Background Hydrogen has been considered one of the most promising alternative fuel due to its high gravimetric energy density, low greenhouse gas emission, and ease of storage. Solar hydrogen production by water splitting in a photo-electrochemical cell (PEC) enables direct conversion of solar to fuel energy. To realize economical solar hydrogen production,...

Proton Exchange Membrane Fuel Cells (PEMFCs) provide electricity by using hydrogen as fuel and expelling heat and water as exhaust. PEMFCs are the promising power sources for automotive, stationary and mobile electronics because of their higher power densities and environmental benefits and hence they have attracted enormous interest. Unfortunately,...