Design of electrolyzer system and photocatalyst material for solar fuel

Abstract

The demand for alternative energy source is one of the most important problem intercepting the future of mankind. As a solution, solar light driven energy storage, especially by hydrogen, could be the best way to store energy and utilization. Conventionally, three different systems are designed to achieve hydrogen evolution by solar light under aqueous solution : photocatalyst, photoelectrochemical (PEC) electrode, and photovoltaic-electrosynthetic (PV-EC) cell. Here, we designed new photocatalysis material and PV-EC system for obtaining hydrogen from aqueous solution efficiently. Due to the methlyammonium lead iodide (MPI) tendency to be stabilized under low pH condition, especially under hydriodic acid, it would be possible for HI splitting reaction with solar light. Moreover, the band position is appropriate and the produced powder is also pure MPI. By applying visible light more than 475nm of wavelength, hydrogen evolution and I3- generation is detected without further degradation of MPI powder. Moreover, powder based treatment could enhance the photocatalytic activity. PV-EC system is most industrial-friendly system for future hydrogen evolution technique by solar light. In order to achieve high solar to hydrogen efficiency, superior photovoltaic and electrolysis system, especially well made catalyst is necessary. Moreover, in order to transfer the highest power of solar cell, converting technology is indispensable. Also, the converting technology can break the diode equation and produce higher current density by sacrificing maximum voltage. Water electrolysis cell is comprised of IrO2-MnO anode material and Pt/C cathode under acidic solution. Membrane electrode assembly technique is utilized with flow to produce highest electrolysis performance. By combining solar cell, converter and electrolysis cell, we could achieve 18.9% of solar to hydrogen efficiency.