Coelectrolysis of PET and CO2Using an Electrochemically Restructured Co-MOF-74 Anode and a Polymeric Co-Phthalocyanine Cathode Raúl Rojas-Luna, Lewis S. Cousins, Rhiannon Germaney, Dolores G. Gil-Gavilán, Miguel Castillo-Rodríguez, Dora-Alicia Garcia Osorio, Thomas Doughty, Dolores Esquivel, Charles E. Creissen, Souvik Roy ACS Applied Materials and Interfaces, 2026 High Resolution Image Download MS PowerPoint Slide Mitigating carbon emissions and plastic waste is a pressing societal challenge due to the disruptive environmental impact of incremental accumulation. A promising strategy to address both issues is coelectrolysis of CO 2 and PET-plastic waste to high-value commodity chemicals. Here, we report electrocatalytic upcycling of polyethylene terephthalate (PET) plastic to formate and terephthalic acid using a cobalt-based metal–organic framework (Co-MOF-74). The electrocatalyst underwent oxidative restructuring to cobalt oxyhydroxide under operating conditions and exhibited near-unity faradaic efficiency (FE) for the ethylene glycol oxidation reaction (EGOR) to formate during short-term electrolysis. Notably, EGOR required 0.23 V lower potential compared to the conventional oxygen evolution reaction (OER) at a current density of 100 mA cm –2 . When coupled with a CO 2 reducing cathode, a maximum combined FE of 156% was achieved for formate (anode) and syngas (cathode) at a cell voltage ( E cell ) of 1.6 V. Upon integration of the EGOR electrode in a CO 2 -fed flow cell, the coupled system required an E cell of ∼2.3 V to operate at 75 mA cm –2 . This work presents a promising integrated approach that offers a compelling solution for mitigating environmental pollution by enabling the electrochemical reforming of CO 2 and plastic waste into valuable chemicals under cost-effective and energy-efficient conditions.
Zn-Cr LDH/Graphene Oxide Composites for Selective Photocatalytic CO2 Reduction toward CO under Visible Light Irradiation Dolores G. Gil-Gavilán, Raúl Rojas-Luna, Juan Amaro-Gahete, Daniel Cosano, Miguel Castillo-Rodríguez, Dolores Esquivel, Souvik Roy, José R. Ruiz, Francisco J. Romero-Salguero Energy and Fuels, 2025 The direct conversion of solar energy to chemical energy represents a substantial scientific challenge in contemporary society. The levels of carbon dioxide (CO 2 ), the main gas responsible for the greenhouse effect, are increasing. Consequently, there is growing interest in the photocatalytic transformation of CO 2 into valuable products to reduce its environmental impact. In this context, sunlight, as a clean and sustainable energy source, is harvested for CO 2 photoreduction (CO 2 PR). Additionally, high selectivity for carbon monoxide (CO) may be desirable because it can be further converted via well-known processes into chemical fuels such as methanol, hydrogen, or liquid hydrocarbons. Layered double hydroxides (LDH) are excellent candidates as catalysts due to their unique layered structures and redox activity. In the past decade, scientists have endeavored to improve the properties of LDH to increase the overall efficiency of CO 2 conversion. In this work, Zn–Cr LDH and their composites with graphene oxide (GO) were prepared by a coprecipitation method, characterized by different techniques, and tested as catalysts in a three-component system using [Ru(bpy) 3 ] 2+ as a photosensitizer (PS) and triethanolamine (TEOA) as a sacrificial electron donor (ED). This is the first use of Zn–Cr LDH/GO composites as catalysts in CO 2 PR under visible light irradiation. The results were outstanding (13,933 μmol of CO g –1 at 24 h). The amount of GO in the composite is crucial to achieve a synergistic effect with the LDH, resulting in an increased efficiency in the photoreduction of CO 2 to CO.
Visible-Light-Driven Photocatalytic H2 Production Using Composites of Co-Al Layered Double Hydroxides and Graphene Derivatives Dolores G. Gil-Gavilán, Juan Amaro-Gahete, Daniel Cosano, Miguel Castillo-Rodríguez, Gustavo de Miguel, Dolores Esquivel, José R. Ruiz, Francisco J. Romero-Salguero Inorganic Chemistry, 2024 The direct conversion of solar energy into chemical energy represents an enormous challenge for current science. One of the commonly proposed photocatalytic systems is composed of a photosensitizer (PS) and a catalyst, together with a sacrificial electron donor (ED) when only the reduction of protons to H2 is addressed. Layered double hydroxides (LDH) have emerged as effective catalysts. Herein, two Co-Al LDH and their composites with graphene oxide (GO) or graphene quantum dots (GQD) have been prepared by coprecipitation and urea hydrolysis, which determined their structure and so their catalytic performance, giving H2 productions between 1409 and 8643 μmol g-1 using a ruthenium complex as PS and triethanolamine as ED at 450 nm. The influence of different factors, including the integration of both components, on their catalytic behavior, has been studied. The proper arrangement between the particles of both components seems to be the determining factor for achieving a synergistic interaction between LDH and GO or GQD. The novel Co-Al LDH composite with intercalated GQD achieved an outstanding catalytic efficiency (8643 μmol H2 g-1) and exhibited excellent reusability after 3 reaction cycles, thus representing an optimal integration between graphene materials and Co-Al LDH for visible light driven H2 photocatalytic production.
Zn-Cr Layered Double Hydroxides for Photocatalytic Transformation of CO2 under Visible Light Irradiation: The Effect of the Metal Ratio and Interlayer Anion Dolores G. Gil-Gavilán, Daniel Cosano, Juan Amaro-Gahete, Miguel Castillo-Rodríguez, Dolores Esquivel, José R. Ruiz, Francisco J. Romero-Salguero Catalysts, 2023 Carbon dioxide is the main gas responsible for the greenhouse effect. Over the last few years, the research focus of many studies has been to transform CO2 into valuable products (CO, HCOOH, HCHO, CH3OH and CH4), since it would contribute to mitigating global warming and environmental pollution. Layered double hydroxides (LDHs) are two-dimensional materials with high CO2 adsorption capacity and compositional flexibility with potential catalytic properties to be applied in CO2 reduction processes. Herein, Zn-Cr LDH-based materials with different metal ratio and interlayer anions, i.e., chloride (Cl−), graphene quantum dots (GQDs), sodium dodecyl sulfate (SDS) and sodium deoxycholate (SDC), have been prepared by a co-precipitation method and characterized by different techniques. The influence of the interlayer inorganic and organic anions and the metal ratio on the application of Zn-Cr LDHs as catalysts for the photocatalytic CO2 reduction reaction under visible light irradiation is unprecedentedly reported. The catalytic tests have been carried out with Ru(bpy)32+ as photosensitizer (PS) and triethanolamine as sacrificial electron donor (ED) at λ = 450 nm. All LDHs materials exhibited good photocatalytic activity towards CO. Among them, LDH3-SDC showed the best catalytic performance, achieving 10,977 µmol CO g−1 at 24 h under visible light irradiation with a CO selectivity of 88%. This study provides pertinent findings about the modified physicochemical features of Zn-Cr LDHs, such as particle size, surface area and the nature of the interlayer anion, and how they influence the catalytic activity in CO2 photoreduction.
Insights into laser powder bed fused Scalmalloy®: investigating the correlation between micromechanical and macroscale properties Shawkat Imam Shakil, Leandro González-Rovira, Leticia Cabrera-Correa, Juan de Dios López-Castro, Miguel Castillo-Rodríguez, F. Javier Botana, Meysam Haghshenas Journal of Materials Research and Technology, 2023 Additively manufactured Scalmalloy® using laser powder bed fusion (LPBF) has been showing increasing potential for industrial adoption. Its intended application in space, aerospace, and automotive industries requires extensive testing and characterization to produce parts with repeatable properties and safe operations. In the present paper, a thorough investigation of the association between small-scale (micro/nano-scale) and macro-scale (e.g., tensile) properties and microstructural features has been conducted. The prime novelty is the correlation of the small-scale hardness with the tensile properties, which is studied in both as-built and heat-treated conditions (325°C/4 h) along parallel and perpendicular build directions of the samples. Advanced microstructural characterization including scanning and transmission electron microscopies (SEM/TEM), as well as electron backscatter diffraction (EBSD), was carried out on each condition to correlate microstructure and mechanical properties. While significant improvement in strength was found from as-built to heat-treated conditions, due to the precipitation of secondary Al3Sc and Al3(Sc, Zr), grain size or texture did not change considerably. The grain size analysis revealed a fine-grained zone (FGZ: mostly between 0.5-1 μm) next to the coarse-grained zone (CGZ: mostly between 2-15 μm). All samples show texture-free FGZ and textured CGZ with a predominance of <001> crystal directions parallel to the building direction.
Composites of Co-Al hydrotalcites and carbon nanomaterials for photocatalytic H2 production Dolores G. Gil-Gavilán, Daniel Cosano, Miguel Castillo-Rodríguez, Gustavo de Miguel, Dolores Esquivel, César Jiménez-Sanchidrián, José R. Ruiz, Francisco J. Romero-Salguero Applied Clay Science, 2023 Hydrogen is considered one of the main energy sources for the near future. Numerous efforts are currently underway for the direct transformation of solar energy into H2. Hydrotalcites are two-dimensional materials whose composition can be tuned relatively easily and, by themselves or in combination with other materials, are proving to be useful for the H2 evolution reaction. In this work, composites of a Co-Al hydrotalcite with carbon spheres or nanotubes have been prepared. It has been shown that, in general, such composites improve H2 production. The influence of the nature, structure, and characteristics of the different materials on the reaction has been studied, as well as the role of each component and its mechanism. In particular, proper integration of both components and improved textural properties, as is the case of the composite with carbon spheres, leads to a yield of 3820 μmol H2 g−1 at 5 h, more than twice that obtained with hydrotalcite alone, in the presence of Ru(bpy)3Cl2 as a photosensitizer and triethanolamine as an electron donor at 450 nm. The present methodology opens the door to the preparation of other composites for the improvement of the performance of photocatalytic systems for H2 production.
Visible-light-harvesting basolite-A520 metal organic framework for photocatalytic hydrogen evolution Raúl Rojas-Luna, Juan Amaro-Gahete, Dolores G. Gil-Gavilán, Miguel Castillo-Rodríguez, César Jiménez-Sanchidrián, José Rafael Ruiz, Dolores Esquivel, Francisco José Romero-Salguero Microporous and Mesoporous Materials, 2023 A heterogeneous photosensitizer [email protected] has been successfully synthesized following an unprecedented strategy based on the incorporation of surface dipyridyl-dihydropyridazine adducts by Diels–Alder reaction on the aluminum fumarate units of the highly porous metal-organic framework (MOF) BASF-A520 and their further coordination to ruthenium metal centers. The characterization of the resulting metal-organic framework, including the ruthenium bipyridine-like photosensitizer moieties attached to its linkers, has been carried out by a wide variety of techniques, such as X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherms, solid-state cross-polarization magic angle spinning carbon-13 nuclear magnetic resonance (13C CP/MAS NMR), X-ray photoelectron spectroscopy (XPS) and ultraviolet–visible (UV–vis) spectroscopy. The light absorption in the visible region shown by the resulting material, [email protected], has allowed its application as a single-site solid photosensitizer for photochemical reactions of hydrogen evolution in conjunction with Pt nanoparticles as catalyst, EDTA as sacrificial electron donor and MV as electron carrier. A remarkable photocatalytic activity after 72 h was achieved, with a TON of 1157 based on the heterogeneous ruthenium photosensitizer, in aqueous solution at pH 5.0, which confirmed the effective stabilization of the ruthenium dipyridyl-dihydropyridazine adducts on the MOF surface and the efficient electron injection from the photoexcited [email protected] to Pt nanoparticles mediated by MV electron carrier for hydrogen generation from water.
Mechanical behavior of in P Twinning Superlattice Nanowires Zhilin Liu, Ioannis Papadimitriou, Miguel Castillo-Rodríguez, Chuanyun Wang, Gustavo Esteban-Manzanares, Xiaoming Yuan, Hark H. Tan, Jon M. Molina-Aldareguía, Javier Llorca Nano Letters, 2019
Adhesion enhancement of DLC hard coatings by HiPIMS metal ion etching pretreatment J.A. Santiago, I. Fernández-Martínez, A. Wennberg, J.M. Molina-Aldareguia, M. Castillo-Rodríguez, T.C. Rojas, J.C. Sánchez-López, M.U. González, J.M. García-Martín, H. Li, V. Bellido-González, M.A. Monclús, R. González-Arrabal Surface and Coatings Technology, 2018
Microstructure and high temperatures mechanical properties of liquid-phase-sintered α-SiC with Y2O3-Al2O3 additions Boletin De La Sociedad Espanola De Ceramica Y Vidrio, 2005
