The solar-driven photocatalytic splitting of water into hydrogen and oxygen is a potential source of clean and renewable fuel. However, four decades of global research have proven this multi-step reaction to be highly challenging. Here, I will present our strategies, and most recent results, in taking photocatalyst production to new and unexplored frontiers, while exploring solar to chemical conversion that goes beyond water splitting. I will focus on unique design of innovative nano scale particles, which harness nano phenomena for improved activity, and methodologies for the construction of sophisticated heterostructures. I will share our design rules and accumulated insights, which enabled us to demonstrate efficient, and stable, full-cycle endothermic redox transformations, realizing a genuine solar-to-fuel energy conversion, with state of the art efficiencies of up to 4.2%.