Interface engineering in hexagonal boron nitride/metal systems: from in situ growth to metal matrix composites

Hexagonal boron nitride (h-BN) exhibits unique physicochemical properties, and the interfaces it forms with metals are crucial for the development of next-generation electronic devices, catalysts, and high-performance composite materials. This review focuses on interface engineering within h-BN/metal systems, systematically analyzing the interfacial characteristics associated with two primary approaches: in situ growth and ex situ compositing. Specifically, during the in situ growth of h-BN thin films on metal substrates, the metal substrate and growth conditions exert multifaceted influences on film quality through interfacial coupling. For ex situ preparation of h-BN/metal composites, interface construction is synergistically determined by h-BN dimension, matrix properties, and the fabrication process. This review aims to elucidate the fundamental principles and unique mechanisms of h-BN/metal interface control, thereby providing strategic insights for the designing and optimizing advanced h-BN-based functional devices and composite materials.