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

Abstract

The effect of flame annealing on the water-splitting properties of Sn decorated hematite (α-Fe2O3) nanoflakes has been investigated. It is shown that flame annealing can yield a considerable enhancement in the maximum photocurrent under AM 1.5 (100 mW cm(-2)) conditions compared to classic furnace annealing treatments. Optimizing the annealing time (10 s at 1000 °C) leads to a photocurrent of 1.1 mA cm(-2) at 1.23 V (vs. RHE) with a maximum value 1.6 mA cm(-2) at 1.6 V (vs. RHE) in 1 M 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.

Fabrication of superior α-Fe2O3 nanorod photoanodes through ex-situ Sn-doping for solar water splitting

“…Detailed analysis of the Sn3d peaks for Sn-doped hematite photoanodes shows the presence of two intense peaks at 487 (Sn3d 5/2 ) and 495.4 eV (Sn 3d 3/2 ). These confirm the presence of Sn 4 þ dopants in both in-situ and ex-situ doped samples [22,45].…”

Effect of thermal treatment on solid–solid interface of hematite thin film synthesized by spin-coating deposition solution

“…The charge transport properties of hematite can be improved by doping. Researchers demonstrated to increase the conductivity of hematite by doping it with metal cations with 4 + charge such as Ti [9], Sn [10], Si [11], which improved the photocatalytic properties. Doping with metal cations with 2 + charges has also brought good photoelectrochemical results.…”

Controlled Aqueous Growth of Hematite Nanoplate Arrays Directly on Transparent Conductive Substrates and Their Photoelectrochemical Properties

“…Enormous efforts focusing on tailoring the morphology, impurity doping, and fabricating hematite‐based composites have been made to address these limitations . One potential solution to address the short hole diffusion length associated with bulk α‐Fe 2 O 3 is to use two‐dimensional (2D) nanostructuring for the photoelectrodes . It has been reported that a thickness below 10 nm would ensure a large majority of holes reach the surface to react with water even in the absence of a space‐charge electric field .…”

“…Several approaches such as the thermal annealing of iron foils, plasma‐enhanced chemical vapor deposition (PE‐CVD), and hydrothermal methods have been adopted to fabricate 2D hematite photoelectrodes. For example, hematite nanoflake arrays were fabricated by Wang et al.…”