Surface Decoration of DNA-Aided Amorphous Cobalt Hydroxide via Ag+ Ions as Binder-Free Electrodes toward Electrochemical Oxygen Evolution Reaction.

Out of various available methods, generation of hydrogen by electrocatalytic water splitting is the most accepted one which consists of two half-cell reactions, viz, oxygen evolution reaction (OER) at the anode and hydrogen evolution reaction at the cathode. OER is a complex four-electron transfer process, and to sustain the spontaneous generation of hydrogen at the cathode, it is urgent to develop some earth-abundant, low-cost electrode materials. Recently, use of cobalt-based hydroxide as the electrode substrate has taken much consideration and has been fabricated over various substrates. Because of various structural disorders, internal resistance, and dependence on the electrode, the binder substrate makes their applications limited. Here, in this work, to remove structural disorder and to increase electrical conductivity, we have incorporated silver ions into amorphous Co(OH)2, which turns to be a highly active OER electrocatalyst. Also, for the first time, we have developed hydroxide-based materials by using DNA as a stabilizer, and most importantly, using DNA gives an immense opportunity to run long-term OER applications without using an external binder such as nafion. Moreover, for the first time, these DNA-based materials were coated on nickel foam mainly to eliminate the low conductive nature of Ag2O. The synthesized catalyst showed a very high OER activity, and to reach 50 mA/cm2 current density, it needs only 260 mV as overpotential. The amorphous nature of hydroxide-based materials gives a higher opportunity toward the electrolyte to bind on the surface of a catalyst to run the OER with less applied overpotentials.