Harvesting Electronic Waste for the Development of Highly Efficient Eco-Design Electrodes for Electrocatalytic Water Splitting

Abstract

Disposal of e-wastes in prescribed landfills poses serious environmental concerns at both a local and global scale. Recovering valuable materials from e-wastes and utilizing them for development of eco-design devices guides one to a more productive way of managing wastes. Recycled copper is capable of retaining its intrinsic properties and can be reused with same expectation of performances; capitalizing on this fact, herein, it is attempted to utilize copper from e-waste as an economically viable catalytic substrate for overall water splitting. Upon deposition of amorphous nickel cobalt phosphide films, the scrap copper wires are highly efficient for catalyzing hydrogen and oxygen evolution reaction at low overpotential ((10)eta-(HER) = 178 mV, (10)eta-(OER) = 220 mV), and considerably promote water catalysis at 1.59 V@ 10 mA cm(-2). Moreover, the electrodes demonstrate long-term stability in alkaline electrolyte that can potentially be employed for large-scale electrolyzer application. The proposed electrode architecture, by the explicit growth of bimetallic phosphide on highly conductive Cu substrate, facilitates fast electron transport and promises a minimum contact resistance between electrocatalyst and current collector. This work paves the way for development of environmentally sound electrode materials from e-waste that can be exercised for a myriad of other clean energy reactions.