Researchers from the Institute of Industrial Science at The University of Tokyo have made significant progress in determining the location of hydrogen in titanium hydride nanofilms. Hydrogen, despite being the smallest atom, plays a crucial role in affecting the properties of materials. The study aimed to find a reliable method to locate hydrogen in nanofilms, essential for applications like hydrogen storage. The team's approach involved using nuclear reaction analysis (NRA) and ion channeling to create a two-dimensional map of hydrogen isotopes in the nanofilms. By examining a TiH1.47 nanofilm, they were able to precisely identify the locations of hydrogen and deuterium atoms. Notably, the presence of hydrogen at octahedral sites and deuterium at tetrahedral positions offered insights into stabilizing the lattice structure. The ability to differentiate between hydrogen isotopes opens up possibilities for fine-tuning the properties of nanofilms based on specific applications. This discovery could have practical implications in controlling hydrogen-induced phenomena, contributing to advancements in hydrogen storage, solid electrolyte, and heterogeneous catalysis technologies. Overall, the research sheds light on the intricate behavior of hydrogen isotopes in titanium hydride nanofilms, providing a foundation for future developments in green solutions and material applications.