1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM]Tf2N) was investigated as a multifunctional solvent, ligand, and reducing agent for platinum deposition onto well-defined CdSe@CdS nanorods. Platinum deposition was carried out thermally and photochemically using Pt(acac)2 as the metal precursor. Thermal deposition was investigated in [BMIM]Tf2N with and without addition of a sacrificial reducing agent, and product topology was compared with the products obtained from polyol reduction using 1,2-hexadecanediol, oleic acid, and oleylamine in diphenyl ether. Photochemically induced platinum deposition was carried out at room temperature in [BMIM]Tf2N, and product topology was compared with the photodeposition products obtained from a toluene dispersion. Thermal deposition of platinum in ionic liquid showed rods of broken morphology and small platinum nanoparticles speckled across the rods’ surface, while photodeposition of platinum exhibited particles decorated throughout the nanorod surface but larger in size than those exhibited by thermal means. Photocatalytic reduction of methylene blue was studied using these Pt-CdSe@CdS heterostructured nanoparticles, and catalytic performance was correlated with topology and synthetic history. Initial findings of catalytic performance suggest that there in an advantage of depositing platinum nanoparticles onto the CdSe@CdS in the ionic liquid system. Methylene blue dye was degraded using each system and the results show and there is an increased performance of the nanorods synthesized in the ionic system.