Atomically-thin WO3/TiO2 heterojunction for supercapacitor electrodes developed by atomic layer deposition

•2D WO3/TiO2 heterojunction was first demonstrated for supercapacitor electrodes.•WO3/TiO2 heterojunction has a uniform thickness of ~ 12 nm with rough surface.•Specific capacitance of 625.53 F g-1 and retention of 97.98% were achieved.•This work represents a general fabrication approach of 2D large-scale electrodes.

In this study two-dimensional (2D) WO3/TiO2 heterojunction developed by atomic layer deposition (ALD) technique has been demonstrated for the first time for supercapacitor (SC) electrodes. This 2D heterojunction has a uniform thickness of ~ 12 nm with relatively rough surface. The electrode based on WO3/TiO2 heterojunction shown excellent super-capacitive behaviors with high specific capacitance up to 625.53 F g-1 at the current density of 1 A g-1 and long-term stability of 97.98% over 2000 cycles. The present work could represent the general approach towards the large-scale fabrication of 2D heterojunction electrodes for high-performance SCs.