Hydrogen permeation barriers and preparation techniques: A review

In the hydrogen energy industry, penetration of hydrogen into storage and transportation materials is a big problem because the process causes cracks, equipment damage, hydrogen leakage, failure, and even explosion. Hydrogen permeation barriers are, thus, necessary to improve the hydrogen resistance of materials and new coating materials and fabrication techniques are being explored. In this review, recent progress in the research of hydrogen permeation barriers is reviewed in terms of both the materials and preparation technology. The current research progress is first discussed based on traditional barriers such as metals and ceramics. Recent development of two-dimensional materials and composite coatings is described and the hydrogen resistance mechanism is discussed. The advantages and limitations of six common preparation methods: physical vapor deposition, chemical vapor deposition, solgel method, plasma spraying, electrochemical deposition, and plasma electrolytic oxidation are compared. Novel composite coatings with "hydrogen storage and barrier " structures are attractive and constitute one of the future research directions. Published under an exclusive license by the AVS.