Photoelectrochemical System for Hydrogen Generation

One of the barriers to a hydrogen economy is the absence of a cost effective method of producing clean hydrogen. The direct electrolysis of water using solar energy (e.g., a photoelectrochemical process) would be ideal. However, this solution requires new semiconductor photoelectric materials with high energy conversion efficiency and high durability, along with the ability to cost-effectively synthesize these materials. This project will develop a new method of inexpensively synthesizing, processing, and stabilizing semiconductor photoelectric materials that can satisfy the performance criteria for photoelectrochemical cells. The approach is based on the electrochemical deposition of A2B6-based semiconductor heterojunctions, both n-type anode and p-type binary cathode. In Phase I, the system was designed and its feasibility demonstrated through simulation and a series of proof-of-concept experiments, including the validation of fabrication steps. The results suggested a hydrogen-production efficiency greater than 12% with a durability longer than 5000 hours. Phase II will involve optimization of the design, exploration of more A2B6 semiconductor films, maturation of the electrodeposition process, and development of a fully functional prototype. The prototype will be tested at a national laboratory to demonstrate its conversion efficiency, durability, and economic viability. Commercial Applications and Other Benefits as described by the awardee: The semiconductor-based photoelectrochemical system for generating hydrogen by solar energy conversion should significantly increase the efficiency of hydrogen production in industrial processes, in particular for hydrogen-hungry industries such as transportation. Other applications include autonomous, highly reliable, no-power sources for hydrogen fuel; augmentation of solar power generation; production of hydrogen for fuel cells; and the spin-off application for fabricating solar photovoltaic cells.