H2 as Clean Energy for Sustainable Future

Abstract

H₂ is considered a clean fuel used in Fuel cell technology for electricity generation with zero greenhouse gas (GHG) emission. The demand for H₂ gas, typically for fuel cell electric vehicles (FCEVs), is increasing. However, the current H2 production relies on natural gas and coals related to carbon oxide gas emission, which gives back to global warming concerns. Low-carbon production processes are needed to contribute to the United Nation's sustainable development goals (SDGs). Water-splitting reaction using photocatalysis or electrocatalysis is a promising method for producing H₂ from water, which is the earthabundant resource. These H₂ production methods based on catalytic technologies require highly active catalyst materials with long-term stability. The development of non-conventional materials with consideration of nanostructure, multijunction, and defect engineering is explored to achieve highly active catalyst materials. This mini-review discusses a basic understanding of H₂ production from water-splitting reactions via photocatalysis and electrocatalysis, with outstanding examples of recent works reported. Last part, we provide a short study on the H₂ global market and policy in order to conclude the future direction of H₂ energy.