively. The results show that the preparation of composite scaffolds at a QDs concentration of 3.3% by weight has the best antimicrobial activity. Composite scaffold membranes, which can be obtained as a result of an easy production process, are thought to have great potential applications in tissue engineering as wound dressing material due to their high mechanical properties, wettability, strong antibacterial properties and non-toxicity.Öğe Evaluating the simultaneous electrochemical determination of antineoplastic drugs using LaNiO3/g-C3N4@RGH nanocomposite material(Elsevier, 2024) Bouali, Wiem; Erk, Nevin; Sert, Buse; Harputlu, ErsanA novel electrochemical sensor based on LaNiO3/g-C3N4@RGH nanocomposite material was developed to simultaneously determine Ribociclib (RIBO) and Alpelisib (ALPE). Ribociclib and Alpelisib are vital anticancer medications used in the treatment of advanced breast cancer. The sensor exhibited excellent electrocatalytic activity towards the oxidation of RIBO and ALPE, enabling their simultaneous detection. The fabricated sensor was characterized using various techniques, including energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS), which confirmed the successful synthesis of the LaNiO3/g-C3N4@RGH composite material. Electrochemical characterization revealed enhanced conductivity and lower resistance of the modified electrode compared to the bare electrode. The developed sensor exhibited high repeatability, reproducibility, stability, and selectivity toward RIBO detection. Furthermore, the sensor displayed high sensitivity with low detection limits of 0.88 nM for RIBO and 6.1 nM for ALPE, and linear ranges of 0.05–6.2 ?M and 0.5–6.5 ?M, respectively. The proposed electrochemical sensor offers a promising approach for simultaneously determining RIBO and ALPE in pharmaceutical formulations and biological samples with recovery data of 98.7–102.0 %, providing a valuable tool for anticancer drug analysis and clinical research.Öğe Grafitik karbon nitrür ve bor nitrür içeren kompozit yapıların hazırlanması; çevre ve enerji uygulamaları(2022) Sert, BuseYarı iletken nanokompozit malzemeler son yıllarda çevresel iyile?tirme ve enerji uygulamaları için yoğun ilgi görmektedir. Bu tez çalı?ması kapsamında nanamalzeme katkılı membranlar ve süperkapasitörler üretilmi?tir. Yüksek termal stabilitesi ve iyi dağılabilirlik, kimyasal kararlılık, elektriksel yalıtım özellikleri ve toksik olmamaları sebebiyle grafitik karbon nitrür (g-C3N4) ve bor nitrür kuantum noktalar (BNKN) bu uygulamalarda nanokompozit malzemelerin esas bile?enleri olarak kullanılmı?tır. g-C3N4 ve BNKN üretimi sırasıyla sinterleme ve hidrotermal i?lem ile gerçekle?tirilmi?tir. Nanomalzemelerin çevresel uygulamalarında, ağırlıkça % 0.5, % 1.0 ve % 2.0 g-C3N4 veya BNKN içeren polietersülfon (PES) membranlar (gC3N4@PES, BNKN@PES) bir döküm ünitesinde üretilmi?tir. Membranların saf su akı geçirgenlik performansı ile birlikte membran tıkanıklığını önleme ve kirlilik çalı?maları da ara?tırılmı?tır. Hibrit membranların, saf PES membrandan daha iyi temizleme özelliği sergilediği görülmü?tür. Enerji uygulamalarında kullanılmak üzere, g-C3N4 veya BNKN içeren grafen elektrotlar hazırlanmı?tır. Bu kapsamda, farklı miktarlarda alınan g-C3N4 veya BNKN (15 mg / 30 mg / 60 mg), indirgenmi? grafen oksit (rGO) (30 mg) ile hidrotermal i?leme tabii tutularak, süperkapasitör uygulamalarında kullanılabilecek elektrotlar (gC3N4@rGOH ve BNKN@rGOH) hazırlanmı? ve uygun tekniklerle (XRD, SEM, CV, BET, ZETA) karakterize edilmi?tir. Bu hibrit yapılardan üretilen elektrotların spesifik kapasitans değerleri, empedans eğrileri ve ?arj/de?arj performansları elektrokimyasal teknikler ile analiz edilmi?tir. g-C3N4@rGOH (30 mg/15 mg oranlarında) hazırlanan elektrotun 157.4 F g -1 spesifik kapasitans değeri ile en yüksek performansa sahip olduğu bulunmu?tur. E?it oranlarda hazırlanan BNKN@rGOH (30 mg/30 mg oranlarında) ii hibrit yapısından ise 207.25 F g-1 spesifik kapasitans değeri ile en yüksek performansa sahip olduğu bulunmu?tur. Bu tez çalı?masından elde edilen sonuçlara göre; üretilen hibrit yapıların, çevre ve enerji uygulamalarında gelecek vaad ettiği görülmektedir.Öğe Immobilization of Alpha-Amylase onto Ni2+ Attached Carbon Felt: Investigation of Kinetic Parameters from Potato Wastewater(Wiley, 2023) Acet, Ömür; İnanan, Tülden; Öndül Koç, Eda; Sert, Buse; Önal Acet, Burcu; Odabaşı, Mehmet; Ocakoğlu, Kasım; Dizge, Nadir?-amylase is an important enzyme for textile, food, paper, and the pharmaceutical industrial areas. In this study, Ni2+ attached carbon felt structures with nitrogen active site (Ni2+-N-ACF) are produced. The surface morphologies of the N-ACF and Ni2+-N-ACF are investigated by means of scanning electron microscopy (SEM) analysis. Ni2+ ions binding on the N-ACFs are determined by energy dispersive X-ray (EDX) analysis and a graphite furnace atomic absorption spectrometer (AAS). The effect of pH, ionic strength, initial ?-amylase concentration, and temperature parameters is investigated for ?-amylase immobilization on Ni2+-N-ACF structures. In addition, pH and temperature effect on the activities of the free and the immobilized amylase, kinetic parameters, storage, and operational stabilities are made. Lastly, starch degradation in potato waste water is tested on Ni2+-N-ACF. The obtained results show that ?-amylase immobilized Ni2+-N-ACF can be used for starch degradation on an industrial scale.Öğe Improvement in performance of g-C3N4 nanosheets blended PES ultrafiltration membranes including biological properties(Elsevier, 2021) Sert, Buse; Ozay, Yasin; Harputlu, Ersan; Ozdemir, Sadin; Yalcin, M. Serkan; Ocakoglu, Kasim; Dizge, NadirThis study aims to investigate the modification of polyethersulphone (PES) membrane with graphitic carbon nitride (g-C3N4) nanosheets for improving the antifouling and separation performance. The nanocomposite membranes were fabricated with blending of different g-C3N4 nanosheets (0.50, 1.00, and 2.00 wt%) into PES and they were synthesized by the phase inversion method. The fabricated g-C3N4 nanosheets and composite membranes were analyzed for their morphology. Scanning electron microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) mapping were used to detect the distribution of g-C3N4 nanosheets on membrane surface, whereas surface roughness of membrane was evaluated by atomic force microscopy (AFM). The composite membrane surface was found to be hydrophilic (67.54 degrees), while the water flux of the composite membrane was found to be 254.8 L/m(2)/h for 2.00 wt% g-C3N4/PES membrane. The bovine serum albumin (BSA) separation tests indicated that the composite membrane supplied 98.5% BSA rejection ratio. Moreover, a significant improvement in antifouling characteristics were verified from BSA filtration experiments. g-C3N4 was also investigated for some of its biological properties such as antioxidant, antimicrobial, DNA cleavage, biofilm inhibition, and bacterial viability effect. g-C3N4 showed good free radical scavenging activity and moderate chelating activity at 500 mg/L. It was also determined that single-strand DNA cleavage activities occurred at all tested concentrations. g-C3N4 exhibited significant antibiofilm activity and inhibitory effects on E. coli vitality as 90.9%, 97.1%, and 98.9% at 250, 500, and 1000 mg/L, respectively. This study provides a simple and useful guideline to create a UF membrane resistant against organic fouling and expand its practical applications for wastewater treatment.Öğe Influence of silane coating and graphene oxide integration on the magnetothermal Behaviors of La1-xSrxMnO3 nanoparticles(Elsevier, 2025) Sert, Buse; Kaya, Gul; Cicek, Sinem; Harputlu, Ersan; Simsek, Telem; Tekgul, Atakan; Unlu, C. GokhanIn this study, La1-xSrxMnO3 (x = 0.27, 0.3, 0.33) magnetic nanoparticles (MNPs) were synthesized and then these nanoparticles synthesized in the core-shell structure were coated with silane for potential magnetic hyperthermia applications. In order to provide support material for the coated magnetic nanoparticles, silane-coated hybrid magnetic nanoparticles were obtained by producing graphene oxide (GO) nanoflakes. The structural and magnetic properties and magnetothermal properties of these structures were investigated. It was observed that the structure of the silane-coated magnetic nanoparticles remained intact and did not show any degradation compared to the uncoated materials. In addition, the highest saturation magnetization (MS) value was observed in the sample doped with x = 0.30. This value indicated that the heating power would be higher than the other doped samples in the specific absorption ratio (SAR) measurements. In this context, the heating amount in the silane-coated samples showed a slight decrease compared to the uncoated samples. Despite the decrease in the SAR values of the integrated samples by incorporating GO into the coated MNPs, it is anticipated that effective results will be obtained for practical applications with the advantage of increasing the thermal conductivity of GO.Öğe Investigating the effect of coating and synthesis parameters on La1-xSrxMnO3 based core-shell magnetic nanoparticles(Elsevier, 2025) Sert, Buse; Kaya, Gul; Tataroglu, Aleyna Akcay; Harputlu, Ersan; Simsek, Telem; Tekguel, Atakan; Unlu, C. GokhanMagnetic nanoparticles are an important class of functional materials that have unique magnetic properties due to their reduced size (<100 nm) and have the potential for use in many fields. In the preparation of magnetic nanoparticles, factors such as intrinsic magnetic properties, surface coating, size and shape of the particles, surface charge and stability are very important. In this regard, carefully determining the synthesis parameters of magnetic nanoparticles and particle coating materials is of critical importance in the application area chosen for the material. In this study, La1-xSrxMnO3 (x = 0.27, 0.30, 0.33) magnetic nanoparticles (MNPs), carbon-coated magnetic nanoparticles in core-shell structure (C@MNP) and their derivatives integrated into graphene oxide (GO-C@MNP) were synthesized and their properties were investigated in detail for their use in possible future application studies. The crystal structure of perovskite compounds with Pbnm symmetry remains unchanged after carbon coating but shrinks in volume due to its amorphous structure. The magnetic behavior of the uncoated and coated materials is almost identical, but the Curie temperature of the compounds shifts to a higher temperature. In the specific absorption ratio (SAR) measurements performed, it was found that the best SAR value for carbon-coated MNPs was 12.9 W/g at x = 0.27. By integrating the MNPs into graphene oxide, heat is easily distributed regionally, and this shows that the structures can be ideal candidates for applications such as hyperthermia, drug carriers, tissue repair, and cellular therapy including cell labeling and targeting. Perovskite-structured manganite materials were selected for their suitability in controlled production, where the Curie temperature can be tuned near the therapeutic temperature by adjusting the doping levels, making them ideal for magnetic hyperthermia applications. In this study, for the first time, the nanoparticle surfaces were coated with carbon, which was chosen not only due to carbon's non-magnetic nature but also because it provides an ideal platform for future combined biomedical applications such as drug delivery systems.Öğe Investigation of the antifouling properties of polyethersulfone ultrafiltration membranes by blending of boron nitride quantum dots(Elsevier, 2021) Sert, Buse; Gonca, Serpil; Ozay, Yasin; Harputlu, Ersan; Ozdemir, Sadin; Ocakoglu, Kasim; Dizge, NadirThis study aims to investigate the modification of polyethersulfone (PES) membrane with boron nitride quantum dots (BNQD) for improving the antifouling performance. The composite membranes were synthesized by blending different amounts of BNQD (0.50, 1.00, and 2.00 wt.%) into PES with the non-solvent induced phase separation (NIPS) method. UV-vis absorption, X-ray diffraction (XRD), and transmission electron microscopy (TEM) were used to characterize BNQD. Moreover, porosity, pore size, contact angle, permeability, bovine serum albumin (BSA) rejection, and antifouling properties were determined for composite membranes. The enhanced biological activity of BNQD was investigated based on antioxidant, antimicrobial, anti-biofilm, bacterial viability inhibition, and DNA cleavage studies. The BNQD showed 19.35 % DPPH radical scavenging activity and 76.45 % ferrous ion chelating activity at 500 mg/L. They also exhibited good chemical nuclease activity at all concentrations. BNQD had moderate antibacterial activity against all tested microorganisms. Biofilm inhibition percentage of BNQD was determined as 82.31 % at 500 mg/L. Cell viability assay demonstrated that the BNQD showed strong cell viability inhibition 99.9 % at the concentration of 1000 mg/L. The porosity increased from 56.83 +/- 1.17%-61.83 +/- 1.17 % while BNQD concentration increased from 0 to 2.00 wt%. Moreover, the hydrophilicity of BNQD nanocomposite membranes also increased from 75.42 +/- 0.56 degrees to 65.34 +/- 0.25 degrees. The mean pore radius is far slightly changed from 16.47 +/- 0.35 nm to 19.16 +/- 0.22 nm. The water flux increased from 133.5 +/- 9.5 L/m(2)/h (for pristine membrane) to 388.6 +/- 18.8 L/m(2)/h (for PES/BNQD 2.00 wt% membrane). BSA flux increased from 38.8 +/- 0.9 L/m(2)/h to 63.2 +/- 2.7 L/m(2)/h up to 1.00 wt% amount of BNQD nanoparticles.Öğe Photothermal and photodynamic responses of core-shell Mo2C@C@Fucoidan nanospheres(Elsevier Science Sa, 2025) Tuncel, Ayca; Sert, Buse; Ozel, Derya; Kaya, Gul; Harputlu, Ersan; Unlu, Cumhur Gokhan; Ocakoglu, KasimMo2C structure, a transition metal carbide, is known for its exceptional properties including high chemical and thermal stability and surface activity. Recently, carbon-modified Mo2C structures have found widespread applications due to their effectiveness. Here, we synthesized pomegranate-like Mo2C@C nanospheres and coated them with poly(allylamine hydrochloride) (PAH) and fucoidan structures. Characterization techniques including FE-SEM, HR-TEM, XRD, XPS, and zeta potential analysis were employed. We investigated the effect of Mo2C@C@Fuc nanospheres by quantitatively evaluating their photothermal conversion efficiency. Under irradiation at wavelengths of 808 nm and 1064 nm with a power intensity of 2 W/cm2, these nanospheres could convert up to 15 % of the incident laser energy into heat, outperforming conventional materials. Stability tests in various physiological pH environments confirmed their durability under NIR irradiation, ensuring operational integrity in biological environments. In addition, they showed significant efficiency in the production of singlet oxygen, making them promising agents for PDT. Biodegradation studies indicated safe degradation after ther- apeutic application, highlighting their environmental and physiological compatibility. Integrating Mo2C@C@- Fuc nanospheres into anticancer strategies combines the advantages of PTT and PDT, promising improved therapeutic outcomes with high biocompatibility.Öğe Preparation of S-Scheme g-C3N4/ZnO Heterojunction Composite for Highly Efficient Photocatalytic Destruction of Refractory Organic Pollutant(Mdpi, 2023) Sert, Buse; Bilici, Zeynep; Ocakoglu, Kasim; Dizge, Nadir; Rad, Tannaz Sadeghi; Khataee, AlirezaIn this study, graphitic carbon nitride (g-C3N4)-based ZnO heterostructure was synthesized using a facile calcination method with urea and zinc nitrate hexahydrate as the initiators. According to the scanning electron microscopic (SEM) images, spherical ZnO particles can be seen along the g-C3N4 nanosheets. Additionally, the X-ray diffraction (XRD) analysis reveals the successful synthesis of the g-C3N4/ZnO. The photocatalytic activity of the synthesized catalyst was tested for the decolorization of crystal violet (CV) as an organic refractory contaminant. The impacts of ZnO molar ratio, catalyst amount, CV concentration, and H2O2 concentration on CV degradation efficiency were investigated. The obtained outcomes conveyed that the ZnO molar ratio in the g-C3N4 played a prominent role in the degradation efficiency, in which the degradation efficiency reached 95.9% in the presence of 0.05 mmol of ZnO and 0.10 g/L of the catalyst in 10 mg/L of CV through 120 min under UV irradiation. Bare g-C3N4 was also tested for dye decolorization, and a 76.4% dye removal efficiency was obtained. The g-C3N4/ZnO was also tested for adsorption, and a 32.3% adsorption efficiency was obtained. Photocatalysis, in comparison to adsorption, had a dominant role in the decolorization of CV. Lastly, the results depicted no significant decrement in the CV degradation efficiency in the presence of the g-C3N4/ZnO photocatalyst after five consecutive runs.Öğe Süperkapasitör performansını artırmak için grafitik karbon nitrür /grafen hibrit yapılarının kullanılması(2022) Sert, Buse; Harputlu, ErsanUygun morfolojiye ve mükemmel iletkenliğe sahip yüksek verimli, düşük maliyetli hibrit nanoyapılar tasarlamak, elektrokimyasal depolama cihazlarında kullanılan elektrotlar için umut vericidir. Bu çalışma, süperkapasitör (SK) uygulamaları için grafitik karbon nitrür (g-C3N4) ve indirgenmiş grafen oksit hidrojel (rGOH) yapılarından oluşan üç boyutlu (3B) hibrit yapının üretimi ve elektrokimyasal çalışmalardan elde edilen sonuçları içermektedir. Bilindiği üzere, süperkapasitörde spesifik kapasitans miktarının artırılması yapıda kullanılan elektrot-elektrolit arasındaki temas yüzeyi ile doğru orantılıdır. Bu yüzden, rGOH yapısının yüksek yüzey alanı ve termal stabiliteye sahip olması, g-C3N4‘ün de süperkapasitörlerde elektrokimyasal aktiviteyi arttırmasından dolayı, mevcut yapılar bir araya getirilerek elde edilen elektrotun spesifik kapasitans değeri ölçülmüştür. Süperkapasitör olarak kullanılacak bu elektrotun üretilmesiyle, yüksek spesifik kapasitans değeri elde edilmiştir. Elektrokimyasal çalışmalar sonucunda, g-C3N4@rGOH hibrit yapısının 5 mVs-1 tarama hızında 157.4 F/g yüksek kapasitans değeri elde edilmiştir. Ayrıca 1000 döngüde %112’lik benzersiz bir döngüsel stabilite performansı sergilemiştir.Öğe Synthesis of PES membranes modified with polyurethane–paraffin wax nanocapsules and performance of bovine serum albumin and humic acid rejection(IWA Publishing, 2023) Sert, Buse; Kaya, Gul; Ozay, Yasin; Alterkaoui, Aya; Ocakoglu, Kasım; Dizge, NadirMembrane fouling is a serious handicap of membrane-based separation, as it reduces permeation flux and hence increases operational and maintenance expenses. Polyurethane–paraffin wax (PU/PW) nanocapsules were integrated into the polyethersulfone membrane to manufacture a composite membrane with higher antifouling and permeability performance against humic acid (HA) and bovine serum albumin (BSA) foulants. All manufactured membranes were characterized by scanning electron microscopy (SEM), scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), and contact angle. The contact angle of the pristine polyethersulfone (PES) membrane was measured 73.40 + 1.32. With the embedding of nanocapsules, the contact angle decreased to 64.55 + 1.23 for PES/PU/PW 2.0 wt%, and the pure water flux of all composite membranes increased when compared to pristine PES. The pristine PES membrane also has shown the lowest steady-state fluxes at 45.84 and 46.59 L/m2 h for BSA and HA, respectively. With the increase of PU/PW nanocapsule ratio from 0.5 to 1.0 wt%, steady-state fluxes increased from 51.96 to 71.61 and from 67.87 to 98.73 L/m2 h, respectively, for BSA and HA. The results depicted that BSA and HA rejection efficiencies of PU/PW nanocapsules blended PES membranes increased when compared to pristine PES membranesÖğe Synthesis, characterization and evaluation of the photochemical properties and photothermal conversion capacities of Mo2CTx-MXene@Fuc nanohybrids(Elsevier Science Sa, 2025) Yurt, Fatma; Tuncel, Ayca; Kaya, Gul; Sert, Buse; Ozel, Derya; Harputlu, Ersan; Unlu, Cumhur GokhanStudies on synthesizing MXene hybrid materials continue in medicine, biomedicine, the environment, electronics, and many other fields. MXenes are very remarkable materials for diagnosis, treatment, and theranostic applications in oncology with their hydrophilic structure, large surface area, and biocompatibility. In this study, MAX phase and Mo2CTx MXene syntheses were first carried out and characterized by XRD and HR-TEM. Then, PAH and fucoidan were coated on the MXene surface, respectively, and characterized by FE-SEM, XPS, and Zeta potential methods. Experiments on Mo2CTx-MXene@Fuc nanohybrids have identified their photothermal conversion capacity and photostability, which are crucial for photothermal therapy applications. After calibration of laser devices at 808 and 1064 nm, the nanohybrids' response to laser exposure was monitored, with temperature changes recorded via a thermal camera. Additionally, the photothermal conversion capacity was deduced from heating and cooling durations, while singlet oxygen production efficiency was evaluated using the 1,3-Diphenylisobenzofuran (DPBF) fluorescent probe. These findings underscore the potential of Mo2CTx-MXene@Fuc nanomaterials in photothermal therapy, particularly their efficiency in converting NIR radiation into therapeutic heat.
