Abstract
In this work we propose a simple methodology to fabricate monometallic nickel [Ni] and bimetallic silver-nickel [Ag/Ni] deposited flexible, self-supported electrodes using polyester (commonly used as overhead projector [OHP]) films. Monometallic Ni is deposited onto chemically modified OHP sheets using a simple electroless deposition process. Similarly bimetallic Ag/Ni coating is carried out by employing galvanic replacement reaction (GRR) of silver onto Ni coated polyester films. Structure, morphology, composition and crystalline phase characteristics of these monometallic and bimetallic deposited flexible electrodes are analyzed by using a variety of spectroscopic and microscopic techniques. Electrochemical characteristics corresponding to hydrogen evolution reaction (HER) are investigated by using linear sweep voltammetry (LSV), Tafel polarization and impedance spectroscopic studies. Effect of time duration associated with GRR on the structural morphology of resultant deposits and on their HER electrocatalytic activity is also investigated. These studies reveal that compared to monometallic Ni, bimetallic Ag/Ni deposited flexible electrodes exhibit enhanced electrocatalytic performance for HER due to strong synergistic effect of bimetallic heterostructures. Among the various electrodes investigated, bimetallic Ag/Ni coated flexible polyester films obtained through 5 minutes of GRR show a higher electrocatalytic activity for HER. These results provide a platform towards the development of alternative electrodes for HER using simple and affordable techniques that play a significant role for further advancement of alkaline water electrolysis.