Title : IrO2-modified RuO2 nanowires/nitrogen-doped carbon composite for effective overall water splitting in all pH
Abstract:
Hydrogen(H2) is a promising alternative energy source, but its current production method through steamer forming is energy intensive and polluting. Water electrolysis, specifically the oxygen evolution reaction (OER)and hydrogen evolution reaction (HER), offers a cleaner option. Development of active catalysts for HER and OER are of prime importance for the commercialization of the proton-exchange membrane (PEM)/anion-exchange membrane (AEM) water electrolyzer. In our recent work, we synthesized IrO2-modified RuO2 nanowires/nitrogen-doped carbon composite for overall water splitting at all pH. This catalyst exhibits excellent OER activity in 0.5 M H2SO4 solution with a low overpotential of 188 mV at 10 mA/cm2 current density, a low Tafel slope value of 42 mV/dec, and∼96% faradic efficiency. The OER of this catalyst in neutral and base media is also higher than that of commercial RuO2 and IrO2. IrO2−RuO2/C also showed very good HER activity with 10 mA/cm2 current density at 82 and 75 mV overpotential in acid and base, respectively. The HER performance of this catalyst is better than that of commercial Pt/C in base and slightly lower in neutral and acid. The catalyst shows excellent OER and HER stability compared to the state-of-art catalysts. In addition, the overall water-splitting performance of IrO2−RuO2/C was also studied, which shows 10 mA/cm2 current density at 1.52 and 1.51 V cell voltage in 1.0 M KOH and 0.5 MH2SO4, respectively. The outstanding activity of the IrO2−RuO2/C catalyst can be attributed to a unique one-dimensional nanowire structure, synergistic interaction, high surface area, high oxophilicity, and high mass and electron transportation between IrO2, RuO2, and the carbon support.
Audience Takeaway Notes:
- The electrochemical method can produce highly pure hydrogen (H2).
- This synthesis method of nanomaterials can be applied to synthesis other nanostructured materials and can be applied in the field of catalysis.
- One dimensional morphology, oxophilicity and synergistic interaction among different components helped to improve overall water splitting performance of the catalyst.
