Rapid Flame-Annealed CuFe2O4 as Efficient Photocathode for Photoelectrochemical Hydrogen Production

• DOI: 10.1021/acssuschemeng.8b05824
• Publication Date: 2019-02-06T19:03:31Z
• Authors: Sangwook Park; Ji Hyun Baek; Liang Zhang; Jae Myeong Lee; Kevin H. Stone; In Sun Cho; Jinghua Guo; Hyun Suk Jung; Xiaolin Zheng
• Keywords: Photocathode; Photocurrent; Photoconductivity

Copper ferrite (CuFe2O4) possesses an indirect bandgap in the range of 1.54–1.95 eV. It is used as attractive p-type photocathode photoelectrochemical (PEC) water splitting, and theoretically it can yield a maximum photocurrent density ∼27 mA/cm2 solar-to-hydrogen conversion efficiency ∼33%. To date, only few reports have been published on CuFe2O4 photocathodes with very low-photocurrent densities, value 0.4 at V vs RHE. Herein, we prepared FTO glass sol–gel method followed by either high-temperature flame annealing or furnace annealing. We found that flame-annealed generated 1.82 RHE approximately 3.5 times higher than furnace-annealed (0.52 mA/cm2). This also those all reported photocathodes, any Cu containing ternary oxide (Cu–M–O, M: Fe, Bi, V, Nb) (0.1–1.3 RHE). An improved PEC performance elicited owing to beneficial effects physical, optical, electrical properties CuFe2O4. Flame enhances light absorption property slightly reducing bandgap, forming thicker film increased porosity. reduces oxygen vacancy concentration CuFe2O4, thus facilitating charge transport interfacial transfer processes. Moreover, requires 16 min, which much shorter time required for (∼9 h). These results demonstrate rapid effective means fabricating metal photoelectrodes enhanced splitting performance.