Structure-property relationship in Fe₂O₃-MoS₂ and Fe₂O₃-MoS₂-rGO composites for hydrogen storage

This study reports the synthesis and hydrogen storage performance of Fe₂O₃-MoS₂-rGO ternary composites. Structural analyses confirm the formation of phase-pure α-Fe₂O₃, MoS_2, and rGO phases without impurities. X-ray photoelectron spectroscopy reveals strong interfacial interactions and stable chemical bonding between Fe₂O₃, MoS_2, and rGO. Morphological analysis confirms the uniform dispersion of nanosized Fe₂O₃ and MoS₂ (2-5 nm) anchored on rGO sheets, forming a mesoporous structure with an enhanced surface area (up to 98 m² g⁻¹). Hydrogen desorption studies reveal that the Fe₂O₃-MoS₂-rGO composites exhibit superior hydrogen release compared to pristine and binary samples. Notably, the FMG4 composition achieves the highest desorption capacity of 4.4 wt% at 523 K in 60 min. The reversible hydrogen storage capacity remains ∼4.26 wt% with only a minimal variation (±0.05) and capacity retention is 98.9% after 10 cycles, which indicates the sufficient reversibility and cycling stability. The improved hydrogen storage performance is attributed to the presence of rGO, which enhances hydrogen storage activity, provides additional adsorption sites, and facilitates reversible hydrogen sorption through a weak chemisorption mechanism.