One-pot synthesis of a high performance chitosan-nickel oxyhydroxide nanocomposite for glucose fuel cell and electro-sensing applications

This study introduces an alternative promising Pt-free catalyst of chitosan-nickel oxyhydroxide nanocomposite (nano-CS-NiOOH) with outstanding activity and durability towards glucose electrooxidation (Gox) and oxygen reduction reaction (ORR) compared to precious metal-based catalysts. Nano-CS-NiOOH modified glassy carbon (GC) electrode (nano-CS-NiOOH/GC) exhibits superb electrocatalytic activity, molecular selectivity and long-term durability for Gox. For instance, nano-CS-NiOOH/GC electrode shows ca. 10 times higher electrocatalytic activity and stability for Gox compared to nano-NiOOH/GC electrode with the same NiOOH weight. Additionally, the nano-CS-NiOOH/GC electrode exhibits a glucose sensitivity of 687 mu A mM(-1) cm(-2), which is 34-fold greater than that obtained at the nano-NiOOH/GC electrode (20 mu A mM(-1) cm(-2)) with lowest detection limit of 20 nM based on a sighal-to-noise ratio of 3 and a linear range up to 8 mM. Furthermore, nano-CS-NiOOH/GC electrode showed a superior electrocatalytic activity and durability for both ORR and OER in alkaline medium compared to the commercial Pt/C electrode making it a high-performance non-precious metal-based bifunctional catalyst. NiOOH is believed to play a crucial role as a catalytic mediator to facilitate the charge transfer and chitosan is thought to enhance the catalytic activity and durability via stabilizing beta-NiOOH and improving the adsorption of active species through its -NH(2)and -OH like functionalities. (C) 2016 Elsevier B.V. All rights reserved.