Articles publicats en revistes (Ciència dels Materials i Química Física)

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Magnetically-altered eg-orbital occupancy to boost the two-electron oxygen reduction electrocatalysis for faster water decontamination
(Elsevier B.V., 2025-02-11) Jing, Baojian; Zhang, Qingshan; Liu, Minghui; Yang, Shilin; Zhang, Jiayu; Qiu, Shan; Sirés Sadornil, Ignacio; Deng, Fengxia
Herein, we demonstrate how the magnetic modulation of the eg-orbital occupancy of Co ions can become a novel approach to enhance the two-electron oxygen reduction reaction (2e- ORR) for advanced wastewater treatment by electro-Fenton (EF) process. Nickel foam (NF) substrate coated with ZIF67 was prepared and thermally treated to obtain ferromagnetic NF-supported Co/Co3O4 cathodes, whose response to a small magnetic field was further evaluated in EF. The results show an increase of 62.3 % increase in H2O2 yield and 46.5 % in faradaic efficiency, improving the degradation rate of the antibiotic sulfamerazine from 77.2 % to 92.4 % in 120 min. This enhancement is attributed to improved electron transfer facilitated by the alteration of eg-orbital occupancy of Co ions caused by spin regulation under the magnetic field, rather than to mass transport effects. Therefore, magnetic modulation of the eg-orbital occupancy emerges as a promising strategy to boost EF process for more efficient water decontamination.
Complete antihistamine degradation in wastewater matrix using a metal-free N-doped carbon with superior electrocatalytic performance for in-situ $$H_2O_2$ production
(Elsevier B.V., 2025-01-11) Zhao, Lele; Mazzucato, Marco; Lanzalaco, Sonia; Parnigotto, Mattia; Cabot Julià, Pere-Lluís; Durante, Christian; Sirés Sadornil, Ignacio
A new gas-diffusion electrode (GDE) has been developed and optimized to apply the heterogeneous electro-Fenton (EF) process to the degradation of the antihistamine diphenhydramine. The complete removal of this hazardous drug pollutant was achieved within only 120 min in actual urban wastewater at pH 5.9. Nitrogendoped carbon electrocatalysts were first synthesized by direct pyrolysis of blends of commercial Vulcan carbon and melamine as nitrogen dopant. A radar chart was proposed to correlate the tested physicochemical and electrochemical properties. A well-balanced surface area, mesopores volume and defective carbon content were critical to ensure the highest activity (Eonset = 0.38 V vs. RHE) and selectivity (n ~ 2, yH2O2 ~ 95.3%) for twoelectron oxygen reduction reaction (ORR), which allowed the efficient in-situ production of H2O2 as •OH precursor. N-doping (10.5 wt%), along with the presence of pyrrolic N (3.5%), are also key factors to explain the enhancement. GDEs fabricated with the optimal electrocatalyst (71.4 wt% melamine content) were capable of accumulating up to ~35 mM H2O2 within 5 h, outperforming the commercial GDEs. This work evidences theinterplay of physicochemical and electrocatalytic parameters in H2O2-based advanced water treatment, demonstrating that it is possible to envisage a more efficient and greener tertiary wastewater treatment.
Rheological and morphological characterization of alternative solid particle materials for CSP applications
(Elsevier B.V., 2026-06-01) Díaz-Heras, M.; Majó, Marc; Calderón Díaz, Alejandro; Almendros-Ibáñez, J.A.; Barreneche, Camila
This study is focused on four residual materials, volcanic ashes (VA), flotation sterile (FS), ladle furnace slag (LFS) and black slags (BS) and their potential application as solid particles’ media in fluidized beds for thermal radiation processes. Although all materials fall within the Geldart B classification—indicating favorable fluidization behaviour—only two, FS and LFS, exhibited stable and complete fluidization. Detailed rheological and morphological analyses were conducted before and after exposure to radiation and fluidization, revealing no significant structural degradation. Minimum fluidization velocities were determined to assess flowability, leading to the exclusion of BS and VA materials despite their adequate physical and thermal properties. Between the two suitable candidates, LFS demonstrated a yield stress approximately 50% lower than that of FS, suggesting superior flowability and reduced mechanical resistance under non-confined conditions. However, LFS required a slightly higher minimum fluidization velocity (1.1 L/min more) due to its heterogeneous particle morphology. These findings highlight the potential of LFS as a cost-effective and flow-efficient medium for use in particle-based thermal energy storage systems.
Mechanical activation of halloysite as a sustainable precursor for cementitious materials
(Elsevier B.V., 2026-09-15) Marco-Gibert, Josep; Mañosa Bover, Jofre; Alvarez-Coscojuela, Adrian; Formosa Mitjans, Joan; Chimenos Ribera, Josep Ma.
This work presents a comprehensive investigation of the mechanical activation (MA) of halloysite (Hal) as a sustainable method to enhance its reactivity for the development of cementitious materials in construction applications. Hal, a 1:1 aluminosilicate clay with tubular morphology, is particularly valuable in regions where kaolinite (Kaol) is either scarce or entirely absent. High-energy planetary ball milling was applied to induce structural, morphological, and chemical modifications in a commercial Hal. The study systematically compares the effects of mechanical and thermal activation, employing a suite of advanced characterization techniques to monitor amorphization and microstructural changes. The most intensively milled sample (at 350 rpm for 120 min, H-350-120) reached 86% amorphous content, slightly higher than metahalloysite (MH, 84%). Reactivity was quantified using the modified Chapelle test, the R3 test, and alkaline solubility in 8 M NaOH. The H-350-120 sample achieved 1659 mg⋅g 1 of Ca(OH)2 fixation, 570 J⋅g 1 of cumulative heat release, and 10.98% bound water content, values closely comparable to those of MH. These findings enable the use of Hal-rich clays in regions with limited Kaol availability, and contributing to the development of supplementary or alternative cementitious materials.
Interfacially regulated hierarchical Ni-based electrodes for selective electrocatalytic hydrogenation of biomass-derived platform molecules
(Elsevier B.V., 2026-11-15) Vilariño Casaus, Pol; Gómez, Elvira; Serrà i Ramos, Albert; Tayyebi, Ebrahim; Exner, Kai S.; Montemo, Fatima
Electrocatalytic hydrogenation of biomass-derived oxygenates is limited by hydrogen evolution, acid-driven degradation of non-noble electrodes, and poor control of gas-evolving interfaces. Hierarchical Ni electrodes were prepared by dynamic hydrogen bubble templating on semiporous stainless steel and coupled with dodecyltrimethylammonium chloride (DTAC) interfacial regulation and Ru decoration. The macroporous, dendritic scaffold supports surface accessibility, reactant transport, and gas release, while DTAC attenuates unproductive proton reduction and improves structural persistence in acidic media. The platform was evaluated for levulinic acid (LA), 5-hydroxymethylfurfural (HMF), and furfural (FF), showing reactant-dependent selectivity. LA reduction was strongly temperature-dependent: 4-hydroxypentanoic acid-rich mixtures dominated at 5 °C, whereas γ-valerolactone (GVL) was favored at 50 °C, reaching 95.8% conversion, 88.7% Faradaic efficiency, and 92.6% GVL selectivity on DTAC-modified Ru-Ni A. HMF mainly yielded 2,5-bis(hydroxymethyl)furan, while FF gave furfuryl alcohol. Density functional theory calculations on clean Ni facets provide qualitative mechanistic context for possible surface-bound LA-to-GVL pathways and their sensitivity to surface geometry and reaction sequence.
Ir-based catalysts supported on Sn-doped titania nanotubes for the oxygen evolution reaction in acidic media
(Elsevier Ltd., 2026-02-01) Boter-Carbonell, Josep; Riba, Jordi; Cabot Julià, Pere-Lluís; Sarret i Pons, Maria; Teresa Andreu
The oxygen evolution reaction (OER) is sluggish in acidic media, such as in proton exchange water electrolysers, and demand highly active and stable catalysts. Ir-based materials offer excellent performance but are scarce and expensive, motivating efforts to reduce Ir loading while maintaining catalytic efficiency. In this work, Ir nanoparticles (NPs) were deposited via a microwave-assisted polyol method on previously synthesised anatase titania nanotubes (TNTs), doped with 3 at.% Nb or Sn, with a 40 wt.% Ir loading. TNTs were prepared hydrothermally, and structural characterization by Raman spectroscopy and XRD confirmed successful doping, although partial SnO₂ segregation was observed. XPS and Mott–Schottky analyses of the supports revealed the electron-donor character of the dopants, thus enhancing their electrical conductivity, especially in TNT–Sn. The well-dispersed Ir NPs 2 nm in size presented mixed oxidation states, including Ir⁰, IrOx, and IrO2, the first being dominant in Ir/TNT-Sn. The cyclic voltammograms after activation showed reversible redox Ir(III)/Ir(IV) transitions with flat peaks, shifted to more positive potentials than those of the reference Ir Black, indicating strong Ir–support interaction. The linear sweep voltammograms demonstrated the superior activity of the synthesised catalysts over Ir Black, with Ir/TNT–Sn showing the lowest overpotential, and the highest specific current density and turnover frequency. The better activity of the latter was attributed to the structural properties of the TNTs doped with Sn, which allowed increasing the support conductivity and facilitated an even stronger metal-support interaction.
Unravelling the oxygen reduction reaction selectivity of single-atom catalysts on N-doped graphene
(Elsevier Ltd., 2025-10-10) Shaldehi, Tahereh Jangjooye; Exner, Kai S.; Viñes Solana, Francesc; Illas i Riera, Francesc
A systematic investigation of the oxygen reduction reaction (ORR) under acidic conditions on a series of transition metal-based single-atom catalysts (SACs) on N-doped graphene is presented, focusing on the competing four-electron (4e⁻) and two-electron (2e⁻) pathways. The Gibbs adsorption free energy of key ORR intermediates is evaluated from density functional theory (DFT), and the potential-limiting steps and the corresponding limiting potentials are determined. For the 4e⁻ pathway, Co-based SACs exhibit the most favourable thermodynamic profile, with a thermodynamic overpotential of only 0.38 V, making it highly promising for complete oxygen reduction to water. Conversely, the 2e⁻ pathway leading to hydrogen peroxide (H2O2) production, is energetically favoured on Pt and Pd SACs. Notably, Ni and Cu SACs also demonstrate high selectivity toward the 2e⁻ mechanism but suffer from substantial overpotentials due to the sluggish *OOH reduction step towards H2O2. Activity trends were further assessed using the Gmax(U) descriptor, which quantifies the largest free energy span for each reaction pathway. The results reveal that while some SACs, such as Cu, exhibit potential for both ORR pathways, whereas Pt and Pd clearly favour the 2e⁻ pathway under acidic conditions. These findings offer valuable insights into the design of metal-specific SACs optimized for either complete ORR or selective H2O2 generation.
Transition metaldoped TiO₂ and CeO₂ photocatalysts modified with Ti₃C₂ MXene for PMS-driven advanced oxidation of pharmaceutical pollutants
(Elsevier B.V., 2025-09-26) Serafin, Jarosław; Bujaldón Carbó, Roger; Sreńscek-Nazzal, Joanna; Kałamagad, Agnieszka; Gómez, Elvira; Vendrell, Xavier; Serrà i Ramos, Albert
Pharmaceutical residues are increasingly persistent in aquatic environments due to their chemical stability andresistance to conventional wastewater treatment. To address this, we developed a two-step, performance-guidedsynthesis of TiO₂- and CeO₂-based photocatalysts: first doped with transition metals (Fe, Ni, Cu, Mo, Pd) andsubsequently modified with 2D Ti₃C₂ MXene to enhance peroxymonosulfate (PMS) activation under UV andvisible light. Among the dopants, Fe and Ni imparted the most favorable physicochemical features, includingnarrowed optical band gaps, increased oxygen vacancy concentrations, and reduced photogenerated chargerecombination, as evidenced by UV–vis, XPS, and photoluminescence analyses. Post-synthetic MXene integrationimproved interfacial charge separation and visible-light absorption, achieving >99 % total organic carbon (TOC)mineralization of a ternary pharmaceutical mixture (tetracycline, levofloxacin, and paracetamol) in real tapwater under UV irradiation. Comprehensive structural (XRD, Raman, TEM), optical (UV–vis DRS, PL), andsurface (XPS) characterizations identified the Ni–CeO₂–MXene composite as the most efficient, showing optimaldefect structure, redox activity, and electronic conductivity. The catalyst maintained >95 % activity over fivereuse cycles, with minimal leaching confirmed by ICP-OES. Post-reaction XPS revealed moderate surfacemodification (Ce4+/Ce3+ and Ni2+/Ni3+ ratios shift) without signs of structural degradation. Kinetic analysisconfirmed pseudo-first-order degradation with high rate constants and short half-lives, highlighting theirapplicability for rapid pharmaceutical mineralization. This study proposes a rational and selective approach forcoupling metal doping and 2D conductive interfaces, enabling the scalable design of stable and efficient photocatalystsfor PMS-driven advanced oxidation processes (AOPs) in water purification
Structural and electronic properties of MXene fakes: from edge e ects to bandgap evolution
(Royal Society of Chemistry, 2026-03-04) Allés, Miquel; Vela Llausi, Sergio; Morales García, Ángel; Viñes Solana, Francesc; Sousa Romero, Carmen
The structural and electronic properties of MXenes were investigated by means of a nite-systemapproach using all-electron Density Functional Theory-based calculations. Pristine (M2C)n akes and theirO-terminated counterparts (M2CO2)n (M = Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W; 12 ≤ n ≤ 216) werecomputationally modelled. Surface-like behaviour is lost for n ≤ 90, corresponding to ca. 3 nm wideakes, where nite-size e ects become increasingly relevant. While the ake structure at the core is verysimilar to that found in extended periodic models, the edges are often deformed due to structuraldefects, which impact their electronic properties. Pristine M2C akes are metallic, while the O-terminatedM2CO2 counterparts present bandgaps exceeding 1 eV for metals of Groups III and IV when neglectinglow-populated gap states near the Fermi level. The alignment of the valence and conduction bands forthese systems evolves favourably to nearly include the water splitting half-reactions within the bandgapfor the largest akes. Overall, our results show that Sc, Y, Zr, and Hf O-functionalised MXenes are the bestsuited for photocatalytic water splitting, obtaining energy gaps within the visible spectrum for severalflake sizes, and band alignments closer to water oxidation and hydrogen reduction reactions.
Environmental assessment of volcanic-ash-based alkali-activated binders: Oxyanion leaching and marine bioassay responses
(Elsevier Ltd., 2026-04-13) Muñoz-Ruiz, Victoria; Santos, Jorge; Mañosa Bover, Jofre; Cifrian, Eva; Pérez-Gandarillas, Lucía; Chimenos Ribera, Josep Ma.; Andrés, Ana
Volcanic ash (VA) from the 2021 Tajogaite eruption (La Palma, Spain) is a high-volume aluminosilicate residue with potential for low-carbon construction materials, yet its environmental behaviour remains insufficiently characterised. This study evaluates VA-based alkali-activated binders (AABs) through standardized leaching tests UNE-EN 12457–4 (UNE, 2003), ICP-MS trace-element quantification, and two marine bioassays: the Vibrio f ischeri luminescence inhibition test (ISO 11348-3:2007) and the Paracentrotus lividus embryo–larval development test. Activation with 6 M and 8 M NaOH substantially modified the geochemical release profile of the precursor, increasing pH, conductivity, and the mobilisation of oxyanion-forming elements (As, Mo, V). Mo exceeded EU inert-landfill limits, while Sb and Se approached regulatory thresholds. Seawater extractants buffered alkalinity but did not suppress oxyanion release, indicating that high ionic strength maintains MoO₄ and VO₄ 3 2 solubility. The consistent release hierarchy (V > Mo > As) highlights the role of alkali-driven speciation. Bioassays showed marked taxon–specific sensitivity. V. fischeri classified all eluates as non-toxic (LID ≤8; TU < 0.4), suggesting limited acute effects on bacterial metabolism. Conversely, P. lividus exhibited significant sublethal toxicity, especially for the 8 M binder (EC 50 = 56.90%), with developmental inhibition correlating with elevated oxyanion concentrations. These results demonstrate that VA-based AABs are technically viable but exhibit activation-dependent environmental behaviour that is not detected by bacterial assays alone. Results support integrating sensitive marine invertebrate bioassays into regulatory and weight-of-evidence frameworks and provide guidance for the sustainable management of volcanic residues and the deployment of alkali-activated materials in coastal and marine-influenced environments.
Atomically-dispersed transition metal electrocatalysts supported on lignin-derived carbons for cathodic hydrogen peroxide synthesis using a gas-diffusion electrode
(Elsevier B.V., 2026-05-14) Zuccante, G.; Escaja Sánchez, Nuria; Sirés Sadornil, Ignacio; Muhyuddin, Mohsin; Santoro, Carlo
Hydrogen peroxide (H2O2) is nowadays a commodity chemical, with a particularly relevant application in wastewater treatment. However, its industrial production is energy demanding, highly polluting and potentially dangerous. Lately, oxygen reduction reaction (ORR) conducted on a gas-diffusion electrode (GDE) has been explored to deploy a more sustainable synthesis route. In this work, a set of lignin-derived carbons, either metal-free or loaded with atomically dispersed transition metals (Fe, Co and Ni), was successfully synthesized for the electrogeneration of H2O2. For some electrocatalysts, the rotating ring-disk electrode (RRDE) analysis showed a peroxide selectivity () over 90% and a number of transferred electrons of ∼2. Accordingly, the type of metal and the carbon porosity had a major influence on the performance of GDEs during bulk electrolysis. In galvanostatic assays conducted in 0.05 M Na2SO4 medium at pH 5.9 and 10 mA cm−2, the carbon obtained from direct lignin pyrolysis at 400 °C outperformed a commercial GDE, showing the highest H2O2 yield (13.8 mM after 360 min), with a maximum current efficiency of 85% and relatively low energy consumption (∼ 8 ). Such optimum performance is related to its optimal porosity and hydrophobicity. Moreover, upon functionalization with Fe, an effective electro-Fenton (EF) catalyst was obtained, allowing a 97% removal of the drug lisinopril using only 0.1 g L−1 of suspended catalyst. This work demonstrates the possibility of producing cost-effective electrocatalysts from waste for H2O2 production and wastewater treatment.
Evaluating the stability and efficiency of Fe(III)-DTPA complex for prednisolone degradation by solar photoelectro-Fenton process at neutral pH
(Elsevier B.V., 2026-07-17) Tirira, Paola; Díaz Redondo, Ivan; Lopez Vinent, Nuria; Zhou, Minghua; Cabot Julià, Pere-Lluís; Sirés Sadornil, Ignacio
The stability of the Fe(III)-DTPA complex for its use as a promising homogeneous catalyst to solve the pH bottleneck in solar photoelectro-Fenton (SPEF) process was evaluated for the first time. Viability depends on its resistance to photodegradation and attack by reactive oxygen species; ideally, it should allow sufficient release of free iron catalyst while preserving ligand stability to prevent iron precipitation. Here, Fe(III)-to-ligand molar ratio was first optimized to ensure complete chelation within a wide pH range, as well as high photostability against UVA and sunlight and resistance to •OH attack. Results showed that Fe(III)-DTPA complex at ratios of 1:1 and 1:2 remained stable at pH 3–9 for at least 180 min. Notably, the 1:2 complex exhibited superior photostability and oxidative resistance during SPEF treatment, minimizing the iron precipitation. As a proof of concept, removal of the glucocorticoid prednisolone (PREDN) by SPEF at pH 7 was investigated. Complete degradation of 0.055 mM PREDN in 50 mM Na2SO4 medium containing 0.05 mM Fe(III)-DTPA (1:2) was achieved after 90 min at 30 mA cm−2. Although 95% of the complex was also degraded, the organic species derived from iron complex maintained a significant percentage of soluble iron (> 40%). Additionally, phytotoxicity and QSAR tests revealed that an initially pronounced toxicity due to by-products generated from DTPA and PREDN resolved into a non-toxic mixture with enhanced biodegradability. Therefore, Fe(III)-DTPA complex (1:2) can be considered a sustainable catalyst for SPEF treatment of drugs at circumneutral pH, combining acceptable operational stability and environmental safety.
Potential use of municipal solid waste incineration bottom ash as supplementary cementitious materials based on particle size fraction.
(Springer Verlag, 2026-04-11) Marco‑Gibert, J.; Cuspoca, Fabian; Córdoba, Javier C.; Pujadó López, Nil; Mañosa Bover, Jofre; Faneca, Gerard; Chimenos Ribera, Josep Ma.
Incinerator bottom ash (IBA) is a heterogeneous by-product mainly composed of mineral phases. Despite its variable composition, it is generally classified as a silica-rich secondary raw material, containing significant amounts of aluminium, calcium, and amorphous phases. These characteristics make IBA a potential candidate for use as a supplementary cementitious material (SCM) in blended cement formulations. However, due to its heterogeneity, evaluating the behaviour of different particle size fractions is essential to ensure consistent performance. In this study, the pozzolanic activity of various IBA fractions was assessed using three standard reactivity tests: the modified Chapelle test, the modified R3 test, and the strength activity index (SAI). The results varied depending on the test applied, but a general trend was observed in which coarser fractions exhibited greater pozzolanic activity than finer ones. The fraction larger than 8 mm consistently showed the best performance across all tests. Additionally, the environmental impact of each fraction was analysed through batch leaching tests to determine the potential release of metal(loid)s. Regarding environmental safety, leaching results confirmed that all particle size fractions met the requirements to be classified as non-hazardous at the end of their life cycle. These findings support the use of IBA, particularly its coarser fractions, as a sustainable and safe SCM in the production of blended cement.
Decoding Solvent Effects in Electrocatalytic Biomass Valorization: Levulinic Acid to γ-Valerolactone
(American Chemical Society, 2026-04-08) Vilariño Casaus, Pol; Bautista, Queralt; Gómez, Elvira; Serrà i Ramos, Albert
Electrocatalytic hydrogenation (ECH) of biomass-derived levulinic acid (LA) offers a sustainable route to prepare γ-valerolactone (GVL), a versatile green solvent and fuel additive. Yet despite its promise, most studies overlook the decisive role of the solvent environment, conflating conversion with true product yield. Here we disentangle these effects by systematically probing LA reduction over GC, Cu, Ni, and CuNi cathodes in three contrasting solvents (MeOH, DMSO, IPA) at two temperatures (15 and 35 °C). A clear design rule emerges: the solvents dictate the conversion ceiling, while temperature gates selectivity. At 15 °C, LA consumption is observed but productive lactonization toward GVL remains “off”, yielding only traces of HVA. At 35 °C, lactonization is unlocked, enabling GVL selectivity’s >90% in MeOH with metal-earth-abundant, Ni-based catalysts. Solvent characterization (viscosity, dielectric constant, ionic conductivity) combined with DFT analysis provides a direct rationale for the experimental trends. Methanol emerges as the most effective medium, consistent with its low viscosity and high electrolyte conductivity, which together mitigate diffusion and iR penalties relative to IPA and DMSO. DMSO shows intermediate performance, consistent with strong solvation/dielectric stabilization of intermediates, whereas IPA combines high viscosity and low ionic mobility, leading to the lowest conversions. Overall, efficient LA-to-GVL ECH is not dictated by conversion alone but by the coupled interplay of solvent properties, catalyst identity, and temperature required to link surface hydrogenation with thermally assisted lactonization.
The role of D-glucose in prolonging the lifetime of indium inalkaline cyanide electrolytes
(Elsevier, 2026-06-14) Amazian el Moussaoui, Mohamed; Vela Llausí, Sergi; Madurga Díez, Sergio; Sarret i Pons, Maria; Andreu Arbella, Teresa
Indium is commonly used in various environmental solutions due to its unique properties. However, in the electrodeposition of decorative AuCuIn alloys, its stability in aqueous cyanide solutions is a challenge because it tends to precipitate as In(OH)3. Previous studies have suggested the use of D-glucose in cyanide media to stabilize the solution. However, the lifespan of the solution remains quite short, and the complexes formed in the solutions, as well as the stabilizing mechanism of D-glucose, are unknown. This work investigates the effect of adding D-glucose to stabilize indium salts in cyanide media using experimental data and computational simulations. The reduction of free cyanides in the presence of D-glucose assessed the transformation of D-glucose into D-glucocyanohydrin (DGluCN) in alkaline media. Molecular dynamics simulations showed that the presence of DGluCN decreases the number of intermolecular collisions of indium complexes (In(OH)3 or In(CN)3) at short distances, thereby preventing its precipitation and allowing the species formed by In3+ to remain stable in the solution in their colloidal form. These findings provide a deeper understanding of indium kinetic stabilization at alkaline pH, which could potentially expand the application fields of this metal.
Chlorophyll-derived Fe-sensitized TiO2 for visible light-driven photocatalytic degradation of a pesticide
(Elsevier Ltd., 2026-06-27) Lauer Albornoz, L.; Brillas, Enric; Sirés Sadornil, Ignacio; Lanzalaco, Sonia; da Silva, Salatiel W.; Bernardes, Andrea M.
This study investigates chlorophyll-derived Fe-sensitized TiO2 photocatalysts for visible light-assisted degradation of the persistent fungicide prochloraz (PCZ) employing simulated solar irradiation. Chlorophyll-derived Fe complexes extracted from Ceratophyllum submersum were immobilized onto sol–gel-derived TiO2 nanoparticles at different loadings (1–5 wt%) through a solution-based assembly protocol involving sonication, freeze-drying, washing, and desiccation. The obtained materials were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, diffuse reflectance spectroscopy, and zeta potential analyses to evaluate their structural, morphological, and optical properties. Photocatalytic experiments were performed under simulated sunlight using aqueous PCZ solutions at pH 7.0. The results demonstrated that TiO2/Chl–Fe(1%) achieved near-complete PCZ degradation (>98%) within 60 min, significantly outperforming pure TiO2. However, TOC removal remained partial, indicating that pollutant transformation predominated over complete mineralization. The enhanced photocatalytic performance was associated with improved visible-light harvesting promoted by chlorophyll-derived surface sensitization. The TiO2/Chl–Fe(1%) catalyst exhibited the highest photocatalytic activity, whereas increasing Chl–Fe loading above TiO2/Chl–Fe(1%) did not lead to further performance enhancement, likely due to partial aggregation of the sensitizer and reduced light-harvesting efficiency. These findings demonstrate that chlorophyll-mediated Fe sensitization effectively improves the photocatalytic activity of TiO2 under visible light and environmentally relevant conditions without requiring acidic pH adjustment. The proposed system represents a promising visible-light-responsive photocatalytic approach for pesticide transformation in contaminated water.
Solar photo-thermocatalytic valorization of biomass waste to biofuel precursors using inexpensive Ni–P/graphite catalysts
(Elsevier B.V., 2026-10-01) Rigual Miret, Jordi; Fons, Arnau; Nogués, Josep; Esplandiu, María J.; Gómez, Elvira; Sepúlveda, Borja; Serrà i Ramos, Albert
Developing efficient, low-cost catalytic routes for biomass upgrading for sustainable fuel and chemical production is a crucial step toward a greener society and circular economy. Ni–P/graphite catalysts prepared by electroless deposition on graphite microflakes were used for photo-thermocatalytic transfer hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) in isopropanol, without external H2 or noble metals. Graphite provides broadband optical absorption and localized heat generation; the Ni–P coating supplies the active hydrogen-transfer sites, with isopropanol serving as hydrogen donor. Under near-infrared laser irradiation at 105 °C, complete LA conversion was achieved in 120 min, 2.5-fold faster than the solvothermal process at the same temperature. Solar-driven tests using a parabolic concentrator (105 °C, 2.5 mg mL−1, 100 mL scale) yielded 99.1% GVL after 80 min; over-reduction to valeric acid became significant only at 120 min. The catalyst retained near-quantitative activity over five consecutive cycles with negligible cumulative Ni and P leaching. Tests with a synthetic biomass hydrolysate approximating wheat-derived acid hydrolysate composition (LA/furfural/formic acid, 104:1:36 M ratio) showed LA conversion exceeding 99.9% at 40 min and complete furfural conversion by 80 min. The furfural hydrogenation network yielded furfuryl alcohol, 2-methylfuran, tetrahydrofurfuryl alcohol, and 2-methyltetrahydrofuran (23.2% at 120 min). Formic acid decomposition supplemented isopropanol as hydrogen donor under mixed-feed conditions. The optimal catalyst loading of 2.5 mg mL−1 was 36-fold lower than the Raney Ni dose required for comparable photo-thermocatalytic LA conversion, which additionally demanded a reaction temperature of ca. 130 °C.
Bioinspired hierarchical electrospun TiO2/BiOI nanofibers for multifunctional photocatalytic PMS activation: Antibiotics and microplastics removal
(Elsevier Ltd., 2026-10) Huidobro, Laura; Abid, Mahmoud; Bechelany, Mikhael; Gómez, Elvira; Serrà i Ramos, Albert
Emerging antibiotics and microplastics are poorly removed by conventional treatment processes, requiring oxidation processes that address both dissolved and particulate contaminants. Hierarchical electrospun TiO2/BiOI nanofibers (TBO1–TBO4; BiOI growth 2–16 h) were engineered for photocatalytic peroxymonosulfate (PMS) activation under UV-A (365 nm) and visible light. At pH 7 and 20 °C (sulfamethoxazole, SMX, 5 ppm; catalyst 0.50 g L−1; PMS 2.5 mM), TBO3 achieved near-complete, blank-corrected total organic carbon (TOC) removal (≥99%) in 120 min under visible light + PMS. For a four-component multipollutant solution (20 ppm total), TBO3 reached near-complete TOC removal after blank correction (reported as ≥99%, with residual TOC close to the method quantification limit) in 120 min and maintained activity over nine cycles under visible light + PMS (≤0.7 %age-point change; leaching below detection), whereas UV-A + PMS decreased to 85.3% by cycle 9 with ppb-level leaching. Quenching and probe assays indicate a radical-accessible PMS-assisted oxidation network; strong suppression by tert-butanol and methanol supports major •OH-accessible oxidation with a sulfate-radical-type contribution. Under visible light (465–470 nm) + PMS, cross-linked polystyrene (PS) microplastics (20 ppm solids) underwent surface erosion, cracking, delamination, and fragmentation, accompanied by release of dissolved/sub-10 μm carbonaceous products in scaled-up tests, supporting partial oxidative transformation of particulate microplastics.
On the performance of wood waste-derived gas-diffusion electrodes in a filter-press cell: H2O2 electrogeneration and antibiotic removal at neutral pH
(Elsevier Ltd., 2026-06-25) Tirira Arteaga, Paola Cecilia; Petsi, Panagiota; Zhao, Lele; Sirés Sadornil, Ignacio; Plakas, Konstantinos V.
Lately, several strategies have been developed for H2O2 synthesis from 2e− oxygen reduction reaction (ORR), motivated by the growing industrial relevance of this chemical. Nonetheless, the design of sustainable and cost-effective methods for large-scale H2O2 electrosynthesis remains elusive. In this context, biomass-derived carbon has emerged as an environmentally friendly alternative to conventional carbon black. Here, commercial wood waste-derived biochar exhibited a 2e− ORR selectivity over 60% at neutral pH. Gas-diffusion electrodes (GDEs) prepared with this electrocatalyst were evaluated in undivided filter-press cells at two operational scales (0.5 L and 2.5 L). The results showed substantial H2O2 production and remarkable operational stability over 10 consecutive 1-hour cycles. Sulfadoxine (SDX) was selected as a model organic pollutant to assess the performance of the new GDEs in photoelectro-Fenton (PEF) process. A commercial Fe(III)-DTPA fertilizer was employed as the catalyst to enable effective performance at neutral pH, achieving the complete removal of 5 mg L−1 SDX at 20 mA cm−2 after 45 min at pre-pilot scale. A plausible degradation pathway was proposed based on five identified transformation by-products. Likewise, a preliminary economic assessment indicated that the greener GDEs are potentially competitive as compared to electrodes made with carbon black. Overall, our work offers a sustainable pathway for advanced oxidation of pharmaceuticals at neutral pH.
Quatsome nanovesicles as antibacterial platform: Mechanistic insights into their activity against planktonic and biofilm Staphylococcus aureus
(Elsevier B.V., 2026-06-26) Korber, Mariana; Gallardo Moreno, Amparo M.; Ferrer Tasies, Lidia; Fernández Calderón, Maria Coronada; Pujol Solé, Nuria; Tomsen Melero, Judit; Guasch, Elba; Tamurejo Alonso, Purificación; Mitjans Arnal, Montserrat; Vinardell, María Pilar; Domingo Tafalla, Beatriu; Giannotti, Marina Inés; Rancan, Fiorenza; Schaudinn, Christoph; Veciana, Jaume; Ratera, Imma; Roldán, Mónica; González Mira, Elisabet; González Martín, María Luisa; Ventosa, Nora
The growing threat of antibiotic-resistant pathogens has intensified the demand for alternative antibacterial materials. Quatsomes-nanovesicles composed of cholesterol and quaternary ammonium surfactants (QAS)- emerge as promising candidates due to their intrinsic antimicrobial properties and tunable physicochemical characteristics. Here, we investigate the antibacterial activity of quatsomes incorporating QAS with either tetradecyl (C14) or hexadecyl (C16) alkyl chains against Staphylococcus aureus, a leading cause of hospital-acquired infections. Both quatsome types exhibited potent bactericidal activity in planktonic cultures, with C16containing formulations showing a 2.5-fold lower minimum bactericidal concentration than C14 counterparts. Confocal microscopy suggested a partial penetration of cationic quatsomes into the bacterial peptidoglycan layer, accompanied by significant increases in zeta-potential, suggesting strong electrostatic interactions without visible membrane disruption, as confirmed by scanning electron microscopy. Both formulations also demonstrated high efficacy against mature S. aureus biofilms, with no significant differences between alkyl chain lengths, indicating a mechanism primarily targeting the extracellular biofilm matrix. In addition, they showed a good antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). A preliminary safety assessment using reconstructed human epidermis (EpiskinTM) confirmed the non-irritant nature of both formulations. These findings highlight the potential of QAS-based quatsomes as effective and biocompatible nanocarriers for topical antibacterial applications, offering a promising platform for combating antibiotic-resistant infections in both planktonic and biofilm states.

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