Nanodiamond driven structure evolution of ZnO nanorods

Abstract

Spontaneous growth in ambient environment has become an exciting topic issue for nanostructured materials. Here, hydrothermally synthesized zinc oxide (ZnO) nanorods loaded with detonation nanodiamonds (DNDs) enable a spontaneous structure evolution related to a catalytic reduction of solid phase carbon of DNDs, being different from the traditional carbonaceous carbon dioxide gas (CO2). Exposed to ambient environment from days to weeks, the original ZnO nanorods placed on silicon substrate transfer to a concentric core–shell structure of ZnCO3/ZnO including abundant Zn/DND nanoparticles. A coaxial configuration with periodical multi-layered walls is formed, when the surrounding CO2 concentration is increased arising from supporting amorphous carbon film beneath. Importantly, the ZnO/DND nanorods are directly dissociated into DND@Zn core–shell nanoparticles in CO2-rich environment. The structural evolution from ZnO nanorods is attributed to DND having catalytic, reducibility, and hydrophilic hierarchical porosity structure with the participations of CO2 and H2O in air. This work demonstrates that based on the combination of ZnO and DNDs, a spontaneous growth process occurs, which provides a strategy for fabrication of novel nanostructures (not limited to ZnO nanorods). Furthermore, it offers a possibility for degradation of greenhouse gases by enhancing capture and decomposition of CO2 in ambient environment for carbon neutral.