▎ 摘　　要

Depleting fossil fuels and greenhouse emissions render hydrogen (H) a promising alternative for powering automobiles. MgH2 with its promising H-weight capacity approximate to 7.6 wt% can be used for this purpose. However, it exhibits long incubation times with no significant H-release during the early stages. The present Mg-B-reduced graphene oxide (rGO) nanocomposites can reduce such incubation time drastically. Herein, Mg, rGO, and elemental B as a light weight catalyst at various proportions (viz. B/C (from rGO) weight ratios of 0, 0.09, 0.22, 0.36, and 0.90) are used to synthesize Mg-B-rGO nanocomposites by ball milling. They are eventually subjected to hydrogen uptake at approximate to 320 degrees C and P-H2 approximate to 15 bar followed by H-release in vacuum. The nanocomposite with B/C approximate to 0.22 exhibits remarkably negligible incubation time (approximate to 43 s) vis-a-vis approximate to 11 min by B/C = 0. This B/C approximate to 0.22 nanocomposite experiences charge (electron) transfer from Mg and B to C, located external to MgH2 unit cell. This causes Mg <- H -> B "Tug-of-war" within MgH2 unit cell, containing B in its interstitials (due to ball milling) and shrinking it. This leads to "structural catalysis" of H-release, understood by X-ray photoelectron, valence band, Raman spectra, and novel electron density maps. These novel materials can alleviate the need for activation cycles for their application.