| Summary: | 碩士 === 國立中央大學 === 機械工程學系 === 105 === Solar hydrogen production is one of the promising methods for hydrogen generation. In photoelectrochemical method, hydrogen is generated by using a water-splitting device composed of a photoanode and a photocathode immersed in electrolyte (KOH, H2SO4, etc). To achieve this goal efficiently, the material of photoelectrodes should have properties of appropriate band edges, small bandgap, great electron (hole) conductivity, high chemical stability and high natural abundance. Hematite has great properties of appropriate bandgap and high chemical stability, but short carrier diffusion distances and conduction band below water reduction level limit its performance. Therefore, we proposed a strategy including optimization of carrier density in hematite photoanode and modification of surface state position using pulsed laser deposition (PLD) and solution-phase deposition (SPD). The optimal samples showed the onset potential of 0.85 V (vs. RHE) and current density of 0.55 mA/cm2 at 1.4 V (vs. RHE).
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