Materials are the key roadblocks for the commercialization of energy conversion devices in fuel cells andsolar cells. Significant research has focused on tuning the intrinsic properties of materials at the nanometerscale. The soft template mediated controlled fabrication of advanced nanostructured materials isattracting considerable interest due to the promising applications of these materials in catalysis and electrocatalysis.Swollen hexagonal lyotropic liquid crystals (SLCs) consist of oil-swollen surfactant-stabilized1D, 2D or 3D nanometric assemblies regularly arranged in an aqueous solvent. Interestingly, the characteristicsize of the SLCs can be controlled by adjusting the volume ratio of oil to water. The non-polarand/or polar compartments of the SLCs can be doped with guest molecules and used as nanoreactorsfor the synthesis of various metals (Pt, Pd, Au, etc.), conducting polymers and composite nanostructureswith controlled size and shape. 1D, 2D and 3D mono- and bimetallic nanostructures of controlled compositionand porosity can also be fabricated. These materials have demonstrated impressive enhancementsof their electrochemical properties as compared to their bulk counterparts and have been identifiedas promising for further implementation in energy harvesting applications. In this review article,recent research materials are described regarding the development of functional materials with muchimproved performances for catalysis applications. This review addresses a brief overview of swollen hexagonalmesophases as nanoreactors, describes examples of nanostructured materials synthesized inthese nanoreactors, shows several examples of the energy conversion applications in solar light harvesting,fuel cells etc. and also summarizes the associated reaction mechanisms developed in the recent literaturefor enhanced catalytic activity.