Enhanced Charge Transport and Increased Active Sites on α?Fe2O3(110) Nanorod Surface Containing Oxygen Vacancies for ImprovedSolar Water Oxidation Performance

摘要

The effect of oxygen vacancies (VO) on α-Fe2O3 (110)facet on the performance of photoelectrochemical (PEC) water splittingis researched by both experiments and density functional theory (DFT)calculations. The experimental results manifest that the enhancement inphotocurrent density by the presence of VO is related with increasedcharge separation and charge-transfer efficiencies. The electrochemicalanalysis reveals that the sample with VO demonstrates an enhancedcarrier density and reduced charge-transfer resistance. The results ofDFT calculation indicate that the better charge separation is alsocontributed by the decrease of potential on the VO surface, whichimproves the hole transport from the bulk to the surface. The reducedcharge-transfer resistance is owing to the greatly increased number ofactive sites. The current study provides important insight into the rolesof VO on α-Fe2O3 photoanode, especially on its surface catalysis. Thegenerated lesson is also helpful for the improvement of other PEC photoanode materials.