Imagine assembling thousands of wheels into a machine capable of taking full advantage of sustainable solar energy to readily satisfy the burgeoning energy demand of humanity for millennium.  Although wheels are not molecules, Nature has done exactly that, assembling chlorophyll and carotenoid as the pigments, manganese–calcium oxide cluster as the catalyst, and so on into the sophisticated chloroplast to convert renewable sunlight into chemical fuels to power living organisms for billions of years. Understanding how the remarkable functionality of such a biomachinery come about from the synergistic effect of those components and further using this knowledge to design a synthetic system, which consists otherwise of inorganic compounds that, however, obey the same laws of physics as those molecules and exceeds in the performance of its biological counterpart, have long been the central thrust of my research group. Another central theme has been to develop the post–lithium electrochemical energy storage technologies, e.g. rechargeable aqueous battery, and the supercapacitor, to address (i) the safety issue resulted from the thermal runaway caused by the reactivity of the electrode material with the flammable organic electrolyte and (ii) the mismatch in the energy and power densities reported for the electrodes and devices, respectively. My contribution to the aforementioned two fields have been made by leveraging my expertise in the chemical synthesis of novel functional nanomaterials and their controllable integration into well–designed multi–junction heterostructures as the electroactive materials and photoelectrocatalysts, which will be discussed during my presentation.