Enhanced Photoelectrochemical Water Splitting Efficiency of a Hematite–Ordered Sb:SnO₂ Host–Guest System

Abstract

Host-guest systems such as hematite/SnO2 have attracted a great deal of interest as photoanodes for photoelectrochemical water splitting. In the present work we form an ordered porous tin oxide layer formed by self-organizing anodization of Sn films on a FTO substrate. Subsequently the anodic tin oxide nanostructure is doped with antimony (ATO) by a simple impregnation and annealing treatment, and then decorated with hematite using anodic deposition. Photoelectrochemical water splitting experiments show that compared to conventional SnO2 nanostructures, using a Sb doped nanochannel SnO2 as a host leads to a drastic increase of the water splitting photocurrent response up to 1.5 mA cm(-2) at 1.6 V (vs. RHE) in 1 M KOH under AM 1.5 (100 mW cm(-2) ) conditions compared to 0.04 mA cm(-2) for the non-Sb doped SnO2 scaffold.

Activation of Ultrathin Films of Hematite for Photoelectrochemical Water Splitting via H2 Treatment

“…[5][6][7][8] However,n anostructuring and dopingh ave been pervasivei nt he a-Fe 2 O 3 literature,a st he rapid recombination of photoexcited charge carriers within pure a-Fe 2 O 3 (as ar esult of as hort excited-state lifetimea nd an anometer-scale charge diffusion length) resultsinl ow overall photocurrents. [9][10][11][12][13][14] Most recently,o xygen vacancies were found to dramatically increasep hotocurrents within semiconductor photoanodes for water oxidation. [15][16][17][18][19] These intrinsic dopants create mixedvalent metal oxidesi namanner similart ot hat of extrinsic dopants, that is, by increasingt he number of available charge carriers,w hich therebyi mproves charge transport and decreases the rate of recombination.…”

Achieving Highly Efficient Photoelectrochemical Water Oxidation with a TiCl4 Treated 3D Antimony‐Doped SnO2 Macropore/Branched α‐Fe2O3 Nanorod Heterojunction Photoanode

“…Recently, NTO nanoparticle,10 1D ATO nanorod array,11 and 3D photonic FTO nanocone array[[qv: 9g]] have been successfully used as transparent conductive host for loading the hematite nanoparticle or nanoplate guest which exhibit exciting PEC performances. Given that the 1D hematite nanorod owns an enhanced conductivity along [110] axis,[[qv: 2b]] it is predictable that incorporating 1D hematite nanorod with TCOs will lead to an eminent performance.…”

On the improvement of PEC activity of hematite thin films deposited by high-power pulsed magnetron sputtering method

“…nanotubes) and the so-called host scaffold-guest absorber structures recently applied for PEC water splitting reactions. Such organizations provide a significant enhancement of the absorbed photon to current efficiency (APCE) due to a high surface area [22,23] simultaneously suppressing recombination of the holes in bulk.…”