Cobalt Phthalocyanine Based Metal–Organic Framework as an Efficient Bifunctional Electrocatalyst for Water Electrolysis

Abstract

Water is the most convenient and facile fossil-free source for the production of hydrogen (H 2 ). Electrochemical water splitting is considered a promising and potential approach for accomplishing hydrogen frugality. Although water-splitting reaction is the most versatile and green technique, it accounts for only 4% of the universal H 2 production. The main hindrance in large-scale production is the sluggish kinetics of the reaction, which employs costlier and precious catalysts. In addition, the half-cell reactions for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water splitting require two different types of precious catalysts, which not only increases the cost but also decreases the efficiency due to the enhanced complexity of the system. Hence, designing an efficient, robust, nonprecious, earthabundant, and low-cost electrocatalyst capable of catalyzing both HER and OER during overall water splitting is an urgent requirement to meet the energy demand for sustainable growth. Here, a highly potential bifunctional electrocatalyst is fabricated using quinone-substituted cobalt(II) phthalocyanine (HQCoPc) with carbon nanoparticles (Ketjen black, KB). The organic hybrid of HQCoPc + KB modified on GCE and Ni foam showed remarkable electrocatalytic performance for HER and OER in acidic and basic conditions, respectively. The HQCoPc + KB composite affords a lower onset of 76 mV for HER and an overpotential of 234 and 360 mV at 10 mA•cm −2 for HER and OER, respectively, with superior stability for more than 40,000 s. The designed HQCoPc + KB bifunctional electrocatalyst not only offers a better catalyst for addressing a water-splitting reaction but also provides costeffectiveness and good chemical stability for sustainable energy technology.

Wastewater Utilization as a Source for Green Energy Generation Using Alkaline Water Splitting

“…The classic techniques of manufacturing hydrogen essentially include isolating hydrogen (H 2 ) from industrial waste products and byproducts of fossil fuel use. These methods, however, have a huge carbon footprint and cause environmental harm. , In contrast, it is believed that the creation of hydrogen using water electrolysis is more suited to generating high-purity hydrogen in a flexible, environmentally friendly, and renewable way. − …”