Enhancing the Water Splitting Efficiency of Sn-Doped Hematite Nanoflakes by Flame Annealing

摘要

The effect of flame annealing on the water-splitting properties of Sn decorated hematite (a-Fe_2O_3) nanoflakes has been investigated. It is shown that flame annealing can yield a considerable enhancement in the maximum photocurrent under AM 1.5 (100 mWcm~(-2)) conditions compared to classic furnace annealing treatments. Optimizing the annealing time (10 s at 1000 ℃) leads to a photocurrent of 1.1 mAcm~(-2) at 1.23 V (vs. RHE) with a maximum value 1.6 mAcm~(-2) at 1.6 V (vs. RHE) in 1m KOH. The improvement in photocurrent can be attributed to the fast direct heating that maintains the nanoscale morphology, leads to optimized Sn decoration, and minimizes detrimental substrate effects.