Dual-Functional Z-Scheme TiO2 @MoS2 @NC Multi-Heterostructures for Photo-Driving Ultrafast Sodium Ion Storage.

Exploiting dual-functional photoelectrodes to harvest and store solar energy is a challenging but efficient way for achieving renewable energy utilization. Herein, multi-heterostructures consisting of N-doped carbon coated MoS2 nanosheets supported by tubular TiO2 with photoelectric conversion and electronic transfer interfaces are designed. When a photo sodium ion battery (photo-SIB) is assembled based on the heterostructures, its capacity increases to 399.3 mAh g-1 with a high photo-conversion efficiency of 0.71 % switching from dark to visible light at 2.0 A g-1 . Remarkably, the photo-SIB can be recharged by light only, with a striking capacity of 231.4 mAh g-1 . Experimental and theoretical results suggest that the proposed multi-heterostructures can enhance charge transfer kinetics, maintain structural stability, and facilitate the separation of photo-excited carriers. This work presents a new strategy to design dual-functional photoelectrodes for efficient use of solar energy.