@article{MTMT:34823133,
	title = {Enhanced Photocatalytic and Filtration Performance of TiO2-Ag Composite-Coated Membrane Used for the Separation of Oil Emulsions},
	url = {https://m2.mtmt.hu/api/publication/34823133},
	author = {Fazekas, Ákos Ferenc and Gyulavári, Tamás and Ágoston, Áron and Janovák, László and Heszlerné Kopniczky, Judit and László, Zsuzsanna and Veréb, Gábor},
	doi = {10.3390/separations11040112},
	journal-iso = {SEPARATIONS},
	journal = {SEPARATIONS},
	volume = {11},
	unique-id = {34823133},
	issn = {2297-8739},
	abstract = {Polyvinylidene fluoride (PVDF) membranes were coated with TiO2 and TiO2-Ag to enhance their efficiency for oil-in-water emulsion separation. The photocatalytic activities of the two modified membranes and their filtration performances were compared in detail. The significantly enhanced photocatalytic activity of the TiO2-Ag composite was proved using a methyl orange (MO) solution (c = 10−5 M) and a crude oil emulsion (c = 50 mg·L−1). The TiO2-Ag-coated membrane reduced the MO concentration by 87%, whereas the TiO2-modified membrane reached only a 46% decomposition. The photocatalytic reduction in the chemical oxygen demand of the emulsion was also ~50% higher using the TiO2-Ag-coated membrane compared to that of the TiO2-coated membrane. The photoluminescence measurements demonstrated a reduced electron/hole recombination, achieved by the Ag nanoparticle addition (TiO2-Ag), which also explained the enhanced photocatalytic activity. A significant improvement in the oil separation performance with the TiO2-Ag-coated membrane was also demonstrated: a substantial increase in the flux and flux recovery ratio (up to 92.4%) was achieved, together with a notable reduction in the flux decay ratio and the irreversible filtration resistance. Furthermore, the purification efficiency was also enhanced (achieving 98.5% and 99.9% COD and turbidity reductions, respectively). Contact angle, zeta potential, scanning electron microscopy (SEM), and atomic force microscopy (AFM) measurements were carried out to explain the results. SEM and AFM images revealed that on the TiO2-Ag-coated membrane, a less aggregated, more continuous, homogeneous, and smoother nanolayer was formed due to the ~50% more negative zeta potential of the TiO2-Ag nanocomposite compared to that of the TiO2. In summary, via Ag addition, a sufficiently hydrophilic, beneficially negatively charged, and homogeneous TiO2-Ag-coated PVDF membrane surface was achieved, which resulted in the presented advantageous filtration properties beyond the photocatalytic activity enhancement.},
	year = {2024},
	eissn = {2297-8739},
	pages = {112},
	orcid-numbers = {Gyulavári, Tamás/0000-0001-6103-6689; Janovák, László/0000-0002-2066-319X; Veréb, Gábor/0000-0001-9642-1851}
}

@misc{MTMT:34409056,
	title = {Titanium dioxide hollow spheres for water treatment utilizing enhanced light trapping capability},
	url = {https://m2.mtmt.hu/api/publication/34409056},
	author = {Gyulavári, Tamás and Kata, Kovács and Zoltán, Kovács and Veréb, Gábor and Hernádi, Klára and Pap, Zsolt},
	unique-id = {34409056},
	year = {2023},
	orcid-numbers = {Gyulavári, Tamás/0000-0001-6103-6689; Veréb, Gábor/0000-0001-9642-1851; Hernádi, Klára/0000-0001-9419-689X; Pap, Zsolt/0000-0002-8049-0809}
}

@CONFERENCE{MTMT:34407490,
	title = {Development of TiO2 and TiO2/CNT nanocomposite blended and grafted PVDF membranes used for membrane separation of oil emulsions},
	url = {https://m2.mtmt.hu/api/publication/34407490},
	author = {Miklós, Tímea and Gyulavári, Tamás and Hodúr, Cecilia and Hernádi, Klára and László, Zsuzsanna and Veréb, Gábor},
	booktitle = {XXIX. Nemzetközi Vegyészkonferencia / 29th International Conference on Chemistry},
	unique-id = {34407490},
	year = {2023},
	pages = {1-1},
	orcid-numbers = {Gyulavári, Tamás/0000-0001-6103-6689; Hodúr, Cecilia/0000-0002-2028-6304; Hernádi, Klára/0000-0001-9419-689X; Veréb, Gábor/0000-0001-9642-1851}
}

@CONFERENCE{MTMT:34407456,
	title = {Effects of oil composition and CNT functionalizaton on the membrane filtration of oily wastewaters with TiO2/(f)CNT composite-coated PVDF membranes},
	url = {https://m2.mtmt.hu/api/publication/34407456},
	author = {Fazekas, Ákos Ferenc and Gyulavári, Tamás and Pap, Zsolt and Bodor, Attila and Laczi, Krisztián and Perei, Katalin and Nyergesné Illés, Erzsébet and László, Zsuzsanna and Veréb, Gábor},
	booktitle = {XXIX. Nemzetközi Vegyészkonferencia / 29th International Conference on Chemistry},
	unique-id = {34407456},
	year = {2023},
	pages = {1-1},
	orcid-numbers = {Gyulavári, Tamás/0000-0001-6103-6689; Pap, Zsolt/0000-0002-8049-0809; Laczi, Krisztián/0000-0002-9399-7406; Perei, Katalin/0000-0001-8989-2284; Nyergesné Illés, Erzsébet/0000-0002-2901-9616; Veréb, Gábor/0000-0001-9642-1851}
}

@article{MTMT:34166716,
	title = {Effects of Different TiO2/CNT Coatings of PVDF Membranes on the Filtration of Oil-Contaminated Wastewaters},
	url = {https://m2.mtmt.hu/api/publication/34166716},
	author = {Fazekas, Ákos Ferenc and Gyulavári, Tamás and Pap, Zsolt and Bodor, Attila and Laczi, Krisztián and Perei, Katalin and Nyergesné Illés, Erzsébet and László, Zsuzsanna and Veréb, Gábor},
	doi = {10.3390/membranes13100812},
	journal-iso = {MEMBRANES-BASEL},
	journal = {MEMBRANES (BASEL)},
	volume = {13},
	unique-id = {34166716},
	abstract = {Six different TiO2/CNT nanocomposite-coated polyvinylidene-fluoride (PVDF) microfilter membranes (including –OH or/and –COOH functionalized CNTs) were evaluated in terms of their performance in filtering oil-in-water emulsions. In the early stages of filtration, until reaching a volume reduction ratio (VRR) of ~1.5, the membranes coated with functionalized CNT-containing composites provided significantly higher fluxes than the non-functionalized ones, proving the beneficial effect of the surface modifications of the CNTs. Additionally, until the end of the filtration experiments (VRR = 5), notable flux enhancements were achieved with both TiO2 (~50%) and TiO2/CNT-coated membranes (up to ~300%), compared to the uncoated membrane. The irreversible filtration resistances of the membranes indicated that both the hydrophilicity and surface charge (zeta potential) played a crucial role in membrane fouling. However, a sharp and significant flux decrease (~90% flux reduction ratio) was observed for all membranes until reaching a VRR of 1.1–1.8, which could be attributed to the chemical composition of the oil. Gas chromatography measurements revealed a lack of hydrocarbon derivatives with polar molecular fractions (which can act as natural emulsifiers), resulting in significant coalescent ability (and less stable emulsion). Therefore, this led to a more compact cake layer formation on the surface of the membranes (compared to a previous study). It was also demonstrated that all membranes had excellent purification efficiency (97–99.8%) regarding the turbidity, but the effectiveness of the chemical oxygen demand reduction was slightly lower, ranging from 93.7% to 98%.},
	year = {2023},
	eissn = {2077-0375},
	orcid-numbers = {Gyulavári, Tamás/0000-0001-6103-6689; Pap, Zsolt/0000-0002-8049-0809; Laczi, Krisztián/0000-0002-9399-7406; Perei, Katalin/0000-0001-8989-2284; Nyergesné Illés, Erzsébet/0000-0002-2901-9616; Veréb, Gábor/0000-0001-9642-1851}
}

@article{MTMT:34059475,
	title = {Investigation of Photocatalytic PVDF Membranes Containing Inorganic Nanoparticles for Model Dairy Wastewater Treatment},
	url = {https://m2.mtmt.hu/api/publication/34059475},
	author = {Sisay, Elias Jigar and Fazekas, Ákos Ferenc and Gyulavári, Tamás and Heszlerné Kopniczky, Judit and Hopp, Béla and Veréb, Gábor and László, Zsuzsanna},
	doi = {10.3390/membranes13070656},
	journal-iso = {MEMBRANES-BASEL},
	journal = {MEMBRANES (BASEL)},
	volume = {13},
	unique-id = {34059475},
	abstract = {Membrane separation processes are promising methods for wastewater treatment. Membrane fouling limits their wider use; however, this may be mitigated using photocatalytic composite materials for membrane preparation. This study aimed to investigate photocatalytic polyvinylidene fluoride (PVDF)-based nanocomposite membranes for treating model dairy wastewater containing bovine serum albumin (BSA). Membranes were fabricated via physical coating (with TiO2, and/or carbon nanotubes, and/or BiVO4) and blending (with TiO2). Another objective of this study was to compare membranes of identical compositions fabricated using different techniques, and to examine how various TiO2 concentrations affect the antifouling and cleaning performances of the blended membranes. Filtration experiments were performed using a dead-end cell. Filtration resistances, BSA rejection, and photocatalytic cleanability (characterized by flux recovery ratio (FRR)) were measured. The surface characteristics (SEM, EDX), roughness (measured by atomic force microscopy, AFM), wettability (contact angle measurements), and zeta potential of the membranes were also examined. Coated PVDF membranes showed higher hydrophilicity than the pristine PVDF membrane, as evidenced by a decreased contact angle, but the higher hydrophilicity did not result in higher fluxes, unlike the case of blended membranes. The increased surface roughness resulted in increased reversible fouling, but decreased BSA retention. Furthermore, the TiO2-coated membranes had a better flux recovery ratio (FRR, 97%) than the TiO2-blended membranes (35%). However, the TiO2-coated membrane had larger total filtration resistances and a lower water flux than the commercial pristine PVDF membrane and TiO2-blended membrane, which may be due to pore blockage or an additional coating layer formed by the nanoparticles. The BSA rejection of the TiO2-coated membrane was lower than that of the commercial pristine PVDF membrane. In contrast, the TiO2-blended membranes showed lower resistance than the pristine PVDF membrane, and exhibited better antifouling performance, superior flux, and comparable BSA rejection. Increasing the TiO2 content of the TiO2-blended membranes (from 1 to 2.5%) resulted in increased antifouling and comparable BSA rejection (more than 95%). However, the effect of TiO2 concentration on flux recovery was negligible.},
	year = {2023},
	eissn = {2077-0375},
	orcid-numbers = {Gyulavári, Tamás/0000-0001-6103-6689; Hopp, Béla/0000-0002-4272-7721; Veréb, Gábor/0000-0001-9642-1851}
}

@article{MTMT:34039621,
	title = {Titán-dioxid fotokatalizátorok fotokatalitikus aktivitásának növelése},
	url = {https://m2.mtmt.hu/api/publication/34039621},
	author = {Gyulavári, Tamás and Veréb, Gábor and Pap, Zsolt and Hernádi, Klára},
	doi = {10.24100/MKF.2023.01.39},
	journal-iso = {MAGY KÉM FOLY KÉM KÖZL},
	journal = {MAGYAR KÉMIAI FOLYÓIRAT - KÉMIAI KÖZLEMÉNYEK (1997-)},
	volume = {129},
	unique-id = {34039621},
	issn = {1418-9933},
	year = {2023},
	eissn = {1418-8600},
	pages = {39-44},
	orcid-numbers = {Gyulavári, Tamás/0000-0001-6103-6689; Veréb, Gábor/0000-0001-9642-1851; Pap, Zsolt/0000-0002-8049-0809; Hernádi, Klára/0000-0001-9419-689X}
}

@article{MTMT:33709488,
	title = {Effect of Urea as a Shape-Controlling Agent on the Properties of Bismuth Oxybromides},
	url = {https://m2.mtmt.hu/api/publication/33709488},
	author = {Márta, Viktória and Pap, Zsolt and Bárdos, Enikő and Gyulavári, Tamás and Veréb, Gábor and Hernádi, Klára},
	doi = {10.3390/catal13030616},
	journal-iso = {CATALYSTS},
	journal = {CATALYSTS},
	volume = {13},
	unique-id = {33709488},
	abstract = {Bismuth oxybromides were prepared via a solvothermal method by applying different urea amounts during synthesis. The effects of the urea ratio on the morpho–structural properties and photocatalytic activity of the samples were investigated. X-ray diffraction, diffuse reflectance spectroscopy, infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and surface tension measurements were carried out to characterize the samples. Their photoactivity was evaluated by the photocatalytic degradation of rhodamine B and ibuprofen under UV and visible light irradiations. The urea ratio notably influenced morphology, particle size distribution, and photoactivity. However, it only had a limited effect on the crystalline composition, primary crystallite size, and band gap of bismuth oxybromides. The formation of Bi-based complexes and degraded urea-based products were observed, which were deduced to influence band gap energies and hence, photoactivity. Predominantly, samples prepared at low urea ratios proved to be the best for both rhodamine B and ibuprofen degradations under both irradiations.},
	year = {2023},
	eissn = {2073-4344},
	orcid-numbers = {Pap, Zsolt/0000-0002-8049-0809; Gyulavári, Tamás/0000-0001-6103-6689; Veréb, Gábor/0000-0001-9642-1851; Hernádi, Klára/0000-0001-9419-689X}
}

@article{MTMT:33641282,
	title = {Application of BiVO4/TiO2/CNT Composite Photocatalysts for Membrane Fouling Control and Photocatalytic Membrane Regeneration during Dairy Wastewater Treatment},
	url = {https://m2.mtmt.hu/api/publication/33641282},
	author = {Sisay, Elias Jigar and Kertész, Szabolcs and Fazekas, Ákos Ferenc and Jákói, Zoltán Péter and Kedves, Endre-Zsolt and Gyulavári, Tamás and Ágoston, Áron and Veréb, Gábor and László, Zsuzsanna},
	doi = {10.3390/catal13020315},
	journal-iso = {CATALYSTS},
	journal = {CATALYSTS},
	volume = {13},
	unique-id = {33641282},
	abstract = {This study aimed to investigate the performance of composite photocatalytic membranes fabricated by incorporating multiple nanoparticles (TiO2, carbon nanotubes, BiVO4) into polyvinylidene fluoride membrane material for real dairy wastewater treatment. The composite photocatalytic membranes exhibited superior antifouling behavior, lower filtration resistance, better flux, and higher flux recovery ratio than the pristine membrane. Salinity, pH, and lactose concentration are determinant factors that affect filtration resistance and rejection performance during the ultrafiltration of dairy wastewater. Generally, higher irreversible and total resistances and slightly lower chemical oxygen demand (COD) rejections were found at higher salinity (expressed by electric conductivity values of >4 mS/cm) than lower salinity (<4 mS/cm) levels. The presence of lactose in dairy wastewater increased irreversible resistance and severely reduced COD rejection during ultrafiltration due to the ability of lactose to pass through the membranes. It was ascertained that membranes require further treatment after filtrating such wastewater. Lower resistances and slightly better COD rejections were observed at pH 7.5 and pH 9.5 compared to those observed at pH 4. Photocatalytic membranes fouled during the ultrafiltration of real dairy wastewater were regenerated by visible light irradiation. The membrane containing all constituents (i.e., TiO2, carbon nanotubes, and BiVO4) showed the best regeneration performance, exceeding that of the pristine membrane by 30%.},
	year = {2023},
	eissn = {2073-4344},
	orcid-numbers = {Sisay, Elias Jigar/0000-0001-7622-0083; Kertész, Szabolcs/0000-0001-9760-3008; Jákói, Zoltán Péter/0000-0002-1502-1029; Gyulavári, Tamás/0000-0001-6103-6689; Ágoston, Áron/0000-0001-9280-3406; Veréb, Gábor/0000-0001-9642-1851}
}

@article{MTMT:33636061,
	title = {Outstanding Separation Performance of Oil-in-Water Emulsions with TiO2/CNT Nanocomposite-Modified PVDF Membranes},
	url = {https://m2.mtmt.hu/api/publication/33636061},
	author = {Fekete, Laura and Fazekas, Ákos Ferenc and Hodúr, Cecilia and László, Zsuzsanna and Ágoston, Áron and Janovák, László and Gyulavári, Tamás and Pap, Zsolt and Hernádi, Klára and Veréb, Gábor},
	doi = {10.3390/membranes13020209},
	journal-iso = {MEMBRANES-BASEL},
	journal = {MEMBRANES (BASEL)},
	volume = {13},
	unique-id = {33636061},
	abstract = {Membrane filtration is an effective technique for separating micro- and nano-sized oil droplets from harmful oil-contaminated waters produced by numerous industrial activities. However, significant flux reduction discourages the extensive application of this technology; therefore, developing antifouling membranes is necessary. For this purpose, various titanium dioxide/carbon nanotube (TiO2/CNT) nanocomposites (containing 1, 2, and 5 wt.% multi-walled CNTs) were used for the modification of polyvinylidene fluoride (PVDF) ultrafilter (250 kDa) membrane surfaces. The effects of surface modifications were compared in relation to the flux, the filtration resistance, the flux recovery ratio, and the purification efficiency. TiO2/CNT2% composite modification reduced both irreversible and total filtration resistances the most during the filtration of 100 ppm oil emulsions. The fluxes were approximately 4–7 times higher compared to the unmodified PVDF membrane, depending on the used transmembrane pressure (510, 900, and 1340 L/m2h fluxes were measured at 0.1, 0.2, and 0.3 MPa pressures, respectively). Moreover, the flux recovery ratio (up to 68%) and the purification efficiency (95.1–99.8%) were also significantly higher because of the surface modification, and the beneficial effects were more dominant at higher transmembrane pressures. TiO2/CNT2% nanocomposites are promising to be applied to modify membranes used for oil–water separation and achieve outstanding flux, cleanability, and purification efficiency.},
	keywords = {TIO2; NANOCOMPOSITE; carbon nanotube; Membrane filtration; Microfiltration; MWCNT; nano-TiO2; PVDF; Oil emulsion; enhanced flux; reduced resistance; pressure-dependent effects},
	year = {2023},
	eissn = {2077-0375},
	orcid-numbers = {Hodúr, Cecilia/0000-0002-2028-6304; Janovák, László/0000-0002-2066-319X; Gyulavári, Tamás/0000-0001-6103-6689; Pap, Zsolt/0000-0002-8049-0809; Hernádi, Klára/0000-0001-9419-689X; Veréb, Gábor/0000-0001-9642-1851}
}