Carlos R. Cabrera

University of Texas at El Paso | UTEP · Department of Chemistry and Biochemistry

An autonomous electrochemical system prototype for ammonia oxidation reaction (AOR) measurements was efficiently done inside a 4'' x 4'' x 8'' 2U Nanoracks module at the International Space Station (ISS). This device, the Ammonia Electrooxidation Lab at the ISS (AELISS), included an autonomous electrochemical system that complied with NASA ISS nond...

Designing N-coordinated porous single-atom catalysts (SACs) for the oxygen reduction reaction (ORR) is a promising approach to achieve enhanced energy conversion due to maximized atom utilization and higher activity. Here, we report two Co(II)-porphyrin/ [2,1,3]-benzothiadiazole (BTD)-based covalent organic frameworks (COFs; Co@rhm-PorBTD and Co@sq...

Urea synthesis through the simultaneous electrocatalytic reduction of N2 and CO2 molecules under ambient conditions holds great promises as a sustainable alternative to its industrial production, in which the development of stable, highly efficient, and highly selective catalysts to boost the chemisorption, activation, and coupling of inert N2 and...

A water recycling system with improved efficiencies to satisfy the water demand in a closed-loop environment is required in the Environmental Control and Life Support Systems (ECLSS) for the National Aeronautics and Space Administration (NASA). The wastewater recycling system in the ECLSS has a water reclamation efficiency limitation of 90%. Theref...

An autonomous electrochemical system prototype for ammonia oxidation reaction (AOR) measurements was efficiently done inside a 4" x 4" x 8" 2U Nanoracks module at the International Space Station (ISS). This system, the Ammonia Electrooxidation Lab at the ISS (AELISS), included an autonomous electrochemical system that complied with NASA ISS nondisc...

Telomerase overexpression has been associated directly with cancer, and the enzyme itself is recognized within the scientific community as a cancer biomarker. BIDEA's biosensing strip (BBS) is an innovative technology capable of detecting the presence of telomerase activity (TA) using electrochemical impedance spectroscopy (EIS). This BBS is an int...

The size and morphology of nanomaterials replicate optical, electrical, and mechanical properties and their applications. In this paper, for the first time, ZnO hierarchical nanostructures were grown on Zn foil through electrochemical anodization in the presence of fluoride ions at room temperature in water/glycerol electrolyte. Fluoride ions are v...

Nanoscale zero-valent iron (nZVI) particles are currently used for environmental remediation due to their ion sequester ability. This trait plus their magnetic behavior, and biocompatibility, makes them a promising alternative for heavy metal poisoning treatment, development of MRI dye, and drug delivery loads, among others. Their rapid passivation...

Ongoing efforts to develop single-atom catalysts (SACs) for the oxygen reduction reaction (ORR) typically focus on SACs with cationic metal centers, while SACs with anionic metal centers (anionic SACs) have been generally neglected. However, anionic SACs may offer excellent active sites for ORR, since anionic metal centers could facilitate the acti...

The water recovery system (WRS) within the Environmental Control and Life Support System (ECLSS) for the International Space Station (ISS) recovers and recycles up to 90% water from human waste. However, the WRS has lifetime/durability limitations requiring the supply of hazardous chemicals and filter units to treat the system components to maintai...

A wastewater recycling system with enhanced efficiencies is needed to satisfy the water need in a closed-loop environment required by NASA's Environmental Control and Life Support Systems (ECLSS). Wastewater treatment and water-recovery system within the ECLSS has an efficiency limitation of approximately 90% of water reclamation. To provide self-s...

Studying the oxygen reduction reaction (ORR) in the alkaline electrolyte has proven to promote better catalytic responses and accessibility to commercialization. Ni-nanowires (NWs) were synthesized via the solvothermal method and modified with Pt using the spontaneous galvanic displacement method to obtain PtNi-NWs. Carbon Vulcan XC-72R (V) was use...

Highly dispersed iron-based quantum dots onto powdered Vulcan XC-72R substrate were successfully electrodeposited by the rotating disk slurry (RoDSE) technique. Our findings through chemical physics characterization revealed that the continuous electron pathway interaction between the interface metal-carbon is controlled. The RDE, RRDE, and PGU of...

A fast PCR-assisted impedimetric biosensor was developed for the selective detection of the clbN gene from the polyketide synthase (pks) genomic island in real Escherichia coli samples. This genomic island is responsible for the production of colibactin, a harmful genotoxin that has been associated with colorectal cancer. The experimental protocol...

Carbon-supported Ag nanocatalysts, synthesized at five different electrodeposition potentials ranging from 0.0 to 0.4 V vs. RHE, were successfully prepared by using the rotating disk slurry electrode (RoDSE) technique. This was done to determine the ideal electrodeposition parameters that facilitate optimal metal loading and particle dispersion for...

The glucose oxidation reaction, at Pd on unsupported carbon nano-onions (Pd/CNOs), has been studied by using physical and electrochemical characterization techniques. The rotating disk slurry electrode (RoDSE) technique was used for the Pd electrodeposition at the carbon support. The Pd/CNO catalyst was compared with the optimized RoDSE-prepared Pd...

Onion-like carbon nanoparticles were synthesized from diamond nanoparticles to be used as the precursor for graphene oxide quantum dots. Onion-like carbon nanoparticles were exfoliated to produce two types of nanoparticles, graphene oxide quantum dots that showed size-dependent fluorescence and highly stable inner cores. Multicolor fluorescent quan...

Fuel cells (FC) are emerging technologies that will eventually sustain energy demands replacing fossil fuels. However, the Oxygen reduction reaction (ORR) behaves sluggishly in acidic medium, where actual commercialization of FC concentrates. An alternative is to use alkaline environment were the ORR have demonstrated great activity using less expe...

Plants may be used to remove or convert pollutants into harmless products by bioaccumulating, degrading, extracting, or immobilizing them. Phytoremediation processes offer advantages over traditional remediation methods such as chemical oxidation, excavation, and thermal treatments. A combined usage of mangroves and nano zero valent iron (nZVI), co...

Fuel cells (FC) are emerging technologies that will eventually sustain energy demands replacing fossil fuels. However, the Oxygen reduction reaction (ORR) behaves sluggishly in acidic medium, were actual commercialization of FC concentrates. An alternative is to use alkaline environment were the ORR have demonstrated great activity using non-precio...

Colibactin is a natural product made by numerous strains of E. coli that harbor the pks genomic island. The deletion of one of the genes within the pks island, the peptidase clbP, has been found to disrupt the maturation of colibactin, thus promoting the accumulation in the periplasmic space of numerous biosynthesis intermediates, some of which hav...

Precise tuning of the electronic properties of Ag/C using under potentially deposited (UPD) Cu and subsequent galvanic displacement to deposit atomically dispersed loading of Pd resulted in a robust bimetallic alloy with significant activity for the oxygen reduction reaction (ORR: O2 + 4e-→ H2O) in alkaline media. The specific design of the catalys...

In the last decade, researchers have been searching for innovative platforms, methods, and techniques able to address recurring problems with the current cancer detection methods. Early disease detection, fast results, point-of-care sensing, and cost are among the most prevalent issues that need further exploration in this field. Herein, studies ar...

In order to facilitate extended human space travel, solutions and innovations are required to enable habitation in microgravity spacecraft habitats such as International space station (ISS), with limited earth availability. The existing supply of water on the International Space Station (ISS) is managed by Environmental Control and Life Support Sys...

Proton exchange membrane fuel cells (PEMFC) are a promising power technology for vehicles. However, their commercialization has been hindered due to the cathodic process of the oxygen reduction reaction (ORR). The ORR usually uses high-cost platinum-based electrocatalysts, which is also a major drawback towards commercialization. High overpotential...

Novel technologies with limited earth support are required to enable habitation in microgravity spacecraft habitats such as International space station (ISS). One area of particular need for the interstellar travel community is cleaning/sanitizing supplies to meet personal hygiene requirements, which is currently accomplished through the use of pre...

The recycling of human urine has become a main research area in wastewater treatment due to the increased demand for water. Urine is composed of 95% water, 2% urea and other organic and inorganic compounds. Urea is a toxic molecule that may cause renal failure and gastrointestinal bleeding. Nevertheless, it is difficult to remove by common methods...

Human space travel requires several technological developments that support fuel generation and the energy-efficient preservation of closed systems in microgravity spaceship environments [1]. Fuel cells are promising candidates for clean energy conversion for terrestrial and space applications. The overpotential required for the Oxygen Reduction Re...

An electrochemical whole cell Lab-on-a-Chip sensor for the detection of urea in synthetic urine has been developed. Urea was indirectly monitored by the electrochemical ammonia oxidation liberated by the microbial P. vulgaris microorganism surface membrane reaction. For this, a custom-made platinum miniature electrode platform utilizing lift-off ph...

Technological innovations are essential to enable energy-efficient maintenance of closed air, water, and waste systems for interplanetary travel with limited resupply options and microgravity living conditions. One particular need for the interstellar travel community is disinfection to meet personal hygiene requirements. At present, surface disinf...

One of the most challenging problems when trying to recycle urine for different purposes is the removal of urea. In this project we studied an ureolysis system using the bacterium Proteus vulgaris for the transformation of urea to ammonia and its subsequent oxidation to nitrogen at a Pt electrode. Our system was tested under different conditions, e...

Current urine recycling treatments are unable to completely recover clean water free of toxic metabolic products such as urea. Urea is a small and uncharged molecule, diffulting its removal from wastewater. Previous publications from our research group reported the use of immobilized urease enzyme on carbon matrix as a urea bioreactor to convert ur...

Carbon-supported Ag-Pd bimetallic nanocatalysts were successfully synthesized via the rotating disk slurry electrode (RoDSE) technique in a nominal precursor solution as a cost-effective means to improve oxygen reduction reaction (ORR) performance in fuel cell (FC) applications. Silver and palladium have both individually shown good catalytic activ...

A series of sherds from the archeological site of Qotakalli in the area of Cusco (Perú), corresponding to four different Inka periods, were studied by means of square wave voltammetry of immobilized particles (VIMP) and electrochemical impedance spectroscopy (EIS). Ceramic microparticles were placed on a graphite working electrode and were characte...

Graphene possesses excellent mechanical strength and chemical inertness with high intrinsic carrier mobility and superior flexibility making them exceptional candidates for optoelectronic applications. Graphene quantum dots (GQDs) derived from graphene domains have been widely explored to study their photoluminescence properties which can be tuned...

Platinum was electrodeposited onto CeO2/Vulcan XC-72R to produce Pt/CeO2-x/Vulcan XC-72R catalysts using a Rotating Disk Slurry Electrode Technique. The activity of the catalysts was measured towards methanol and ethanol electro-oxidation in alkaline media by cyclic voltammetry. The materials were examined using electron microscopy. The results wer...

An electrosynthesis method to obtain Au nanoparticles dispersed on carbon Vulcan XC-72R support material was done using AuX4- (X = Cl-, Br-, and OH-) as molecular precursors and different electrolyte media. The Au surface structure was significantly enhanced using KOH as an electrolyte as opposed to KBr and H2SO4. Cyclic voltammetry was used as a s...

The development of low‐cost and efficient electrocatalysts for nitrogen reduction reaction (NRR) at ambient conditions is crucial for NH3 synthesis and provides an alternative to the traditional Harber‐Bosch process. Herein, by means of density functional theory (DFT) computations, the catalytic performance of a series of single metal atoms support...

A unique core-shell structured catalyst, composed of Pt nanorod shells and Ag nanowires cores, is synthesized. The as-prepared Pt nanorods are ca. 2–4 nm in diameter and ca. 26–46 nm in length. The as-prepared catalyst shows outstanding activity and stability for methanol oxidation reaction compared to commercial Pt black catalyst.

In order to facilitate extended human space travel, solutions and innovations are required to enable efficient long life operation of life support systems with limited earth availability. The existing supply of air and water on the International Space Station (ISS) is managed by Environmental Control and Life Support System (ECLSS) which recovers a...

The Rotating Disk Slurry Electrodeposition (RoDSE) technique is a novel method which can electrochemically deposit metal nanoparticles on a given conductive support and produce a powder catalyst for diverse applications, e.g. ethanol oxidation reaction (EOR). This technique was used to electrodeposit Pd nanoparticles on carbon Vulcan XC–72R nanofla...

In the last decade, researchers are looking for platforms, methods, and techniques that mitigate all the problems that current cancer detection methods have; expensiveness, can not be use in a point of care location, do not detects early steps of the disease and are time consuming tests. Nowadays, various researchers have focused on the development...

Novel technologies with limited earth support are required to enable energy-efficient maintenance of closed air, water, and waste systems in microgravity spacecraft habitats such as International space station (ISS). One area of need for the interstellar travel community is cleaning/sanitizing supplies to meet personal hygiene requirements, which i...

Novel technologies with limited earth support are required to enable energy-efficient maintenance of closed air, water, and waste systems in microgravity spacecraft habitats such as International space station (ISS). One area of need for the interstellar travel community is cleaning/sanitizing supplies to meet personal hygiene requirements, which i...

In order to facilitate human space travel, solutions and innovations are required for supporting the efficient maintenance of water, closed air, and waste systems in spacecraft habitats that operate on planetary environments. As missions are foreseen to be extended with limited earth resupply available there is need to develop durable and sustainab...

One of the most challenging problems when trying to recycle urine for different purposes is the removal of urea. In this project we studied an ureolysis system using the bacterium Proteus vulgaris for the transformation of urea to ammonia and its subsequent oxidation to nitrogen at a Pt working electrode. Our system was tested under different pH, m...

Electrochemical reduction of nitric oxide (NOER) is a promising technology for the removal of harmful N-containing species in groundwater under mild conditions. In this work, by means of density functional theory computations, we systematically investigated the potential of utilizing the experimentally feasible transition metal-N4/graphenes as the...

Rotating Disk Slurry Electrodeposition of Platinum at Y-Zeolite/Carbon Vulcan XC-72R for Methanol Oxidation in Alkaline Media.

Platinum was electrodeposited onto CeO2/Vulcan XC-72R to produce Pt/CeO2-x/Vulcan XC-72R catalysts using a Rotating Disk Slurry Electrode Technique. The activity of the catalysts was measured towards methanol and ethanol electro-oxidation in alkaline media by cyclic voltammetry. The materials were examined using electron microscopy. The results wer...

The recombinant HbI was fused with a poly-Lys tag ((Lys)6-tagged rHbI) for specific-site covalent immobilization on two carbon nanotube transducer surfaces, i.e., powder and vertically aligned carbon nanotubes. The immobilization was achieved by following two steps: (1) generation of amine-reactive ester from the carboxylic acid groups of the surfa...

The effect of microgravity on the electrochemical oxidation of ammonia at platinum nanoparticles supported on modified mesoporous carbons (MPC) with three different pore diameters (64, 100, and 137 Å) was studied via the chronoamperometric technique in a half-cell. The catalysts were prepared by a H2 reductive process of PtCl\(_{6}^{\mathrm {4-}}\)...

Energy storage and conversion mechanism are different for on lithium ion batteries (LIB) and supercapacitors (Electrical Double Layer Capacitors- EDLCs), materials that can be used for both could lead in the future the energy storage and conversion technologies. We explored a non-conventional process to synthesize SnO 2 /G/GO composite powder which...

This is a study of the chronoamperometric performance of the electrochemical oxidation of ammonia in an alkaline fuel cell for space applications. Under microgravity the performance of a fuel cell is diminished by the absence of buoyancy since nitrogen gas is produced. The following catalysts were studied: platinum nanocubes of ca. 10nm, platinum n...

Prostate cancer is the most frequently diagnosed cancer and the second cause of cancer-related deaths in American men. Bioavailability of therapeutic agents is important for the treatment effectiveness. Previous studies have shown that the development of nanoparticles (NPs) drug delivery vehicles offers an opportunity for targeted drug delivery to...

Hybrid Pt/TiO2-C catalysts were synthesized via photodeposition in this study in order to increase the kinetics and the carbonate yield of the Ethanol Oxidation Reaction. Photodeposition was chosen because it was believed that the Pt nanoparticles would deposit predominately on top of the oxide sites, which would change the reactivity of the Pt nan...

In this work, we study the mechanism and kinetics of the oxygen reduction reaction (ORR) over Pd/C, Pd2Co/C and PdCo2/C electrocatalysts synthesized by thermal reduction of organometallic precursors, such as [Pd3(μ-3-Ph-pz)6], [Et4N]2[Pd2Co(μ-4-I-3,5-Me2-pz)4Cl4], and [Et4N]2[PdCo2(μ-4-I-3,5-Me2-pz)4Cl4]. The methanol tolerance and formation of per...

Among the numerous technological advances sought in order to facilitate human space travel, solutions are needed for technology that supports energy-efficient maintenance of closed air, water, and waste systems in microgravity spacecraft habitats, like Mars. In particular, a technique for the in-situ generation of cleaning/sanitizing solutions is n...

This is a study of the chronoamperometric performance of the electrochemical oxidation of ammonia in an alkaline fuel cell for space applications. Under microgravity the performance of a fuel cell is diminished by the absence of buoyancy since nitrogen gas is produced. The following catalysts were studied: platinum nanocubes of ca. 10nm, platinum n...

Among the numerous technological advances sought in order to facilitate human space travel, solutions are needed for technology that supports energy-efficient maintenance of closed air, water, and waste systems in microgravity spacecraft habitats, like Mars. In particular, a technique for the in-situ generation of cleaning/sanitizing solutions is n...

Developing novel strategies to effectively detect biomarkers is of utmost importance in the early detection of cancer cells to increase the chances of a successful therapy. The proposed biosensor microchips works by tethering a biomolecular probe on the interdigital gold electrode array surfaces. This biomolecule probe can be customized according t...

Molybdenum disulfide (MoS2) is a layered material with promising photo-electroactive properties with possible application in solar cell devices. In this work, exfoliated MoS2 (E-MoS2) was produced using a chemical intercalation and exfoliation process. After an exhaustive characterization of the material, two different solar cell arrays were studie...

A robust electrodeposition method consisting of the rotating disk slurry electrode (RoDSE) technique to obtain Au nanoparticles highly dispersed on a conductive carbonaceous support, i.e., Vulcan XC-72R, for ethanol electrooxidation reaction in alkaline media was developed. Ceria was used as a cocatalyst using a Ce(III)-EDTA impregnation method in...

The Rotating Disk Slurry Electrodeposition (RoDSE) technique is a novel method allowing to deposit electrochemically metal nanoparticles on a given conductive support and produce a powder catalyst for diverse applications, for example, ethanol oxidation reaction (EOR). This technique was used to electrodeposit Pd nanoparticles on carbon Vulcan XC-7...

The ammonia oxidation reaction has been a topic of interest due to its possible use as a fuel in alkaline fuel cell systems. This may play a role on wastewater treatment for a stand-alone purification device. Nevertheless, the oxidation of ammonia is a complex surface process that needs catalyst development and synthesis. The Pt (100) facet has sho...

By means of density functional theory (DFT) computations, we investigated the potential of oxygenterminated Cr2C (Cr2CO2) as a cathode material for lithium and non-lithium ion batteries (LIBs and NLIBs). Our computations revealed that the Cr2CO2 exhibits the extraordinary characteristics that the LIB and NLIB electrodes require, including good elec...