A multi-interface SnO2-Co3O4-Mo2S3 nanocomposite for enhanced electrocatalytic water splitting

In water splitting, the noble metal-based catalysts (IrO2, RuO2, Pt, etc.) are being replaced by non-noble, readily available, and cost-effective transition metal-based nanostructures. In the same pursuit, this work presents a novel bifunctional {Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER)} SnO2-Co3O4Mo2S3 multi-interface heterostructure nanocomposite. The SnO2-Co3O4-Mo2S3 nanocomposite, synthesized through facile sonochemical method, has a coupled morphology of coral-shaped nanoflowers modified with nanocubes. The significantly exposed surface area of this nanocomposite and the synergistic interactions among SnO2, Co3O4, and Mo2S3 were the cause of its interesting surface morphological characteristics and enhanced electrocatalytic activity. For OER and HER, overpotentials of 192.3 mV and 204.98 mV at 10 mA/cm2, and the significantly reduced Tafel slopes of 99 mV/dec and 102.8 mV/dec were obtained in 2.0 M KOH and 1.0 M H2SO4, respectively. This SnO2-Co3O4-Mo2S3 nanocomposite requires a cell voltage of 1.45 V only for water electrolysis at 10 mA/cm2. An extraordinary stability of 72 hours was noted for overall water splitting (OWS) while the current density barely changes. After the OWS, the SnO2-Co3O4-Mo2S3 nanocomposite modified electrode showed good stability, opening up novel possibilities for this multi-interface heterostructure SnO2Co3O4-Mo2S3 nanocomposite in the advancement of commercial energy-producing and energy-storage technologies.