A review on hydrogen generation by phthalocyanines

Abstract

Hydrogen, the most abundant element in the universe, holds a great promise as an alternative to conventional fuels. Among various approaches, the renewable energy-driven electro- and photocatalytic generations have lately gained prominence owing to the plethora of advantages that they offer. It is evident that when employing these methods for the H 2 production, catalyst is one of the significant components of the reaction, determining how much H 2 could be evolved by the proposed system. This has led to a rise in the number of scientific papers devoted to the development of novel and active catalysts as potential candidates for catalyzing the hydrogen evolution reaction. In this regard, phthalocyanine (Pc)-based catalysts offer powerful pathway due to the particular properties, including the ease of large-scale manufacturing, unique redox behavior, high efficiency, ease of separation, and recyclable nature. In this review, we have provided a comprehensive overview of publications on the generation of hydrogen by electrolysis and photolysis of various substrates, both of which are accomplished through the use of a variety of Pc-based catalysts. A number of critical variables were discovered to be consequential for the ultimate H 2 generation rate in the catalytic H 2 evolution systems such as the effects of metal center, substitution, support, size, and crystallinity of Pc. • The renewable energy-driven electro(photo) catalytic hydrogen production. • Phthalocyanine-based electro(photo) catalysts for green hydrogen generation. • Water splitting towards hydrogen evolution. • Phthalocyanines as photosensitizer, semiconductor, and catalysts in hydrogen evolution.