The use of hydrogen as fuel presents many safety challenges due to its flammability and explosive nature, combined with its lack of color, taste, and odor. The purpose of this paper is to present an electrochemical sensor that can achieve rapid and accurate detection of hydrogen leakage. This paper presents both the component elements of the sensor, like sensing material, sensing element, and signal conditioning, as well as the electronic protection and signaling module of the critical concentrations of H₂. The sensing material consists of a catalyst type Vulcan XC72 40% Pt, from FuelCellStore, (Bryan, TX, USA). The sensing element is based on a membrane electrode assembly (MEA) system that includes a cathode electrode, an ion-conducting membrane type Nafion 117, from FuelCellStore, (Bryan, TX, USA). and an anode electrode mounted in a coin cell type CR2016, from Xiamen Tob New Energy Technology Co., Ltd, (Xiamen City, Fujian Province, China). The electronic block for electrical signal conditioning, which is delivered by the sensing element, uses an INA111, from Burr-Brown by Texas Instruments Corporation, (Dallas, TX, USA). instrumentation operational amplifier. The main characteristics of the electrochemical sensor for hydrogen leakage detection are operation at room temperature so it does not require a heater, maximum amperometric response time of 1 s, fast recovery time of maximum 1 s, and extended range of hydrogen concentrations detection in a range of up to 20%.

Ultra-high-molecular-weight polyethylene (UHMWPE) matrices containing low-density polyethylene (LDPE), hydroxyapatite (HAp) as filler, and rosemary extract (RM) as stabilizer were investigated for their qualification for long-term applications. The significant contributions of the blend components were analyzed, and variations in mechanical properties, oxidation strength, thermal behavior, crystallinity, and wettability were discussed. SEM images of microstructural peculiarities completed the introspective survey. The stability improvement due to the presence of both additives was an increase in the total degradation period of 67% in comparison with an unmodified HDPE/UHMWPE blend when the materials were subjected to a 50 kGy γ-dose. There was growth in activation energies from 121 kJ mol⁻¹ to 139 kJ mol⁻¹ when HAp and rosemary extract delayed oxidation. The exposure of samples to the action of γ-rays was found to be a proper procedure for accomplishing accelerated oxidative degradation. The presence of rosemary extract and HAp powder significantly increased the thermal and oxidation resistances. The calculation of material lifetimes at various temperatures provided meaningful information on the wearability and integrity of the inspected composites.

The relative performance of different porous solids in different applications is highly dependent on the internal pore structure of each material. Highly porous carbon materials can be prepared by evaporative drying and the pyrolysis of resorcinol-formaldehyde gels. By determining the correct synthesis parameters, the pore system of such materials can be reshaped. Depending on some important processing factors such as the dilution ratio or the initial pH of the precursor solution, various porous or non-porous carbon materials can be synthesized. This paper addresses carbon xerogels (CX) designed as a material electrode in capacitive deionization (CDI) systems for water desalination. In this work CX materials were synthesized via poly-condensation reactions of resorcinol with formaldehyde (RF) on a carbon felt sheet followed by pyrolysis. The resulting sheets were used as electrodes to develop a CDI experimental multi-cell laboratory system. The initial pH of the RF solution and the dilution ratio effect on the resulting carbon surface area and structure were analyzed. Surface area measurements using the BET method and an electrochemical capacitance evaluation of the obtained xerogels through electrochemical impedance spectroscopy were also performed. Finally, using our experimental CDI multi-cell laboratory system based on the obtained CX, we discuss the experimental data for the desalination rate as a function of the voltage and salt concentration. As a result, the developed model’s efficiency is demonstrated. The main goal of this work was to develop an efficient electrode-based novel carbon that could be commercially competitive, as well as to create guidelines for future desalination research using CX electrode materials.

Experimental assessment of the hydrogen (H₂)-adsorption capacities of metal-doped carbon nanostructured materials were investigated in this study. Given their intrinsic characteristics, nanostructured carbonic materials show great potential for different applications that require H₂, one such being their use as hydrogen carriers in the automotive sector. The current paper considers two types of carbonic substrates (carbon nanotubes and polyaniline) functionalized and doped with platinic metals: Pt, Ru and Ir. The H₂-adsorption capacities of the materials were assessed at 293 K and at relatively low pressures (10, 20 and 30 bar). Thus, nanostructured polyaniline (p-C₆H₅NH₂) and multi-walled carbon nanotubes (MW-CNTs) were subject to noble-metal doping in order to assess their physical H₂-adsorption capacities. The two types of substrates have different structures and characteristics, one being a “synthetic metal” and the other an amorphous carbon substrate. The metals used for doping were Platinum (Pt), Iridium (Ir) and Ruthenium (Ru), and the doping procedure consisted of chemical reaction between the metals’ salts and the carbonic substrate after the latter’s physical activation. Physical H₂-adsorption capacity was determined with equipment designed to measure porous materials’ adsorption capacities at pressures ranging from 1 to 200 bar. The obtained results showed an increase inH₂-adsorption capacity of 293% from 10 to 30 bar for Ru, 270% for Ir and 256% for Pt doping in the case of the MW-CNTs, and 296% for Ru, 282% for Ir and 251% for Pt from 10 to 30 bar in the case of p-C₆H₅NH₂. As the main conclusion, even though Pt is known to be the main metal used in reactions involving H₂, Ru and Ir showed better potential for this application, namely, as hydrogen-carrier materials for use in the automotive sector.