Manipulating Electron Structure through Dual-Interface Engineering of 3C-SiC Photoanode for Enhanced Solar Water Splitting
Hui Zeng, Satoru Yoshioka, Weimin Wang, Zhongyuan Han, Ivan G. Ivanov, Hongwei Liang, Vanya Darakchieva, Jianwu Sun
Abstract
High Resolution Image Download MS PowerPoint Slide Interface engineering is crucial for enhancing the efficiency of semiconductor-based solar energy devices. In this work, we report a novel dual-interface engineering strategy by designing a Ni(OH) 2 /Co 3 O 4 /3C-SiC photoanode that achieves remarkable enhancements in photoelectrochemical (PEC) water splitting performance. The optimized photoanode delivers a photocurrent density of 1.68 mA cm –2 at 1.23 V vs the reversible hydrogen electrode (RHE), representing an 8-fold increase compared to pristine 3C-SiC, along with excellent operational stability. In this architecture, Co 3 O 4 serves as a highly efficient hole-extraction layer and forms a p–n junction with 3C-SiC, enhancing the separation of photogenerated electron–hole pairs. At the Ni(OH) 2 /Co 3 O 4 interface, the formation of Ni–O–Co bonds facilitates rapid charge transfer and accelerates oxygen evolution reaction (OER) kinetics. The microwave photoconductivity decay (μ-PCD) measurements confirm a prolonged minority carrier lifetime, demonstrating the critical role of electronic structure modulation in improving charge separation and reducing recombination. Using advanced synchrotron radiation and X-ray absorption spectroscopy, we unveil critical modifications to the interfacial electronic structure induced by the dual-interface engineering and their roles in enhancing PEC performance. These findings establish a clear relationship between electronic structure modulation, charge carrier dynamics, and PEC performance, providing new insights into interface design strategies for highly efficient solar-driven water splitting systems.