CdS/ZnFe<sub>2</sub>O<sub>4</sub> Core–Shell Nanorod Arrays on Modified TiO<sub>2</sub> Photoanodes for Photoelectrochemical Water Splitting
Qingping Dai, Yumin Li, Zhibin Qiu, Hongwei Tian, Yuanmao Pu, Xuan Chen, Bing Lv, Jun Wei, Wenzhong Wang
Abstract
The photoelectrochemical (PEC) photoanode is highly expected to address the energy crisis and environmental pollution in the future. Herein, a ternary heterojunction photoanode with well-designed morphology and stair-like band alignment has been successfully fabricated by growing CdS/ZnFe 2 O 4 core–shell nanorod arrays (NRAs) on the tops of TiO 2 NRAs (TiO 2 /CdS/ZnFe 2 O 4 ). The light harvesting ability and PEC performance of the TiO 2 /CdS/ZnFe 2 O 4 NRAs photoanode are significantly augmented, as optimized TiO 2 /CdS/ZnFe 2 O 4 yields a remarkable photocurrent density of 4.75 mA/cm 2 and a significant applied bias photon-to-current efficiency of 3.00%, which are 8.6 and 9.1 times those of the unmodified TiO 2 NRAs photoanode, respectively. The substantially boosted PEC performance is attributed to efficient charge transfer and separation achieved by the staircase-like band structure between TiO 2, CdS, and ZnFe 2 O 4 . This excellent scheme provides an avenue to construct an efficient TiO 2 -based photoanode with special morphology and stair-like band alignment for the PEC water splitting field.