Reversible hydrogen storage performance of titanium dioxide/reduced graphene oxide (TiO2/rGO) composite

Hydrogen storage in solid-state metal oxide systems is constrained by low gravimetric capacity and limited surface-active sites for hydrogen dissociation. This work addresses these limitations and explores the hydrogen storage behaviour of titanium dioxide/reduced graphene oxide (TiO 2 /rGO) composites with systematically varied rGO content (5 wt% and 10 wt%). TiO 2 nanoparticles are synthesized by the sol-gel method, rGO nanosheets are prepared by the modified Hummer's method and, TiO 2 /rGO composites (TiO 2 /rGO-5wt% and TiO 2 /rGO-10 wt%) are prepared by wet-impregnation technique. Structural, morphological, spectroscopic, and surface textural characterizations are systematically carried out. Hydrogenation experiments are conducted at 10 bar and 100 °C followed by dehydrogenation to confirm reversibility. The hydrogen storage capacities of TiO 2 , TiO 2 /rGO-5wt% and TiO 2 /rGO-10 wt% are 1.07 wt%, 1.40 wt% and 1.60 wt%, respectively. Notably, the 1.60 wt% capacity achieved by TiO 2 /rGO-10 wt% represents a 50% improvement over bare TiO 2 and exceeds values reported for TiO 2 – based composites under comparable storage conditions.