Electrocatalytically active nanocomposites play a vital role in energy generation, conversion, and storage technologies. Transition metal-based catalysts such as nickel and iron and their pnictide (phosphide), and chalcogenide (selenide) compounds exhibit good activity for hydrogen evolution reaction (HER) in the alkaline environment. In this study, transition metals-based catalysts (Ni-P-Se, Fe-P-Se, and Ni-Fe-P-Se) solutions were prepared using a simple one-pot method. Prepared solutions were deposited on Ni foam, and different characterization techniques were used to determine the composition, structure, and morphology of as-prepared catalysts. Furthermore, it was found that Ni-Fe-P-Se as a cathode material showed better HER performance compared to other investigated materials with the overpotential value of 316 mV at 10 mA cm-2 current density and 89 mV dec-1 Tafel slope value. The stability tests of the as-prepared catalyst confirmed that the synergistic effect between various elements enhances the electrocatalytic performance for up to 24 hours, providing a fair, stable nature of Ni-Fe-P-Se based sample.

The reliance on fossil fuels has led to numerous environmental challenges, highlighting the urgent need for alternative energy sources that minimize contamination and promote eco-friendliness. In this context, hydrogen (H2) emerges as a promising fuel due to its zero-carbon emissions. Within various methods for H2 production, electrochemical water splitting (EWS) stands out as a viable approach. Traditionally, noble metals, such as platinum and iridium, have been employed as electrocatalysts to efficiently facilitate the hydrogen evolution reaction (HER) in desired electrolytes (such as alkaline). Recently, research has focused on the use of Prussian blue (PB) as an innovative electrocatalyst material for EWS. Herein, we developed PB-based electrocatalysts for HER in an alkaline medium. The electrocatalyst comprising PB combined with phosphorus exhibited impressive electrochemical properties, achieving a minimal overpotential of 103 mV at a current density of 10 mA/cm2 and maintaining durability over 20 h, along with extended electrochemical performance. This material composition has considerable promise as a potential option for energy conversion systems, which can aid future sustainability initiatives.

This study presents an approach for predicting temperatures and ignition time during the cook-off process of solid propellants, with a focus on identifying potential hot spots and conduction losses. A pool fire temperature model is introduced to enhance the understanding of the thermal stability of solid propellants, specifically ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB). Numerical simulations were performed to analyze the thermal behavior of the AP/HTPB propellant under cook-off conditions using a three-dimensional, transient model with heating rates between 0.67 and 0.8 K/s. The ignition temperatures for the AP/HTPB propellant varied with distance and time, recorded at 641.40 K, 598.10 K, and 554.43 K. To streamline the computations, a simplified model with hot wall conditions for the outer steel wall of the propellant was adopted, accurately replicating the cook-off processes under specific experimental conditions and aligning closely with experimental findings. The similarity between the model predictions and experimental data provides a reliable means of assessing the explosion risk of AP/HTPB in cook-off scenarios, with relative errors of 0.845% and 2.03% for ignition temperature and ignition delay time, respectively. Additionally, the data generated from this model can aid in developing safety protocols for plant design, establishing safety zones, and planning emergency evacuation routes to mitigate potential hazards.