Hierarchically assembled 2D material membranes are extremely promising platforms for energy conversion processes in nanofluidics. In this perspective, we discuss recent advances in the production of smart 2D material membranes that come close to mimicking biological energy conversion processes and how these efforts translate into the design of water purification systems, artificial photosynthesis, and solar energy conversion devices. As we depict here, 2D material membranes synergistically modulate the intrinsic active sites (nanopores), electron transport, mass transfer, and mechanical and chemical stability aiming at cost-effective and highly efficient smart membranes.