Heterojunction Engineering for Electrocatalytic Applications

Production of green hydrogen from the electrolysis of water is considered to be one of the most desirable processes to address the clean energy demand. However, a high energy barrier and an economically unsustainable nature limit the process toward practical implementation in an extensive way. The designing of an electrocatalyst accompanied by defect engineering, heteroatom doping, and strain creation are known to be effective strategies to make the process efficient. Recently, construction of heterojunctions with a combination of materials with desired band structures is considered to be a smart approach in promoting electrocatalytic activities by attaining charge redistribution and manipulating the electronic structure at the interface. The present review elaborately discusses possible heterojunctions, alterations at the interface, insight thermodynamics, and possible causes for boosting electrocatalytic activities. The heterojunction-based electrocatalysts are found not only effective for oxygen evolution reactions and hydrogen evolution reactions, but also to be very useful toward various electrochemical oxidation reactions as well as electrochemical reduction reactions involving small molecules undergoing decomposition at very low energy. Having such a specialty, there is no doubt that heterojunction-based electrocatalysts are going to be the primary choices of researchers in coming years.