Navegando por Autor "Ardisson, José Domingos"

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An efficient and simple procedure to prepare chemically stable and partially carbon-cleaned magnetite from solid-state synthesis for clinical practices in medical oncology.
(2020) Andrade, Ângela Leão; Almeida, Katia Júlia de; Freitas, Erico Tadeu Fraga; Mesquita, Aline M.; Pereira, Márcio César; Fabris, José Domingos; Fernandez Outon, Luis Eugenio; Ardisson, José Domingos; Domingues, Rosana Zacarias
As far as medical applications for clinical diagnosis and therapy in oncology are concerned, the use of stables magnetic nanoparticles relies on the magnetocaloric response of their ferrofluid suspensions to an applied alternating current magnetic field. To assure their effectiveness as an advanced material for such a medical technology, some critical properties, as any tendency of the nanoparticles to self-agglomerate and of the mag netic core component to somehow change their chemical nature, must be rigorously inhibited. A sample of chemically stable nanoparticles of magnetite ( Fe3+ 2 Fe2+O2− 4 ) was synthesized through the method consisting of burning a synthetic commercial maghemite (γFe3+ 2 O2− 3 ) with admixed sucrose, to partially reduce Fe3+ → Fe2+. The residual carbon, formed on burning the sucrose, tends to coat the nanoparticles and acts as a protective layer hindering the freshly synthesized hot magnetite from being promptly re-oxidized, on cooling the sample in the open-air atmosphere. As a drawback, this carbon layer tends to be a thermal insulator and must be removed, in order to make the magnetite nanoparticles able to be used as a magnetocaloric material and dissipate heat. A chemically gentle removal of the residual carbon was assayed by treating the sample with H2O2 under stirring or sonication either for 30 min or 60 min. The intrinsic atomic and crystalline structures and other essential properties of this core-shell system were assessed by gas adsorption analysis (BET), powder X-ray diffraction, Fourier-transform infrared spectrometry, Mossbauer ¨ spectroscopy and transmission electron microscopy. Theo retical analyses based on the density functional theory (DFT) were used to interpret the harmonic infrared spectra for the produced magnetite. The efficiency in removing the residual carbon layer formed on the magnetite grain surface was checked by saturation magnetization measurements and CHN elemental analysis. The heat releasing ability of the prepared magnetic sample was evaluated under an AC-induced magnetic field. These results evidenced that the treatment with H2O2 was efficient enough to remove, even though not completely, most of the residual carbon layer, which made the saturation magnetization and the heat released by the treated samples significantly greater than that of the untreated carbon-coated grains. The resulting nano magnetite was found to be a sufficiently clean material for being used for hyperthermia-based procedures, particularly for medical diagnosis and therapy, in oncology.
Catalytic carbon deposition-oxidation over Ni, Fe and Co catalysts : a new indirect route to store and transport gas hydrocarbon fuels.
(2013) Oliveira, Patrícia E. F.; Ribeiro, Leandro Passos; Rosmaninho, Marcelo Gonçalves; Ardisson, José Domingos; Dias, Anderson; Oliveira, Luiz Carlos Alves de; Lago, Rochel Montero
In this work, a new two-step route to store and transport associated natural gas, promoted by Ni, Fe and Co supported catalyst was presented. Initially, CH4 is converted into carbon deposits (M/C composite), being Fe catalyst the most active catalyst. In Step 2, M/C composite reacts with H2O producing H2, CO and CH4. TPO experiments showed that efficiency and selectivity of oxidation depends on the metal. Ni catalyst produced mainly H2 and CO, while Fe system was more selective to convert carbon into CH4. The formation of C2 and C3 compounds suggests the presence of a Fischer Tropsch like process.
d-FeOOH : a superparamagnetic material for controlled heat release under AC magnetic field.
(2013) Chagas, Poliane; Silva, Adilson Cândido da; Passamani, Edson Caetano; Ardisson, José Domingos; Oliveira, Luiz Carlos Alves de; Fabris, José Domingos; Paniago, Roberto Magalhães; Monteiro, Douglas Santos; Pereira, Márcio César
Experimental evidences on its in vitro use reveal that d-FeOOH is a material that release-controlled amount of heat if placed under an AC magnetic field. d-FeOOH nanoparticles were prepared by precipitating Fe(OH)2 in alkaline solution followed by fast oxidation with H2O2. XRD and 57Fe Mo¨ssbauer spectroscopy data confirmed that d-FeOOH is indeed the only iron-bearing compound in the produced sample. TEM images evidence that the averaged particle sizes for this d-FeOOH sample is 23 nm.Magnetization measurements indicate that these d-FeOOH particles behave superparamagnetically at 300 K; its saturationmagnetization was found to be 13.2 emu g-1; the coercivity and the remnant magnetization were zero at 300 K. The specific absorption rate values at 225 kHz were 2.1, 6.2, and 34.2 W g-1, under 38, 64, and 112 mT, respectively. The release rate of heat can be directly controlled by changing the mass of d-FeOOHnanoparticles. In view of these findings, the so-preparedd-FeOOHis a real alternative tobe further tested as amaterial formedicalpractices in therapies involving magnetic hyperthermia as in clinical oncology.
Effect of Sn on methane decomposition over Fe supported catalysts to produce carbon.
(2011) Freitas, Patrícia Elizabeth de; Ribeiro, Leandro Passos; Rosmaninho, Marcelo Gonçalves; Ardisson, José Domingos; Dias, Anderson; Lago, Rochel Montero
In this work, alumina-supported Sn containing Fe catalysts were investigated in CVD reactions (Chemical Vapor Deposition) using methane for carbon production. The catalysts were prepared with 10 wt.% of Fe (as Fe2O3) and 3, 6 and 12 wt.% of Sn (as SnO2) supported on Al2O3 named hereon Fe10Sn3A, Fe5Sn6A and Fe10Sn12A, respectively. These catalysts were characterized by SEM, TPCVD, TPR, TG, Raman,XRDand 57Fe and 119Sn Mössbauer spectroscopy.Methane reacts with Fe10A catalyst (without Sn) in the temperature range 680–900◦C to produce mainly Fe0, Fe3 C and 20 wt.% of carbon deposition. TPR and TPCVD clearly showed that Sn strongly hinders the CH4 reaction over Fe catalyst. 57Fe Mössbauer suggested that in the presence of Sn the reduction of Fe+3 by methane becomes very difficult. 119Sn Mössbauer showed Sn+4 species strongly interact with metallic iron after CVD, producing iron-tin phases such as Fe3SnC and FeSn2. This interaction Sn–Fe increases the CVD temperatures and decreases the carbon yield leading to the production of more organized forms of carbon such as carbon nanotubes, nanofibers and graphite.
Effect of tetramethylammonium hydroxide on nucleation, surfacemodification and growth ofmagnetic nanoparticles.
(2012) Andrade, Ângela Leão; Fabris, José Domingos; Ardisson, José Domingos; Valente, Manuel Almeida; Ferreira, José Maria da Fonte
Nanoparticles of magnetite (Fe3O4) were obtained by reacting ferric chloride with sodium sulphite, through the reductionprecipitation method. The effects of adding tetramethylammonium hydroxide (TMAOH) during or after the precipitation of the iron oxide were studied in an attempt to obtain well-dispersed magnetite nanoparticles. Accordingly, the following experimental conditions were tested: (i) precipitation in absence of TMAOH (sample Mt), (ii) the same as (i) after peptizing with TMAOH (Mt1), (iii) TMAOH added to the reaction mixture during the precipitation of magnetite (Mt2). Analyses with transmission electron microscopy (TEM), X-ray diffraction, M¨ossbauer spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), zeta potential, and magnetization measurements up to 2.5 T revealed that magnetite was normally formed also in the medium containing TMAOH. The degree of particles agglomeration was monitored with laser diffraction and technique and inspection of TEM images. The relative contributions of N´eel and Brownian relaxations on the magnetic heat dissipation were studied by investigating the ability of suspensions of these magnetite nanoparticles to release heat in aqueous and in hydrogel media. Based on ATR-FTIR and zeta potential data, it is suggested that the surfaces of the synthesized magnetite particles treated with TMAOH become coated with (CH3)4N+ cations.
Enhanced photocatalytic activity of TiO2/γ-Fe2O3 by using H2O2 as an electron acceptor under visible light radiation.
(2020) Oliveira, Victor L.; Lima, André Luiz Dias; Gabriel Filho, José Balena; Pereira, Márcio César; Souza, Thainá Stefanie Ferreira; Ardisson, José Domingos; Machado, Alan Rodrigues Teixeira; Silva, Adilson Cândido da
TiO2 is a photocatalyst widely used for the degradation of organic compounds in aqueous media; however, it presents some difficulties for application on larger scales. The biggest limitations are its bandgap value of 3.2 eV which corresponds to the UV range of the spectrum and its difficult removal from the reaction medium after the reaction. An alternative to enhance the photocatalytic activity of TiO2 consists in design heterojunctions with semiconductors that are active under visible light irradiation. Some reports have described the magnetic property and synthesis procedures based on inexpensive and abundant raw material. In this work, we synthesized photocatalysts based on γ−Fe2O3impregnated with different levels of TiO2. This may contribute to improving the wide application of TiO2 in water, since γ-Fe2O3 has magnetic features that facilitate the removal of the catalyst after the reaction run. The materials were characterized by X-ray diffraction, analysis of adsorption/desorption of N2, reflectance diffuse, and 57Fe Mössbauer spectroscopy. The photocatalytic activity of the materials was tested for removing rhodamine under visible or visible light in the presence of H2O2. From the X-ray diffraction and 57Fe Mössbauer spectroscopy data, it was observed the formation of γ-Fe2O3 phase with small particle. Without visible light, only 45% of RhB was adsorbed, and with the light on, there is no increase in removal after 60 min. However, after adding H2O2, the photocatalytic activity of material was significantly improved, reaching 80% of dye removal. Tests using scavengers of reactive species revealed that − O2 and OH are the main species in this system. Moreover, the H2O2 retards the electron−hole recombination, thus increasing its photocatalytic activity. The ESI-MS analysis revealed that in 15 min of reaction, deethylation (m/z = 415, 388), deamination (m/z = 301 and 279), and rhodamine B severe oxidation products (m/z < 250) were present in solution, and TOC analysis confirms the mineralization of the rhodamine.
Facile preparation of carbon coated magnetic Fe3O4 particles by a combined reduction/CVD process.
(2011) Tristão, Juliana Cristina; Oliveira, Aline A. S.; Ardisson, José Domingos; Dias, Anderson; Lago, Rochel Montero
In this work, we report a simple method for the preparation of magnetic carbon coated Fe3O4 particles by a single step combined reduction of Fe2O3 together with a Chemical Vapor Deposition process using methane. The temperature programmed reactionmonitored by Mo¨ ssbauer, X-ray Diffraction and Raman analyses showed that Fe2O3 is directly reduced by methane at temperatures between 600 and 900 8C to produce mainly Fe3O4 particles coated with up to 4 wt% of amorphous carbon. Thesemagneticmaterials can be separated into two fractions by simple dispersion in water, i.e., a settled material composed of large magnetic particles and a suspended material composed of nanoparticles with an average size of 100–200 nm as revealed by Scanning Electron Microscopy and High-resolution Transmission Electron Microscopy. Different uses for these materials, e.g., adsorbents, catalyst supports, rapid coagulation systems, are proposed.
High water oxidation performance of W-Doped BiVO4 photoanodes coupled to V2O5 rods as a photoabsorber and hole carrier.
(2018) Oliveira, Andreia Teixeira de; Rodriguez, Mariandry del Valle Rodriguez; Andrade, Tatiana Santos; Souza, Helen E. A. de; Ardisson, José Domingos; Oliveira, Henrique dos Santos; Oliveira, Luiz Carlos Alves de; Lorençon, Eudes; Silva, Adilson Cândido da; Nascimento, Lucas Leão; Patrocinio, Antonio Otavio de Toledo; Pereira, Márcio César
Monoclinic BiVO4 is recognized as a promising photoanode for water oxidation, but its relatively wide bandgap energy (Eg ≈2.5 eV) and poor charge transport limit the light absorption (ηabs) and charge separation (ηsep) efficiencies, thus resulting in low photocurrents. To solve these drawbacks, here the ηabs × ηsep product has been decoupled by combining W‐doped BiVO4 and V2O5 rods (Eg ≈2.1 eV) for simultaneously increasing the light harvesting and the charge separation in photoanodes under back‐side illumination. In this strategy, V2O5 rods maximize the light absorption and hole transport throughout the W‐BiVO4 film, making more holes to achieve the V2O5/W‐BiVO4/H2O interface to trigger the water oxidation reaction with photocurrents as high as 6.6 mA cm−2 at 1.23 VRHE after 2 h reaction. Notably, under back‐side illumination, the W‐BiVO4/V2O5 photoanode exhibited ηabs × ηsep of 74.5 and 93.0% at 0.5 and 1.23 VRHE, respectively, the highest values reported up to date for BiVO4‐based photoelectrodes. This simple strategy brings us closer to develop efficient photoanodes for photoelectrochemical water splitting devices.
Magnetically induced heating by iron oxide nanoparticles dispersed in liquids of different viscosities.
(2020) Andrade, Ângela Leão; Cavalcante, Luis Carlos Duarte; Fabris, José Domingos; Pereira, Márcio César; Fernandez Outon, Luis Eugenio; Pedersoli, Davyston Carvalho; Ardisson, José Domingos; Domingues, Rosana Zacarias; Ferreira, José Maria da Fonte
The AC magnetically induced heating characteristics of uncoated and silica-coated magnetic iron oxide nano particles dispersed in liquids of different viscosities were investigated. The aim was to synthesize and prepare uncoated and silica-coated nanoparticles of maghemite, and evaluate their ability to hyperthermically dissipate heat under an applied AC magnetic field when they are dispersed in liquids of different viscosities. A conceptual approach on the relative contributions of the Néel and the Brownian relaxation mechanisms to the hyperthermic heating of these suspensions is proposed. The microstructure, the physical and chemical properties of the un coated and silica-coated nanoparticles were assessed by transmission electron microscopy; powder X-ray dif fraction; 57Fe Mössbauer spectroscopy; Fourier transform infrared spectroscopy; zeta potential measurements; and conventional chemical analysis. Results of the Rietveld refinement of the XRD patterns and analysis of the collected Mössbauer data are well consistent with maghemite as being the only iron oxide phase. The mean diameters of the uncoated nanoparticles increased from ~6 to 7 nm, to 35 and 78 nm, for added silica coating amounts varying from 1 to 6-fold, respectively. Zeta potential measurements confirmed the efficiency of the nanoparticles sol-gel coating method. When dispersed in low viscosity media (water, triethanolamine, ethylene glycol), uncoated nanoparticles efficiently release heat via both Néel and Brown relaxation mechanisms under an applied oscillating magnetic field, achieving a temperature raise of approximately 21 °C. The silica layers tend to inhibit the Brownian motion of coated particles, making heat dissipation to be preferentially governed by the Néel relaxation of the magnetization vector. This leads to modest rises in temperature of 9 °C when they are dispersed in water or in the PVC (polyvinyl chloride). SAR tests indicate that the maghemite-silica core-shell systems might be useful for advanced technologies in medical practices based on local hyperthermia, particularly in oncology.
Preparation and characterization of Fe3O4-Pt nanoparticles.
(2017) Andrade, Ângela Leão; Cavalcante, Luis Carlos Duarte; Fabris, José Domingos; Pereira, Márcio César; Ardisson, José Domingos; Domingues, Rosana Zacarias
Pt and Pt-based nanomaterials are active anticancer drugs for their ability to inhibit the division of living cells. Nanoparticles of magnetite containing variable proportions of platinum were prepared in the laboratory. The magnetite nanoparticles with platinum (Pt-Fe3O4) were obtained by reducing the Fe3+ of the maghemite (γ Fe2O3) mixed with platinum (II) acetylacetonate and sucrose in two inversely coupled ceramic crucibles and heated in a furnace at 400 ◦C for 20 min. The formed carbon during this preparation acts to chemically reduce the ferric iron in maghemite. Moreover, its residual layer on the particle surface prevents the forming magnetite from oxidizing in air and helps retain the platinum in the solid mixture. The produced Pt-magnetite samples were characterized by 57Fe-M¨ossbauer spectroscopy, powder X-ray diffraction, scanning electron microscopy, and magnetization measurements.Measurements of AC magnetic-field-induced heating properties of the obtained nanocomposites, in aqueous solution, showed that they are suitable as a hyperthermia agent for biological applications.
Preparation of composite with silica-coated nanoparticles of iron oxide spinels for applications based on magnetically induced hyperthermia.
(2013) Andrade, Ângela Leão; Fabris, José Domingos; Pereira, Márcio César; Domingues, Rosana Zacarias; Ardisson, José Domingos
It is reported a novel method to prepare magnetic core (iron oxide spinels)–shell (silica) composites containing well-dispersed magnetic nanoparticles in aqueous solution. The synthetic process consists of two steps. In a first step, iron oxide nanoparticles obtained through co-precipitation are dispersed in an aqueous solution containing tetramethylammonium hydroxide; in a second step, particles of this sample are coated with silica, through hydrolyzation of tetraethyl orthosilicate. The intrinsic atomic structure and essential properties of the core–shell system were assessed with powder X-ray diffraction, Fourier transform infrared spectrometry, Mössbauer spectroscopy and transmission electron microscopy. The heat released by this ferrofluid under an AC-generated magnetic field was evaluated by following the temperature evolution under increasingmagnetic field strengths.Results strongly indicate that this ferrofluid based on silica-coated iron oxide spinels is technologically a very promising material to be used in medical practices, in oncology.
Production of nanostructured magnetic composites based on Fe0 nuclei coated with carbon nanofibers and nanotubes from red mud waste and ethanol.
(2011) Oliveira, Aline A. S.; Tristão, Juliana Cristina; Ardisson, José Domingos; Dias, Anderson; Lago, Rochel Montero
In this work, a catalytic CVD process using ethanol as carbon source was used to convert an iron rich waste, i.e. red mud (RM), in a magnetic composite. TPCVD (temperature programmed CVD), XRD, Mössbauer, EDS, magnetic measurements, TG/DTA, CHN, BET, Raman, SEM and TEM showed that ethanol gradually reduces the iron phases in the RM to Fe3O4 at 500 ◦C and to Fe1−xO at 600 ◦C. At higher temperatures Fe0 and Fe carbide are the main phases produced with the formation of large amounts of carbon (30–50 wt%) especially as nanotubes and nanofibers. These magnetic materials can be separated into two fractions by simple dispersion in water, i.e. a settled material composed of large magnetic particles and the suspended material composed of nanoparticles with average size of 10–100 nm. The carbon in the composites can be activated with CO2 increasing the surface area from 79 to 185m2 g−1. The magnetic composites were used as adsorbent of model dyes methylene blue and indigo carmine showing excellent results. The composites were also used as support to produce a recyclable Pd catalyst. Tests for the 1,5-cyclooctadiene hydrogenation showed that the catalyst can be easily magnetically separated from the reaction medium and reused for five consecutive times with no deactivation or change in selectivity.
Spectroscopic investigation of organotin (IV) derivatives of 7-epiclusianone : a preliminary in vitro antitumor evaluation of HN-5 human carcinoma cell.
(2009) Vieira, Flaviana Tavares; Maia, José Roberto da Silveira; Vilela, Marcelo José; Ardisson, José Domingos; Santos, Marcelo Henrique dos; Oliveira, Tânia Toledo de; Nagem, Tanus Jorge
A series of organotin(IV) compounds have been prepared by reaction with 7-epiclusianone (Epi), a natural product extracted from fruits of Rheedia gardneriana. This compound has an interesting motif with several coordinating sites for metal-ligand bond formation, and in solution, it shows a keto-enol tautomerism. The NMR of the organotin(IV) derivatives has revealed intramolecular hydrogen bonding, indicating that the keto-enol tautomerism of 7-epiclusianone is not involved upon coordination of those, but the absence of this bonding type in the case of the SnCl4 derivative suggests a strong interaction. The Mössbauer spectroscopy has revealed five- and six-fold coordination for the organotin(IV) and SnCL» derivatives in the solid state. However, in solution all tin complexes have six-fold coordination, as shown by "9Sn NMR. The overall data point out that the organotin(IV) precursors SnClxPri4_x (x = 1, 2) are weakly bonded to the 7- epiclusianone, except the SnC^. Bioassay in vitro of the substance test [SnClPh3(£/7/)] (1) has been investigated using two epithelial cells: normal MDCK from canine kidney, and IIN-5 from a human carcinoma of the tongue. The results clearly demonstrate that the time for cellular reproduction has been reduced in the presence of the substance test.
Structural characteristics of chalcopyrite from a Cu(Au) ore deposit in the Carajás Mineral Province, Brazil.
(2011) Ribeiro, Andreza Aparecida; Lima, Diana Quintão; Duarte, Hélio Anderson; Murad, Enver; Pereira, Márcio César; Suita, Marcos Tadeu de Freitas; Ardisson, José Domingos; Fabris, José Domingos
t Mössbauer spectra and X-ray diffraction data show a chalcopyrite from the Cristalino Cu(Au) deposit in the Carajás Mineral Province in northern Brazil to consist of a single, tetragonal phase. This is in stark contrast to a previously described chalcopyrite from the Camaquã copper mine in southern Brazil, obviously reflecting differences in mineral (and thus ore deposit) genesis.
Thermal cracking of oleic acid promoted by iron species from iron ore tailings for the production of ketones and fuels.
(2022) Luciano, Vivian Andrade; Paula, Fabiano Gomes Ferreira de; Pinto, Paula Sevenini; Prates, Caroline Duarte; Pereira, Rafael César Gonçalves; Ardisson, José Domingos; Rosmaninho, Marcelo Gonçalves; Teixeira, Ana Paula de Carvalho
Iron ore tailings (IOT) are rich in iron oxides and silica and can be used for different applications such as allow the thermal cracking of fatty acids for the production of fuels and products with high added value. Thus, this work aimed to use of IOT as an iron source for the production of high-value products using oleic acid (OA) as carbon sources. These compounds were produced from a thermal decomposition reaction, from the mixture of OA and IOT, in a high pressure reactor (12.5 bar), using the ratio of 1:1 wt (acid:IOT), in temperatures between 250 and 450 ◦C (3 and 12 h). The results showed that for all reactions, the solid products obtained showed a percentage of less than 6 % of carbon material and different iron phases (Fe2O3, Fe3O4 and FeOOH). For the reactions carried out at 250 and 350 ◦C/3h the main fraction obtained was the liquid, however the compostion was mainly the starting compound and iron oleate. For the reactions carried out at 400 and 450 ◦C/3h, the main fraction was gas, mainly hydrogen. For the reaction carried out at 350 ◦C for 12 h the mass balance showed the formation of similar amounts of liquid and gaseous products. Liquid products formed ketones as the main product, while gaseous products were identified and presented greater selectivity for C3 hydrocarbons.
Tin(IV) compounds derivatives of reaction between Organotin(IV), SNCL4 and rutin trihydrate : characterization and hypolipidemic effects.
(2004) Mello, Vanessa Joia de; Maia, José Roberto da Silveira; Oliveira, Tânia Toledo de; Ardisson, José Domingos; Nagem, Tanus Jorge; Ardisson, José Domingos; Patricio, Patrícia Santiago de Oliveira; Lima, Geraldo Magela de
Equimolar reactions involving SnClPh3, SnCl2Ph2, SnCl3Ph and SnCl4 and rutin trihydrate (Quercetin-3- rutinoside) produced organotin(IV) polymers, which have been characterized by infrared spectroscopy, 'H, n C and "9Sn NMR, Mössbauer spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and microanalysis. The NMR ('Η, 13C) and "9Sn Mössbauer spectroscopy have revealed dephenylation of the starting organotin(IV) materials. The overall data have revealed a six-coordination for the Sn(IV) centre in solution as well as in solid state. DSC and GPC techniques have confirmed the formation of macromolecules for those adducts with an average molar mass higher than 7.0x10' g/mol. The hypolipidemic effect of total cholesterol reduction in male New Zealand rabbits was comparable to calcic atorvastatin, a commercial drug for treatment of hyperlipidemic patients.
Use of iron and bio-oil wastes to produce highly dispersed Fe/C composites for the photo-Fenton reaction.
(2017) Mendonça, Fernanda Gomes de; Rosmaninho, Marcelo Gonçalves; Fonseca, Philipe Xavier da; Soares, Ricardo Reis; Ardisson, José Domingos; Tristão, Juliana Cristina; Lago, Rochel Montero
This work describes the synthesis, characterization, and application of an active heterogeneous photo-Fenton system obtained from two different wastes, i.e., laterite (an iron mining waste) and the acid aqueous fraction (AAF) from biooil production. AAF with high acidity (ca. 3 molH+L−1) and organic concentration (25 wt.%) obtained from biomass flash pyrolysis was used for the efficient extraction of Fe3+ from laterite waste. After extraction, the mixture Fe3+/AAF was dried and treated at different temperatures, i.e., 500, 650, and 800 °C, to obtain Fe/C reactive composites. Mössbauer, XRD, TG, elemental analyses, and SEM/EDS showed the presence of highly disperse Fe oxide nanoparticles at 500 and 650 °C and Fe0 particles in the material obtained at 800 °C with carbon contents varying from 74 to 80 %. The three composites were tested as heterogeneous catalysts in the photo-Fenton reaction for the oxidation of the model dye contaminant methylene blue, showing high activities at neutral pH.