Synergistic Enhancement of MgH₂ Hydrolysis via Microalloying and Precursor-Tailored g-C<sub>3</sub>N<sub>4</sub>

MgH₂ is recognized as an excellent material for hydrogen production due to its high theoretical hydrogen production capacity, environmental friendliness, safety and ease of transport. However, during the hydrogen production process via hydrolysis, magnesium hydroxide (Mg(OH)₂) is continuously generated and deposits on the surface of MgH₂,inhibiting the reaction and resulting in the actual amount of H₂ generated being significantly lower than the theoretical value. Additionally, the reaction is sensitive to temperature and exhibits slow kinetic. To address these challenges, we employed micro-alloying to introduce Zn elements and incorporated various g-C₃N₄catalysts to synergistically catalyze and modify MgH₂, thereby enhancing its hydrolysis performance. The MU-C₃N₄/MgH₂@5Zn sample demonstrated a hydrogen production capacity of 150.29 ml·0.1 g^-1at room temperature (25 °C), which is 5.3 times greater than that of Pure-MgH₂@5Zn (28.3 ml·0.1 g^-1). Concurrently, the conversion rate reached 92%, and the reaction rate was significantly improved. The enhanced hydrolysisperformance is attributed to the synergistic effects of microalloying and the efficient catalysis of g-C₃N₄, which not only accelerate the hydrolysis reaction but also effectively inhibit the formation of theMg(OH)₂ coating. The g-C₃N₄ catalyst employed in this study is characterized by its straightforward preparation, low cost, and environmental friendliness, allowing the reaction to proceed under mild conditions (25 °C). Furthermore, the microalloying process is easily achievable. Collectively, these factors underscore the potential for scalable and sustainable hydrogen production via MgH₂ hydrolysis in future applications.