First-principles study of electronic states, optical properties, water adsorption and dissociation properties of Pt-doped two-dimensional ZnO

•GGA + U method was used to evaluate the properties of 2D Pt-doped ZnO.•Pt dopant and vacancy can be formed under proper condition.•Pt and vacancy can tune the electronic and optical properties.•(Zn,Pt)O is a potential material for fabricating electronic, optical devices.•Water splitting is an important application for 2D (Zn,Pt)O. This research explores the electronic, optical, catalytic water adsorption and dissociation properties of two-dimensional ZnO with single and dual Pt doping using the first principles GGA + U method. The acquired formation energy result infers that the Pt dopant and vacancy can be obtained under an appropriate condition. Pt doping and vacancy can induce band levels and decreases the band gap of the two-dimensional ZnO. The decreased band gap enhances the light absorption in the visible light region, and therefore improves the visible energy utilization and expands the applicable range of ZnO. The water adsorption and dissociation properties of the two-dimensional Pt-doped ZnO are also studied in detail to explore its potential applications. These results show that the (Zn, Pt)O is a kind of promising electronic, optical, and catalytic material. The present investigation demonstrates the promising properties of Pt-doped ZnO for future applications, as well as stimulates related research.