Zinc Oxide Nanorods for Light-Activated Gas Sensing and Photocatalytic Applications

The demand for environmental monitoring and remediation stimulates tremendous research efforts to develop highly efficient and advanced functional nanomaterials capable of combining multiple functions with the arbitrary switching of application scenarios. However, there remains a lack of an in-depth and comprehensive understanding of the relationship between the multiple properties and the surface structure of the nanomaterials, which is crucial for the design and application of advanced functional nanomaterials. Here, we present a feasibility demonstration of a single ZnO nanorod-based material platform that uniquely synergizes several highly desired capabilities for gas sensing, optoelectronic, and photocatalytic applications. In such a nanomaterial platform, a research route and elaborate experiments uncover the surface structure–property relationships of the facet effect in conjunction with first-principles density functional theory calculations, identifying the defect effects of the dominant exposed (100) surfaces of the hydrothermally synthesized ZnO nanorods. The smaller diameter and higher density of the ZnO array remarkably promote the exposure area to the surrounding and surface oxygen vacancy amount as well as O 2 and H 2 O adsorption. Furthermore, the visible light absorption was enhanced by the raising valence band maximum position stemming from the enhanced surface oxygen vacancies. Importantly, this work offers unprecedented insights into the fundamental understanding of the essence behind the realization of multiple functions on a single nanomaterial platform, which could significantly boost the efficiency and reliability of miniaturized high-technology assets and other critical equipment, enabling the development and optimization of high-performance multifunctional electronics.