Which of the following is NOT a use of fullerenes?

Fullerenes are a form of carbon molecular structures that have unique properties, leading to various applications in different fields. One noteworthy aspect of fullerenes is their ability to form complex interactions with other molecules, making them suitable for applications such as drug delivery systems, where they can encapsulate drugs and target them directly to specific cells.

In the context of industrial catalysts, fullerenes can facilitate chemical reactions by providing a unique surface area and structure, which enhances efficiency in various industrial processes. Their lubricating properties also come into play, as fullerenes can reduce friction at a molecular level, making them useful as lubricants in some mechanical applications.

However, while fullerenes have a multitude of applications, they are not typically used to make fuel for vehicles. Traditional fuels are derived from hydrocarbons, and, although there is ongoing research into alternative fuels, fullerenes themselves do not serve as a direct energy source for vehicular fuel. This distinction highlights the fact that while fullerenes have innovative uses, making fuel for vehicles does not fall into their application spectrum.