Sergio Morales-Torres

University of Granada | UGR · Department of Inorganic Chemistry

Novel carbon xerogels doped with heteroatoms (O, N, S) were prepared by sol–gel polymerization of resorcinol with heterocyclic aldehydes containing them. All doped materials presented higher O-contents than the reference material prepared with formaldehyde, and significant S- or N-loadings in the corresponding samples. Carbon xerogels were micro-me...

The performance of carbon xerogel/TiO2 composites in ethylene photo-oxidation was analyzed under dynamic conditions considering various parameters, namely sulfur doping, dry vs. humid conditions and type of radiation (ultraviolet, UV, vs. visible light, Vis). The catalysts were synthesized using an acid-catalyzed sol-gel process and characterized w...

Two series of TiO2-based zeolite composites (BEA structures) were prepared by employing a sol–gel method using two different synthesis approaches, i.e., acidic and basic media. Different photocatalytic composites obtained with increasing amounts of TiO2 (10–50 wt%) were thoroughly characterized and subsequently tested in the photooxidation of ethyl...

A series of adsorbents (activated carbons, ACs) were synthesized by physical and chemical activation of olive stones (OS) and their textural and chemical characteristics determined by complementary techniques such as N2 and CO2 physisorption, pH of the point zero of charge (pHPZC), HRSEM or XPS. Samples with a wide range of physicochemical properti...

A family of sustainable carbon catalysts with different chemical surface, active and selective for the synthesis of benzodiazepine 1 (BDZ), from o-phenylendiamine (OPD) 2 and acetone 3, under mild conditions, is reported. Catalysts were prepared by acids treatments with H2SO4 or H3PO4 of an activated carbon doped with ZnO at 3% wt (N3Zn) and, subse...

In this study, co-precipitation and hydrothermal synthesis methods were employed to prepare two types of magnetite nanoparticles (MNPs). An activated carbon derived from olive stones (OSAC) was used as MNPs-support. The physicochemical properties of the resulting OSAC-MNPs catalysts were determined using various characterization techniques. A more...

The growing demand for food has led to an increase in the use of herbicides and pesticides over the years. One of the most widely used herbicides is glyphosate (GLY). It has been used extensively since 1974 for weed control and is currently classified by the World Health Organization (WHO) as a Group 2A substance, probably carcinogenic to humans. T...

From the most classic carbon materials (CMs) to the advanced ones, all of them integrate a promising catalyst set in terms of sustainability and energy efficiency for a greener future. Different synthetic strategies concerning to the catalytic synthesis of relevant N‐containing heterocycles are herein described to address the great potential of the...

Bimetallic (Fe-Cu) and reduced graphene oxide (rGO)/FeCu catalysts at 0.2% wt. were developed by a co-precipitation method, modifying the Fe-Cu molar proportions (i.e., Fe40Cu60, Fe20Cu80 and Fe10Cu90) and tested for the degradation of the cytostatic drug, cyclophosphamide (CP) in aqueous solution using the photo-Fenton process (UV-Vis). Physicoche...

Transition metal (TM)-carbon aerogels, where TM = Mo, Fe, Co or Cu, were found to be active and selective catalysts for the synthesis of quinoxalines 1, from o-phenylenediamine 2 and α-hydroxy ketones 3, becoming an efficient and sustainable alternative to other carbon-based catalysts or even MOF. Doping metal phase consisting of the corresponding...

Sol-gel method was used to prepare palladium-modified TiO2 powder photocatalysts (Pd atomic percentage range of 0–1.00). The materials were characterized by X-ray diffraction, N2 physisorption, UV–Vis diffuse reflectance spectroscopy and transmission electron microscopy. Photocatalytic activity was tested for phenol degradation, with UV and visible...

Graphitic carbon nitride (g-C3N4) was synthetized by a one-step thermal method from different N-rich precursors, namely melamine, dicyandiamide, urea, thiourea and cyanamide. The structure, optical and physicochemical properties of g-C3N4 materials were studied by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Ra...

A series of adsorbents and photocatalysts were developed using agricultural residues (olive stones) as raw materials. Activated carbons (ACs) were synthesized by physical activation and posteriorly, impregnated with TiO2 by a hydrothermal method. Both adsorbents (ACs) and composites (carbon-TiO2) were texturally, morphologically and chemically char...

Heterogeneous catalysts based on magnetite nanoparticles, Fe3O4, were prepared by the chemical coprecipitation method using iron (III) chloride as a salt precursor. The physicochemical properties of the nanoparticles were determined by different techniques and the efficiency was evaluated for the degradation of the cytostatic drug, 5-fluorouracil (...

The degradation of organic matter present in olive mill wastewater (OMW) and the recovery of water were studied by the integration of catalytic wet peroxidation (CWPO) and direct contact membrane distillation (DCMD) for the first time. The oxidation step was performed in a fixed–bed reactor (FBR) working in continuous mode (pH0 = 4.0 ± 0.2, 60 °C,...

One of the major keys in the design of new high-performance catalysts is the optimization of the synthesis procedure to tailor the physicochemical properties. In this context, the preparation of catalysts based on porous carbon gels is summarized. The influence of the different synthesis parameters along the preparation of supported or metal-doped...

Iron oxide catalysts supported on activated carbon prepared from olive stones (OSAC–Fe) were used for the catalytic wet peroxide oxidation of refractory polyphenolic solutions and real olive mill wastewater (OMW) in a fixed-bed reactor (FBR). Catalysts were prepared with different precursors and Fe-loadings. The resulting catalysts were essentially...

A resistive sensor based on films of carbon gel-TiO2 nanocomposites prepared with different percentages of TiO2 by a sol-gel process, was developed to determine ammonia gas. A thin film of carbon gel-TiO2 nanocomposites dispersed in poly(vinylidenfluoride) and deposited on glass slides containing silver electrodes are used as NH3 sensor. The resist...

A series of adsorbents was developed by physical (CO 2) and chemical (KOH) activation of two bio-residues: olive stones (OS) and wood from olive tree pruning (OTP). The physicochemical properties of such materials were determined and correlated with their adsorptive performance in the removal of phenolic compounds of olive mill wastewater (OMW). Ad...

Ennoblement of carbon dioxide, particularly the one produced by anaerobic digestion or by biomass combustion, is a motivation to develop novel or improving already existing processes. In this context, an interesting idea is to use carbon dioxide combined together with methane and water. Therefore, bi-reforming of methane (BRM) for syngas production...

A highly efficient methodology for the selective synthesis of nitrogen heterocycles via Friedländer reaction using carbon materials supported ZnO catalysts under the green chemistry domain is presented. The influence of the physicochemical properties of different carbon supports, in particular an activated carbon (AC), multi-walled carbon nanotubes...

Graphitic carbon nitride (g-C3N4) was used to enhance the photocatalytic activity of ZnO nanoparticles for the degradation of 5-fluorouracil (5-FU) cytostatic drug under UV-LED irradiation. CN/ZnO composites were synthetized by an easy one-pot thermal method, varying the g-C3N4 loading, i.e., from 10 to 67 wt% and a post-thermal exfoliation in air....

TiO2 in situ growth on three commercial membranes (polysulfone, polyvinylidene fluoride –PVDF and polytetrafluoroethylene –PTFE) and its hydrothermal post-crystallization to transform TiO2 into a photocatalytically-active phase, were investigated under mild synthesis conditions to preserve the textural properties of the supports. The membranes were...

Photocatalysts are often employed as suspended particles (slurries) in batch reactors, and thus a second step is required for catalyst separation from the treated water, limiting its recovery and reuse. Photocatalytic membranes (PMs), in which photocatalyst nanoparticles are deposited or immobilized to enhance their performance, can provide a compl...

Graphene oxide (GO) is used to enhance the photocatalytic activity of ZnO nanoparticles for the degradation of vanillic acid (VA) under simulated solar light and visible-LED (λ > 430 nm). ZnO-GO composites are prepared by a mixing and sonication process with different GO loadings (i.e., from 1.8 to 6.5 wt.%). The materials are extensively character...

This Special Issue was designed based on two complementary principles, both aimed at developing environmentally friendly production processes, in which catalysis plays a leading role [...]

Escherichia coli colonies were grown on different supports for the removal of nitrates from water. A carbon material and different commercial metal oxides, such as SiO2, TiO2 and Al2O3, and their corresponding carbon–metal oxide composites were studied. The physicochemical properties were analyzed by different techniques and the results were correl...

This manuscript is focused on the relationship between sol-gel synthesis processes and the development of new active phases with fitted morphology, porosity and surface chemistry. The influence of the above parameters on the catalytic performance of the prepared materials for the aromatization of n-hexane to benzene is also evaluated. Different ser...

Carbon nanomaterials have demonstrated their potential as adsorbents, self-catalysts, and catalyst supports, to effectively remove pollutants from air and water. These materials possess unique properties, such as inertness, stability in acidic and basic media, and mainly the ability to tune their porosity and surface chemistry. Thus, the hydrophobi...

A by-product of olive mill’s operation (olive stone, OS) was transformed into activated carbon (AC) and used as support to prepare Fe-based catalysts, which were employed on the catalytic wet peroxide oxidation (CWPO) of olive mill wastewater (OMW). Three Fe-impregnation routes were tested: incipient wetness impregnation (IWI), adsorption (Ads), an...

Glucose–carbon hybrids were synthetized with different carbon materials, namely carbon nanotubes, reduced graphene oxide, carbon black and activated carbon by a hydrothermal treatment. These carbon hybrids were used as Pt-supports (1 wt.%) for the furfural (FUR) hydroconversion in the gas phase at mild operating conditions (i.e., P = 1 atm and T =...

Three magnetic carbon nanotube (CNT) samples, named A30 (N-doped), E30 (undoped) and E10A20 (selectively N-doped), synthesized by catalytic chemical vapor deposition, were modified by introducing oxygenated surface groups (oxidation with HNO 3 , samples CNT-N), and by heat treatment at 800 °C for the removal of surface functionalities (samples CNT-...

P, B and N-doped carbon blacks prepared with H3PO4, urea and H3BO3 were tested as catalysts in the wet peroxide oxidation of a concentrated 4-nitrophenol (4-NP) model solution (C4-NP = 5 g·L⁻¹). The highest catalytic activity was found for P-doped carbon black (complete removal of 4-NP after 4 h at 80 °C, Ccat = 2.5 g·L⁻¹, CH2O2=17.8g·L−1 and initi...

Different series of hybrid carbon/TiO2 composites were prepared and used as photocatalysts. To improve the dispersion of the Ti-precursors during the impregnation process, the microcrystalline cellulose (MCC), as a source of carbon, was dissolved in water by treatment with inorganic acids (HNO3 or H3PO4 or mixture) or bases (NaOH/urea). This treatm...

In this work, the combination of advanced oxidation technologies (AOTs) and direct contact membrane distillation (DCMD) was investigated for the treatment of municipal wastewater collected from a secondary clarifier of a conventional municipal wastewater treatment plant (MWWTP). Average efficiencies higher than 95 % were obtained with ozonation (O3...

Correction for ‘Syngas production by bi-reforming methane on an Ni–K-promoted catalyst using hydrotalcites and filamentous carbon as a support material’ by Adelino F. Cunha et al. , RSC Adv. , 2020, 10 , 21158–21173, DOI: 10.1039/D0RA03264F.

The resorcinol (R)-formaldehyde (F) polymerization was carried out in different experimental conditions to obtain RF/Mo doped carbon xerogels with different morphology, porosity and nature and dispersion of metal. Attractive or repulsive electrostatic interactions were forced in the starting aqueous solution of RF-monomers using different synthesis...

Steam reforming of methane (SRM) and dry reforming of methane (DRM) are frequently used in the production of syngas; however, the bi-reforming of methane (BRM) is an interesting and alternative process. In this study, BRM was studied over MgO, a layered double hydroxide (LDH) phase that was destroyed between 600 °C and 900 °C during the reaction. I...

Functionalized graphene derivatives including graphene oxide (GO), reduced graphene oxide (rGO), and heteroatom (nitrogen/sulphur (N/S) or boron (B))-doped graphene were used to synthesize composites with TiO2 (T). The photocatalytic performance of composites was assessed for the degradation of Orange G dye (OG) under simulated solar light. All the...

A series of biochars and activated carbons (ACs) was prepared combining carbonization and physical or chemical activation of cheap and abundant residues of the olive oil industry. These materials were used as Fe-support to develop low-cost catalysts for the heterogeneous Fenton-like oxidation of simulated olive mill wastewater (OMW), the highly pol...

In this work, a series of carbon xerogel/graphene hybrids were synthesized from resorcinol and formaldehyde by adding increasing loadings of graphene oxide (GO) solution. Resulting samples were functionalized with urea and characterized by SEM, adsorption-desorption isotherms of N2 at 77 K, X-ray photoelectron spectroscopy (XPS), and Raman spectros...

Carbon–Ti nanocomposites were prepared by a controlled two-step method using microcrystalline cellulose as a raw material. The synthesis procedure involves the solubilization of cellulose by an acid treatment (H3PO4 or HNO3) and the impregnation with the Ti precursor followed of a carbonization step at 500 or 800 °C. The type of acid treatment lead...

This chapter provides an overview on the application of cellulose/titania composites for the removal of organic pollutants by heterogeneous photocatalysis. Cellulose is presented to overcome the drawbacks of titania as semiconductor, in particular, a low activity under visible irradiation and a poor quantum efficiency. The coupling of cellulose and...

Carbon materials are one of the most fascinating materials because of their unique properties and potential use in several applications. They can be obtained from residues or by using advanced synthesis technologies like chemical vapour deposition. The carbon family is very wide, it includes from classical activated carbons to more advance others,...

Carbon materials are one of the most fascinating materials because of their unique properties and potential use in several applications. They can be obtained from agricultural waste, organic polymers, or by using advanced synthesizing technologies. The carbon family is very wide, it includes classical activated carbons to more advanced types like c...

Biodiesel is a clean burning fuel that can be obtainable from renewable sources and utilized in diesel vehicles. The physical characteristics of biodiesel are indistinguishable from petroleum diesel, therefore, it is currently considered as a best alternative fuel. However, the quality of the biodiesel is very important in order to commercialize an...

This chapter provides an overview of the use of nanoparticles in the biomedical field. Due to their unique properties, nanomaterials have enabled the development of innovative technologies within the biomedical field, making them a popular topic of research. Nanoparticles (NPs) can be prepared from a wide variety of materials and modified via a num...

Black TiO2 is capable to absorb the entire or part of the visible spectrum improving, a priori, the photoactivity under solar irradiation. Nevertheless, black TiO2 materials have not been able to demonstrate the expected photocatalytic activity in visible light due to the presence of a large number of recombination centers. In addition, high temper...

Chemically functionalized multi-walled carbon nanotubes (CNTs) are used as carriers for laccase immobilization. In this work, CNTs were modified using different approaches with a combination of methods involving hydrothermal oxidation with nitric acid, treatment with 3-aminopropyltriethoxysilane, glutaraldehyde, N-ethyl-N-(3-(dimethylamino)-propyl)...

Pristine nanodiamonds (NDs) obtained by detonation, or functionalized by different treatments, namely oxidation, hydrogenation and amination, were used to synthesize composites by insertion in TiO2 matrixes. The different treatments of the NDs lead to materials containing diverse texture properties and surface chemistry functionalities, particularl...

Carbon–phosphorus–titanium composites (CPT) were synthesized by Ti-impregnation and carbonization of cellulose. Microcrystalline cellulose used as carbon precursor was initially dissolved by phosphoric acid (H3PO4) to favor the Ti-dispersion and the simultaneous functionalization of the cellulose chains with phosphorus-containing groups, namely pho...

The effect of different membranes, membrane modules, feed temperatures, flow rates and solute concentrations on the permeate flux and salt rejection in direct contact membrane distillation (DCMD) was first studied with synthetic seawater and compared to distilled water. After optimizing these operating conditions, DCMD was tested with real feed sam...

Alternative composite materials with antibacterial activity have been developed by combining the porosity of carbon materials and the antibacterial activity of half sandwich (cymene)Ru-curcumin complexes. Different types of activated carbon were used, from commercial to synthetic and also ones derived from agricultural waste residues (almond shells...

Semiconductor photocatalysis has shown great potential as a low-cost, environmentally friendly treatment technology, and has undergone various developments in relation to its energy applications. Graphene, graphene oxide, reduced graphene oxide, and heteroatom-doped graphene have stimulated interest in the design of high-performance photocatalysts...

A series of Mo-doped carbon xerogels were obtained by surfactant-assisted sol-gel polymerization of resorcinol-formaldehyde at neutral pH. The morphology, porous texture, acid-base character and metal phase and dispersion, of these novel nanostructured materials were studied by several and complementary techniques, while their catalytic performance...

Different types of carbon-iron electro-catalysts have been prepared, exhaustively characterized, and tested as cathodes for the electro-catalytic reduction of CO2 at atmospheric pressure. Commercial iron and graphite sheets have also been tested as cathodes for comparison. All these electro-catalysts promoted the formation of C1 to C4 hydrocarbons...

Rising global energy demands associated to unbalanced allocation of water resources highlight the importance of water management solutions for the gas industry. Advanced drilling, completion and stimulation techniques for gas extraction, allow more economical access to unconventional gas reserves. This stimulated a shale gas revolution, besides tig...

Polysulfone (PSf) membrane supports were blended with pristine multi-walled carbon nanotubes (MWCTNs), functionalized MWCNTs (MWf), graphene oxide (GO) and their corresponding carbon-TiO2 composites. The surface hydrophilicity and the porous structure of the supports depended markedly on loading, type and surface chemistry of the nanostructured mat...

Este libro surge como compendio del material docente preparado en la planificación e impartición del Seminario Aplicaciones de adsorbentes y catalizadores en procesos medioambientales y energéticos. Este evento, propiciado por el Grupo Especializado de Adsorción de las RRSSEE de Física y Química como complemento de la XXXIX Reunión Ibérica de Adsor...

Among the available desalination technologies, membrane distillation (MD) is an emerging thermally driven process presenting several advantages compared to the current leading desalination technology, i.e., reverse osmosis (RO). Desalination of high-salinity brines and wastewaters are two of the many MD applications. However, high energy demand, ma...

Graphene-based membranes offer exciting opportunities for separation science due to their unique two-dimensional structure, outstanding mechanical strength, high permeance and selectivity. This Book Chapter summarizes the recent pro-gress in the design and fabrication of graphene-based membranes, such as na-noporous graphene membranes, free-standin...

Four magnetic carbon nanotube (CNT) samples (undoped, completely N-doped, and two selectively N-doped) were synthesized by chemical vapor deposition. The materials were tested in the catalytic wet peroxide oxidation (CWPO) of highly concentrated 4-nitrophenol solutions (4-NP, 5 g L−1). Relatively mild operating conditions were considered (atmospher...

Activated carbon based materials and more recently, nanostructured carbon materials namely, fullerenes, nanotubes, nanodiamonds and graphene, have been the focus of intensive research for application in nanotechnology. In the field of photocatalysis, carbon materials have been combined with conventional semiconductors as carbon/inorganic composites...

This work demonstrates the efficiency of a hybrid photocatalysis/ultrafiltration process to eliminate or reduce the contents of synthetic dyes in water. The process involves highly active photocatalytic ceramic ultrafiltration (UF) membranes prepared with the deposition of various photocatalysts on the external and internal (pore) surface of UF mon...

The photocatalytic degradation of a cyanobacterial toxin, microcystin-LA (MC-LA), was studied in aqueous solutions under both simulated solar light and visible light irradiation. Neat TiO2 and carbon-based TiO2 materials, prepared with carbon nanotubes (CNT) or graphene oxide (GO), were compared. The highest photocatalytic activity was obtained wit...

Flat sheet ultrafiltration (UF) membranes with photocatalytic properties were prepared with lab-made TiO2 and graphene oxide-TiO2 (GOT), and also with a reference TiO2 photocatalyst from Evonik (P25). These membranes were tested in continuous operation mode for the degradation and mineralization of a pharmaceutical compound, diphenhydramine (DP), a...

The catalytic combustion of volatile organic compounds (VOCs) is one of the most important techniques to remove these pollutants from the air stream, but it should be carried out at the lowest possible temperature, saving energy and avoiding the simultaneous formation of nitrogen oxides (NOx). Under these experimental conditions, the chemisorption...

Polyvinylidene fluoride (PVDF) flat sheet membranes were blended with multi-walled carbon nanotubes (MWCNTs) by the phase inversion method for direct contact membrane distillation (DCMD) of salty water (35 g L− 1 NaCl). The membrane properties and performances depended markedly on the synthesis parameters such as MWCNT loading, polyvinylpyrrolidone...

Owing to its unique electronic, optical, mechanical, and thermal properties, graphene is making a deep impact in many areas of science and technology. Graphene oxide (GO), produced directly from graphite through chemical oxidation with subsequent dispersion and exfoliation, has emerged as one of the most interesting derivatives of graphene. In part...