Interfacial band-edge engineered TiO2 protection layer on Cu2O photocathodes for efficient water reduction reaction

Jaesuk Choi, Jun Tae Song, Ho Seong Jang, Min Jae Choi, Dong Min Sim, Soonmin Yim, Hunhee Lim, Yeon Sik Jung, Jihun Oh

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


Photoelectrochemical (PEC) water splitting has emerged as a potential pathway to produce sustainable and renewable chemical fuels. Here, we present a highly active Cu2O/TiO2 photocathode for H2 production by enhancing the interfacial band-edge energetics of the TiO2 layer, which is realized by controlling the fixed charge density of the TiO2 protection layer. The band-edge engineered Cu2O/TiO2 (where TiO2 was grown at 80 °C via atomic layer deposition) enhances the photocurrent density up to −2.04 mA/cm2 at 0 V vs. RHE under 1 sun illumination, corresponding to about a 1,200% enhancement compared to the photocurrent density of the photocathode protected with TiO2 grown at 150 °C. Moreover, band-edge engineering of the TiO2 protection layer prevents electron accumulation at the TiO2 layer and enhances both the Faraday efficiency and the stability for hydrogen production during the PEC water reduction reaction. This facile control over the TiO2/electrolyte interface will also provide new insight for designing highly efficient and stable protection layers for various other photoelectrodes such as Si, InP, and GaAs. [Figure not available: see fulltext.]

Original languageEnglish
Pages (from-to)57-65
Number of pages9
JournalElectronic Materials Letters
Issue number1
Publication statusPublished - Jan 1 2017
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials

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