Table 1. Results of elemental analysis of Ru-halloysite core-shell structures shown in Figure 3(b). Total mass of 100% does not include copper which is not part of the nanotubes.

Element	Energy, keV	Counts, ± 10	Mass, wt%
O K	0.525	53,544	40.6
Al K	1.486	39,007	13.8
Si K	1.739	47,374	33.7
Fe K	6.398	1505	1.2
Cu K	8.04	23,157	–
Ru L	2.558	6592	10.7
Total			100