Electronic structure and enhanced photocatalytic properties in Ca(OH)2/GeC van der Waals heterostructure

Two-dimensional (2D) van der Waals heterostructures (vdWHs) show great potential applications in the field of electronic and optoelectronic devices. In this work, first-principles calculations under hybrid HSE06 functional are performed to explore the electronic and optical properties of Ca(OH)(2)/GeC vdWH. Our results show that the Ca(OH)(2)/GeC vdWH owns a direct band gap of 2.73 eV, which is smaller than that of GeC monolayer. Meanwhile, this vdWH shows improved ability to absorb visible light and high-energy photons compared with the Ca(OH)(2) and the GeC monolayers. The valence band maximum (VBM) potential of Ca(OH)(2)/GeC is lower than that of GeC, which means that the Ca(OH)(2)/GeC vdWH has better oxidation than that of the GeC monolayer. On the other hand, the Ca(OH)(2)/GeC vdWH also satisfies the requirement for photocatalytic overall water splitting. These findings indicate that Ca(OH)(2)/GeC vdWH is a promising candidate for optoelectronic devices and photocatalysis.