Energie budoucnosti a inovace

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Heterolayered carbon allotrope architectonics via multi-material 3D printing for advanced electrochemical devices
(TAYLOR & FRANCIS LTD, 2023-12-31) Palacios Corella, Mario; Sanna, Michela; Muoz Martin, Jose Maria; Ghosh, Kalyan; Wert, Stefan; Pumera, Martin
3D printing has become a powerful technique in electrochemistry for fabricating electrodes, thanks to readily available conductive nanocomposite filaments, such as those based on carbon fillers (i.e., carbon nanotubes (CNTs) or carbon black (CB)) within an insulating polymeric matrix like polylactic acid (PLA). Inspired by inorganic heterostructures that enhance the functional characteristics of nanomaterials, we fabricated hetero-layered 3D printed devices based on carbon allotropes using a layer-by-layer assembly approach. The heterolayers were customised through the alternate integration of different carbon allotrope filaments via a multi-material 3D printing technique, allowing for a time-effective method to enhance electrochemical performance. As a first demonstration of applicability, CNT/PLA and CB/PLA filaments were utilised to construct ordered hetero-layered carbon-based electrodes. This contrasts with conventional methods where various carbon species are mixed in the same composite-based filament used for building electrochemical devices. Multi-material 3D-printed carbon electrodes exhibit improved electrochemical performance in energy conversion (e.g., hydrogen evolution reaction or HER) and sensing applications (e.g., ascorbic acid detection) compared to single-material electrodes. This work paves the way for manufacturing advanced 3D-printed heterolayered electrodes with enhanced electrochemical activity through multi-material 3D printing technology.
Quantum Material-Based Self-Propelled Microrobots for the Optical "On-the-Fly" Monitoring of DNA
(AMER CHEMICAL SOC, 2023-12-11) Jyoti, Jyoti; Muoz Martin, Jose Maria; Pumera, Martin
Quantum dot-based materials have been found to be excellent platforms for biosensing and bioimaging applications. Herein, self-propelled microrobots made of graphene quantum dots (GQD-MRs) have been synthesized and explored as unconventional dynamic biocarriers toward the optical "on-the-fly" monitoring of DNA. As a first demonstration of applicability, GQD-MRs have been first biofunctionalized with a DNA biomarker (i.e., fluorescein amidite-labeled, FAM-L) via hydrophobic pi-stacking interactions and subsequently exposed toward different concentrations of a DNA target. The biomarker-target hybridization process leads to a biomarker release from the GQD-MR surface, resulting in a linear alteration in the fluorescence intensity of the dynamic biocarrier at the nM range (1-100 nM, R-2 = 0.99), also demonstrating excellent selectivity and sensitivity, with a detection limit as low as 0.05 nM. Consequently, the developed dynamic biocarriers, which combine the appealing features of GQDs (e.g., water solubility, fluorescent activity, and supramolecular pi-stacking interactions) with the autonomous mobility of MRs, present themselves as potential autonomous micromachines to be exploited as highly efficient and sensitive "on-the-fly" biosensing systems. This method is general and can be simply customized by tailoring the biomarker anchored to the GQD-MR's surface.
Multi-Sensing Platform Based on 2D Monoelement Germanane
(WILEY-V C H VERLAG GMBH, 2023-11-01) Vaghasiya, Jayraj Vinubhai; Mayorga-Martinez, Carmen C.; Sonigara, Kevalkumar Kishorbhai; Lazar, Petr; Pumera, Martin
Covalently functionalized germanane is a novel type of fluorescent probe that can be employed in material science and analytical sensing. Here, a fluorometric sensing platform based on methyl-functionalized germanane (CH3Ge) is developed for gas (humidity and ammonia) sensing, pH (1-9) sensing, and anti-counterfeiting. Luminescence (red-orange) is seen when a gas molecule intercalates into the interlayer space of CH3Ge and the luminescence disappears upon deintercalation. This allows for direct detection of gas absorption via fluorometric measurements of the CH3Ge. Structural and optical properties of CH3Ge with intercalated gas molecules are investigated by density functional theory (DFT). To demonstrate real-time and on-the-spot testing, absorbed gas molecules are first precisely quantified by CH3Ge using a smartphone camera with an installed color intensity processing application (APP). Further, CH3Ge-paper-based sensor is integrated into real food packets (e.g., fish and milk) to monitor the shelf life of perishable foods. Finally, CH3Ge-based rewritable paper is applied in water jet printing to illustrate the potential for secret communication with quick coloration and good reversibility by water evaporation.
Laser-Induced MXene-Functionalized Graphene Nanoarchitectonics-Based Microsupercapacitor for Health Monitoring Application
(AMER CHEMICAL SOC, 2023-10-04) Deshmukh, Sujit; Ghosh, Kalyan; Pykal, Martin; Otyepka, Michal; Pumera, Martin
Microsupercapacitors (micro-SCs) with mechanical flexibility have the potential to complement or even replace microbatteries in the portable electronics sector, particularly for portable biomonitoring devices. The real-time biomonitoring of the human body's physical status using lightweight, flexible, and wearable micro-SCs is important to consider, but the main limitation is, however, the low energy density of micro-SCs as compared to microbatteries. Here using a temporally and spatially controlled picosecond pulsed laser, we developed high-energy-density micro-SCs integrated with a force sensing device to monitor a human body's radial artery pulses. The photochemically synthesized spherical laser-induced MXene (Ti3C2T x )-derived oxide nanoparticles uniformly attached to laser-induced graphene (LIG) act as active electrode materials for micro-SCs. The molecular dynamics simulations and detailed spectroscopic analysis reveal the synergistic interfacial interaction mechanism of Ti-O-C covalent bonding between MXene and LIG. The incorporation of MXene nanosheets improves the graphene sheet alignment and ion transport while minimizing self-restacking. Furthermore, the micro-SCs based on a nano-MXene-LIG hybrid demonstrate high mechanical flexibility, durability, ultrahigh energy density (21.16 x 10(-3) mWh cm(-2)), and excellent capacitance (similar to 100 mF cm(-2) @ 10 mV s(-1)) with long cycle life (91% retention after 10 000 cycles). Such a single-step roll-to-roll highly reproducible manufacturing technique using a picosecond pulsed laser to induce MXene-derived spherical oxide nanoparticles (size of quantum dots) attached uniformly to laser-induced graphene for biomedical device fabrication is expected to find a wide range of applications.
Fe-MOF Catalytic Nanoarchitectonic toward Electrochemical Ammonia Production
(American Chemical Society, 2023-10-02) Kandambath Padinjareveetil, Akshay Kumar; Perales Rondon, Juan Victor; Zaoralová, Dagmar; Otyepka, Michal; Alduhaish, Osamah; Pumera, Martin
Electrochemical reduction of nitrate into ammonia has lately been identified as one among the promising solutions to address the challenges triggered by the growing global energy demand. Exploring newer electrocatalyst materials is vital to make this process effective and feasible. Recently, metal-organic framework (MOF)-based catalysts are being well investigated for electrocatalytic ammonia synthesis, accounting for their enhanced structural and compositional integrity during catalytic reduction reactions. In this study, we investigate the ability of the PCN-250-Fe-3 MOF toward ammonia production in its pristine and activated forms. The activated MOF catalyst delivered a faradaic efficiency of about 90% at -1 V vs RHE and a yield rate of 2.5 x 10(-4) mol cm(-2) h(-1), while the pristine catalyst delivered a 60% faradaic efficiency at the same potential. Theoretical studies further provide insights into the nitrate reduction reaction mechanism catalyzed by the PCN-250-Fe-3 MOF catalyst. In short, simpler and cost-effective strategies such as pretreatment of electrocatalysts have an upper hand in aggravating the intrinsic material properties, for catalytic applications, when compared to conventional material modification approaches.

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