Inverse opal structured α-Fe2O3 on graphene thin films: Enhanced photo-assisted water splitting

Kan Zhang, Xinjian Shi, Jung Kyu Kim, Jae Sung Lee, Jong Hyeok Park

Research output: Contribution to journalArticle

55 Citations (Scopus)

Abstract

A graphene interlayer was successfully inserted into inverse opaline hematite (α-Fe2O3) photoanodes for solar water splitting using the template assisted electrodeposition method. Finding the optimal thermal annealing temperature is crucial for the successful attainment of the inverse opaline hematite nanostructure on a graphene thin film. This is because an appropriate temperature is required to convert pre-deposited Fe 0 into hematite with optimum crystalline structure and to simultaneously remove the soft polystyrene template without thermal degradation of the graphene film on a transparent conductive substrate. Different from the conventional strategies based on graphene-semiconductor systems, this novel mechanism has been proposed whereby the graphene interlayer can act as both an electron transfer layer and an electrolyte blocking barrier, by which it not only reduces the charge recombination at the substrate-electrolyte interface but also helps electron transportation from α-Fe2O3 to the substrate of the photoanode. Therefore, both photocurrent density and incident photon-to-current efficiency (IPCE) have been remarkably improved, which are several times higher than those of the pure inverse opaline hematite photoanode.

Original languageEnglish
Pages (from-to)1939-1944
Number of pages6
JournalNanoscale
Volume5
Issue number5
DOIs
Publication statusPublished - 2013 Mar 7

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All Science Journal Classification (ASJC) codes

  • Materials Science(all)

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