http://hdl.handle.net/10563/1000003 Wed, 12 Aug 2026 20:59:54 GMT 2026-08-12T20:59:54Z http://hdl.handle.net/10563/1012855 Triboelectrically-induced non-contact polypropylene/polyvinylidene fluoride sensor with low permittivity supporting layers affecting its interfacial charge dynamics Slobodian, Petr; Riha, Pavel; Hausnerova, Berenika; Olejnik, Robert; Matyas, Jiri This work presents a simple and low-cost approach to triboelectric sensing based on commercially available nonwoven polypropylene (PP) membranes paired with electrospun polyvinylidene fluoride (PVDF) to form a triboelectric nanogenerator (TENG), which is further utilized as a sensor operating predominantly in a non-contact regime. The initial contact electrification creates an interfacial charge state that is retained after contact, allowing subsequent separation changes to generate electrical signals via electrostatic induction without requiring continuous contact. The introduction low-permittivity sublayers (polyvinyl chloride (PVC), biaxially oriented polyethylene terephthalate (BOPET), and low-density polyethylene (LDPE)) beneath the tribonegative PVDF membrane significantly enhances the TENG’s mechano-electric performance by modifying the electric field distribution in the multilayer dielectric structure. The PP/PVDF+LDPE layer achieves a peak open-circuit voltage of 689 V and a maximum power density of 5.46 mWcm⁻² in comparison to 376 V and 2.05 mWcm⁻², respectively, for PP/PVDF. This confirms that the dielectric permittivity of the supporting layer is a key parameter controlling the electrical output of the PP/PVDF triboelectric system. The device was validated under various pressure stimuli and vibrations demonstrating its ability to simultaneously sense motion and harvest energy. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/10563/1012855 2026-01-01T00:00:00Z http://hdl.handle.net/10563/1012848 Asymmetric supercapacitor based on biomass-derived carbon electrodes functionalized with NdFeB Delawary, Ahmad Reshad; Bubulinca, Constantin; Kazantseva, Natalia E.; Sáha, Petr; Le, Quoc Bao; Gupta, Ram K.; Kiefer, Rudolf Supercapacitors (SCs) are highly attractive energy storage devices, and modern research is focused on using waste materials to reduce environmental impact. This study processed biowaste from local brewery production to produce a highly specific mesoporous activated carbon (AC) for SC electrode scaffolds. Polyaniline (PANI) was synthesized and incorporated into the AC scaffold, thereby enhancing performance. The AC and PANI combination (ACP) achieved a specific capacitance of 173.7 F/g at 1 A/g, with 92% retention after 5000 cycles. Using NdFeB (ACN) particles, the anode showed a specific capacitance of 127 F/g and over 99% retention. An asymmetrical ACN//ACP cell demonstrated promising performance with 70% efficiency. This study highlights the potential of using biowaste for high-performance SC electrodes and the effective synergy between AC and PANI. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/10563/1012848 2026-01-01T00:00:00Z http://hdl.handle.net/10563/1012852 Microwave-assisted one-pot sol–gel synthesis of tungsten silicate microspheres with dispersed WOx and their activity in ethanol dehydration Škoda, David; Pokorný, Tomáš; Hanulíková, Barbora; Stýskalík, Aleš; Hlavenková, Zuzana; Šimoníková, Lucie; Varaďa, Jan; Leonová, Lucie; Kuřitka, Ivo; Poleunis, Claude; Debecker, Damien P. This study introduces a novel microspherical W–SiO2 heterogeneous catalyst for alcohol dehydration, prepared via an innovative microwave-assisted condensation synthesis method. The process involves the microwave-assisted preparation of a hybrid tungsten naphthalene dicarboxylate-based precursor solution, which is subsequently condensed with (3-aminopropyl)triethoxysilane in a single step—eliminating the need for separate silica support preparation, as required in conventional impregnation methods. After calcination at 550 °C, the resulting amorphous and porous microspheres contain highly dispersed tungsten species (with loadings of 2, 6, and 12 wt%), with no crystalline WO3 phase detected, even at the highest loading. Compared to a 12 wt% WO3/SiO2 catalyst prepared via conventional impregnation, the W–SiO2 microspheres exhibit higher catalytic activity and ethylene selectivity in ethanol dehydration at 420 °C. Notably, the 2W–SiO2 catalyst achieved the highest initial ethylene productivity per mole of tungsten (520 mmol mmolW−1 h−1), maintaining 230 mmol mmolW−1 h−1 after 1000 minutes on stream, indicating high long-term stability. In terms of mass-specific performance, the 12W–SiO2 catalyst reached 133 mmol g−1 h−1, outperforming other comparable previously reported tungsten–silica catalysts. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/10563/1012852 2026-01-01T00:00:00Z http://hdl.handle.net/10563/1012851 Evaluating environmental and economic perspectives of hybrid energy storage systems: A review Paračková, Mária; Pechancová, Viera; Sáha, Petr; Oriňáková, Renáta The escalating global challenges have driven significant shifts toward cleaner energy solutions, many of which rely on energy storage technologies. However, there is currently no single energy storage technology that meets all of the application requirements. To address this, hybrid energy storage systems, which combine two or more types of storage devices, have emerged as a promising solution. To support the sustainable implementation of hybrid energy storage systems, this work provides a comprehensive overview of metrics and factors that influence their financial and environmental impacts. In addition, the article discusses the challenges, recommendations, and future directions in conducting sustainability analyses. Thu, 01 Jan 2026 00:00:00 GMT http://hdl.handle.net/10563/1012851 2026-01-01T00:00:00Z