Nano-Si for On-Demand H₂ Production: Optimization of Yield and Real-Time Visualization of SiDH₂O Reaction Using Liquid-Phase Transmission Electron Microscopy

Hydrogen (H-2), the most abundant element in the universe, has the potential to address the challenges of energy security and climate change. However, due to the lack of a safe and efficient method for storing and delivering hydrogen, its practical application is still in its infancy stages. To overcome this challenge, a promising solution is demonstrated in the form of on-demand production of H-2 using nano-Silicon (Si) powders. The method offers instantaneous production of H-2, yielding a volume of 1.3 L per gram of Si at room temperature. Moreover, the H-2 production yield and the rate can be effectively controlled by adjusting the reaction pH value and temperatures. Additionally, liquid-phase transmission electron microscopy (LPTEM) is utilized in situ to demonstrate the entire reaction in real-time, wherein H-2 bubble formation is observed and illustrated the gradual conversion of crystalline Si particles into amorphous oxides. Moreover, it is confirmed that the purity of the generated gas is 99.5% using gas chromatography mass spectrometry (GC-MS). These findings suggest a viable option for instant H-2 production in portable fuel cells using Si cartridges or pellets.