Engineering of electrodeposited binder-free organic-nickel hydroxide based nanohybrids for energy storage and electrocatalytic alkaline water splitting

Abstract

Organic-inorganic nanohybrids are widely used as electrode materials for various applications due to their high conductivity with porosity and tuneable nanostructures. However, the poor stability of organic-inorganic hybrid materials in aqueous alkaline electrolytes and the presence of binders restrict their use in various electrochemical applications such as energy storage and electrocatalytic water splitting. A class of electrodeposited binder-free organic-inorganic hybrid materials based on a benzo[2,1,3]selenadiazole-5-carbonyl N-capped dipeptide (BSeLW) and metal hydroxide (Ni(OH)2) are prepared for electrochemical applications. The binder-free electrodeposited nanohybrids grown on carbon paper (CP) ((1 : 20) BSeLW/Ni(OH)2/CP) are stable in aqueous 1 M KOH electrolyte solution and exhibit pseudo-capacitive behavior with a high charge storage efficiency of 742 F g-1 at 1.5 A g-1. A prominent 71% specific capacitance retention at 10 A g-1 after 1000 cycles indicates higher stability of dipeptide-based organic-inorganic nanohybrids on the carbon paper-based electrode surface. Additionally, the nanohybrid shows catalytic activity for electrocatalytic water splitting with a low overpotential for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline aqueous 1 M KOH solution. This work elucidates the rational engineering of organic-inorganic binder-free multi-functional nanohybrid electrodes as a favorable candidate for high-performance energy storage and electrocatalyst for electrocatalytic water splitting. © 2020 The Royal Society of Chemistry.