Polysaccharide derived carbon foams/sponges were synthesized via oxidation of simple sugars by metal nitrates leading to embedded metal particles within the carbon foam. Ni and Co in three different sugar (Xylose) to metal concentrations (20:1, 200:1, 2000:1) were varied to produce metal particles of different sizes. Carbon nanotubes (CNTs) were then grown on these carbon foams using embedded metal particles, both which have favorable carbon solubility properties, as catalytic substrates. Using two different metals, and three different precursor concentrations, undergoing the same synthesis process allows for six comparable CNT diameters. Deviations in particle size and therefore CNT diameter may be a result of differences in carbon solubility, precursor concentration, among other controlled variables such as processing temperature and time. SEM micrographs allow for accurate measurement of CNT diameters and sufficient sample size for statistical analysis to reliably identify significant trends in CNT sizes based off varying metal substrates and substrate concentrations. This data may provide insight into control of CNT diameters in addition to properties such as chirality towards applications pertaining to capacitors, gas sensors, hydrophobic or oleophilic coatings.