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Your search keyword '"Rodrigues, Liana Alvares"' showing total 167 results
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167 results on '"Rodrigues, Liana Alvares"'

13. Cross-linked cellulose beads as an eco-friendly support for ZnO/SnO2/carbon xerogel hybrid photocatalyst: Exploring the synergy between adsorption and photocatalysis under simulated sunlight

Author

de Moraes, Nicolas Perciani, Pereira, Renan Amarante, da Silva, Thiago Vieira Chicuta, da Silva, Bruno Henrique Baena, de Assis, Gabrielle Policarpo, Campos, Tiago Moreira Bastos, Thim, Gilmar Patrocínio, de Vasconcelos Lanza, Marcos Roberto, de Freitas, Larissa, and Rodrigues, Liana Alvares

Published
2024
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23. Bi2S3 for sunlight-based Cr(VI) photoreduction: investigating the effect of sulfur precursor on its structural and photocatalytic properties.

Author

de Moraes, Nicolas Perciani, Ribeiro, Pedro Malavota, da Silva, Bruno Henrique Baena, Campos, Tiago Moreira Bastos, Thim, Gilmar Patrocínio, de Vasconcelos Lanza, Marcos Roberto, and Rodrigues, Liana Alvares

Abstract

This study investigated the suitability of multiple bismuth sulfide (Bi2S3) samples for the photoreduction of Cr(VI) under simulated sunlight, aiming to elucidate the effect of different sulfide sources (thiourea, thioacetamide, sodium sulfide, potassium sulfide, and ammonium sulfide) on the final structural and photocatalytic properties of this semiconductor. The sulfides were produced through simple precipitation methods, without the necessity of complex methodologies or equipment. Additionally, the effect of thermal treatment on the properties of the Bi2S3 samples was also evaluated. The choice of the sulfide precursor imparted distinct characteristics onto the synthesized Bi2S3, such as distinct morphologies, specific surface areas (SSA), and crystalline structures. Notably, the efficiency of Cr(VI) photoreduction was found to be intricately linked to the adsorption capacity of Bi2S3. In this context, the calcination process emerged as a significant impediment, as it substantially diminished both the SSA and adsorption capacity of the materials. Among the sulfide sources investigated, Bi2S3 synthesized using K2S exhibited superior photoreduction efficiency, attributed primarily to its remarkable adsorption capacity and rod-like morphology. The photoreduction mechanism was determined to be carried out by the direct reaction between Cr(VI) and photogenerated electrons. Regarding operational parameters, initial concentration, pH and temperature had major effects on the photoreduction efficiency; high initial concentrations led to the saturation of the active sites and lower reaction rate constants, whereas lower pHs and higher temperatures favored the photoreduction process. As for the recycle tests of the best photocatalyst, it was discovered a significant efficiency loss between cycles, which was linked to the occlusion of active sites through the formation of chrome-based species on the surface of the photocatalyst. Highlights: Morphology and structure were affected based on the sulfur precursor employed; Photoreduction of the Cr(VI) was strongly linked to the adsorption capacity; The calcination process was unfavorable due to the reduction of surface area. [ABSTRACT FROM AUTHOR]

Published
2024
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37. Synthesis of Nb2O5/C for H2O2 electrogeneration and its application for the degradation of levofloxacin.

Author

Valim, Ricardo Bertholo, Carneiro, Jussara Fernandes, Lourenço, Julio César, Hammer, Peter, dos Santos, Mauro Coelho, Rodrigues, Liana Alvares, Bertazzoli, Rodnei, de Vasconcelos Lanza, Marcos Roberto, and da Silva Rocha, Robson

Subjects
NIOBIUM oxide, CRYSTAL structure, X-ray diffraction, CARBON oxides, HYDROGEN peroxide, INTERSTITIAL hydrogen generation
Abstract

The present work sought to investigate H2O2 generation using a gas diffusion electrode (GDE) composed of carbon with niobium oxide for levofloxacin (LEVO) degradation. Results showed that the oxide formed was Nb2O5 (crystallographic structure was confirmed by XRD; chemical composition detected by XPS), and the increase in the Nb/C ratio led to more crystalline structure and higher crystallite size. The carbon with 5% Nb2O5 presented an average particle size of 5.6 nm, and this material led to the generation of the highest amount of H2O2 (317.6 mg L−1). The C/5% Nb2O5-modified GDE was applied for the degradation of LEVO in an acid medium in the presence and absence of Fe2+ ions. Long-term experiments conducted to analyze the time required for the total removal of LEVO showed that 96% of LEVO and 66% of organic load were removed in 270 min of treatment at the current density of 100 mA cm−2. [ABSTRACT FROM AUTHOR]

Published
2024
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42. Ni3B modified BiVO4 photoanodes for enhanced photoelectrochemical water splitting: The key role of Ni3B on reducing the water oxidation barrier.

Author

Xue, Kehui, Zhu, Haifeng, Zhao, Xingyu, Rodrigues, Liana Alvares, Reddy, D. Amaranatha, Zhang, Yaping, and Yu, Lianqing

Subjects
PHOTOELECTROCHEMISTRY, OXIDATION of water, OXYGEN evolution reactions, OXIDATION kinetics, STANDARD hydrogen electrode, SURFACE charges
Abstract

Bismuth vanadate (BiVO4, BVO) as a promising photoelectrode has been received great attention for photoelectrochemical (PEC) water splitting. However, the slow oxidation kinetics on the surface of BiVO4 limited the PEC water splitting efficiency. Herein, nickel boride (Ni3B, NB) nanoparticles, generally used in electrocatalytic field material, were modified on the surface of BiVO4 photoelectrode as an efficient cocatalyst to accelerate the oxygen evolution reaction. The as-prepared BVO-NB-5P photoelectrode exhibits a remarkable photocurrent density of 1.47 mA·cm−2 at 1.23 V versus the reversible hydrogen electrode (RHE) under air mass (AM) 1.5 G illumination, which is about 2.8 times higher than the bare BiVO4 photoelectrode, and its water splitting rate is 11.3 times higher than bare BiVO4. The PEC studies reveal that the spin coated Ni3B crystal cocatalyst could effectively reduce the water oxidation barrier, and improve the surface charge injection efficiency to 94%, which could boost the photogenerated holes reaction to enhance the PEC performance of BiVO4 photoelectrode. [ABSTRACT FROM AUTHOR]

Published
2023
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43. Solar-based photocatalytic ozonation employing novel S-scheme ZnO/Cu2O/CuO/carbon xerogel photocatalyst: effect of pH, salinity, turbidity, and temperature on salicylic acid degradation.

Author

de Moraes, Nicolas Perciani, dos Santos, Rafaela Dias Moreira, Gouvêa, Maira Elizabeth Vicente, de Siervo, Abner, da Silva Rocha, Robson, Reddy, Devulapalli Amaranatha, Lianqing, Yu, de Vasconcelos Lanza, Marcos Roberto, and Rodrigues, Liana Alvares

Subjects
SALICYLIC acid, OZONIZATION, PH effect, P-N heterojunctions, TURBIDITY
Abstract

This paper proposes the study of a solar-based photocatalytic ozonation process for the degradation of salicylic acid (SA) using a novel S-scheme ZnO/Cu2O/CuO/carbon xerogel photocatalyst. The incorporation of CuO and Cu2O aims to enhance charge mobility through the formation of p-n heterojunctions with ZnO, whereas the carbon xerogel (XC) was selected due to its eco-friendly nature, capacity to stabilize S-scheme heterojunctions as a solid-state electron mediator, and ability to function as a reducing agent under high temperatures. The characterization of the composites demonstrates that the presence of the XC during the calcination step led to the reduction of a fraction of the CuO into Cu2O, forming a ternary semiconductor heterojunction system. In terms of photocatalysis, the XC/ZnO-CuxO 5% composite achieved the best efficiency for salicylic acid degradation, mainly due to the stabilization of the S-scheme charge transfer pathway between the ZnO/CuO/Cu2O semiconductors by the XC. The total organic carbon (TOC) removal during heterogeneous photocatalysis was 80% for the solar-based process and 68% for the visible light process, after 300 min. The solar-based photocatalytic ozonation process was highly successful regarding the degradation of SA, achieving a 75% increase in the apparent reaction rate constant when compared to heterogeneous photocatalysis. Furthermore, a 78% TOC removal was achieved after 150 min, which is half the time required by the heterogeneous photocatalysis to obtain the same result. Temperature, salinity, and turbidity had major effects on the efficiency of the photocatalytic ozonation process; the system's pH did not cause any major performance variation, which holds relevance for industrial applications. [ABSTRACT FROM AUTHOR]

Published
2023
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45. ZnO/CeO2/carbon xerogel composites with direct Z-scheme heterojunctions: Enhancing photocatalytic remediation of 4-chlorophenol under visible light

Author

de Moraes, Nicolas Perciani, primary, Sanmartin, Maitê Birkett de Campos, additional, da Silva Rocha, Robson, additional, de Siervo, Abner, additional, de Vasconcelos Lanza, Marcos Roberto, additional, Reddy, D. Amaranatha, additional, Yu, Lianqing, additional, and Rodrigues, Liana Alvares, additional

Published
2022
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46. Kraft lignin-based carbon xerogel/zinc oxide composite for 4-chlorophenol solar-light photocatalytic degradation: effect of pH, salinity, and simultaneous Cr(VI) reduction

Author

de Moraes, Nicolas Perciani, primary, de Siervo, Abner, additional, Silva, Taynara Oliveira, additional, da Silva Rocha, Robson, additional, Reddy, D. Amaranatha, additional, Lianqing, Yu, additional, de Vasconcelos Lanza, Marcos Roberto, additional, and Rodrigues, Liana Alvares, additional

Published
2022
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