Nanodiamond modification improves the n-butanol sensing performance of ZnO microspheres

ND-modified ZnO microspheres are prepared hydrothermally. • ZnO@ND1% shows a response of 52.43 to 100 ppm n-butanol at 160 °C. • DFT result reveals stronger n-butanol adsorption on ZnO@ND (−1.05 eV). Selective detection of volatile organic compounds is crucial for industrial safety and environmental monitoring. In this work, nanodiamond (ND) modified ZnO composites were prepared via a facile hydrothermal method to fabricate high-performance n-butanol gas sensors. The incorporation of ND effectively regulates the microstructure of ZnO, providing a larger specific surface area and abundant active sites for gas reaction. The optimized ZnO@ND composite exhibits a prominent sensing response of 52.43 toward 100 ppm n-butanol, which is nearly twice that of pristine ZnO, meanwhile reducing the optimal operating temperature to 160 °C. The enhanced sensing performance is mainly attributed to the synergistic effects of structural optimization and interfacial electronic modulation. Specifically, the increased surface area and chemisorbed oxygen content provide more accessible adsorption and reaction sites, and the ZnO@ND heterointerfaces facilitate charge transfer and accelerate the surface redox reaction with n-butanol. Density functional theory calculations prove the increased adsorption affinity toward n-butanol on ZnO@ND. As a result, the ZnO@ND sensor demonstrates excellent selectivity, favorable concentration-dependent response behavior, and reliable stability. This work proves that ND modification is an effective method to optimize the gas-sensing properties of ZnO, which provides a feasible reference for the development of high-efficiency metal oxide gas sensors. Download: Download high-res image (139KB) Download: Download full-size image