Strontium-based nanoparticles (NPs) find applications in energy storage, electronics, optoelectronic devices, lightning, FETs, LEDs, television screens, display units, fabrication of sensors, wastewater treatment, vehicles of space and navigation, remote weather stations, and in the field of medicine (antibacterial agents, tissue engineering, orthopedics, bone regeneration, bone health, and in the treatment of osteoporosis, etc.). Recently, plant-mediated green synthesis of NPs has gained significant attention due to its eco-friendly, sustainable, and cost-effective approach. The green production of strontium oxide (SrO) NPs is rarely reported in earlier literature, which is the focus of the current study. We synthesized SrO_aq and SrO_et NPs by utilizing the aqueous and ethanolic extracts of Cymbopogon citratus (lemon grass). The synthesized NPs were analyzed by FTIR, X-ray diffraction (XRD), and UVvisible spectroscopies. FTIR analysis showed the presence of organic moieties and characteristic Sr-O bands. UV-visible spectroscopy displayed an absorption peak at 298 and 298.9 nm in SrO_aq and SrO_et, respectively. SrO_et exhibited a smaller band gap (4.25 eV) than SrO_aq (4.47 eV). The synthesized NPs possessed well-defined crystalline structures and exhibited good electrocatalytic performance for water splitting. SrO_et was found to be a more effectual electrocatalyst for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) due to its higher electrochemically active surface area (EASA) and smaller charge transfer resistance (R_ct = 60Ω) than those of SrO_aq. The investigated NPs displayed promising redox behavior, charge storage capacity, and catalytic efficiency, highlighting their potential usage in energy storage and electrocatalytic water splitting.