Band-structure tunability via modulation of planar buckling in ZnO monolayer: Manifestation in optoelectronic and photocatalytic properties

Two-dimensional ZnO materials, with their exceptional characteristics, hold great potential for novel nanoelectronic devices and catalysts. However, the strategy of modulating the electronic properties is still ongoing. To address this challenge, we conducted first-principles calculations to systematically investigate the structural stability, electronic properties and tunability of photocatalytic performance in ZnO monolayers with different planar buckling. The results indicate that ZnO monolayers with different buckling exhibit dynamical and thermal stability. The band edge positions of ZnO monolayers could be effectively controlled by planar buckling, and ZnO monolayers with suitable buckling can serve as potential candidates for visible-light driven water splitting for hydrogen generation. Furthermore, the narrowed band gaps in ZnO monolayers with increasing of planar buckling suggests their potential for use in the design of optoelectronic devices in nanoscale systems. In addition, the stability of buckled ZnO monolayers on Ag/Pt substrates and planar ZnO monolayer on semiconducting blue phosphorus (BlueP) are explored. Interestingly, Ag or Pt metal substrates have been found to be suitable for the growth of buckled ZnO monolayers. While BlueP monolayer is believed to serve as an excellent substrate for the growth of planar ZnO monolayers. These findings offer new strategy for designing planar or buckled ZnO monolayers with potential applications in futuristic nano-optoelectric and photocatalysis systems.