A sample of Au loaded macadamia shell based carbon activated at 1000 C was further analysed using SEM and EDAX. The SEM images are presented in Fig. 4a and b: while the EDAX analysis revealed the presence of Au on the loaded sample, see Fig. 4d, the absence of Au on the unloaded macadamia shell based carbon was confirmed in Fig. 4c. Furthermore, elemental mapping of the carbon surface and identification of Au sites were conducted on the Au loaded macadamia shell based carbon. The presence of adsorbed Au on the surface of the macadamia shell based carbon can be easily seen in the EDAX spectra, Fig. 4d. The Au deposits were not just restricted to the macroscopic features, which could be easily identified within the instrument resolution (1 mm to 0.5 lm), but they were widely distributed throughout the structure as seen in Fig. 5c. These results are consistent with microtomography studies of Dai et al., which reveal a uniform distribution of Au throughout the carbon structure of activated carbon materials (Dai et al., 2008).