Plasmon Au modified 3D-nanostructrue CoOx decorated hematite for highly efficient photoelectrochemical water splitting

Abstract

Surface modification and interface engineering are efficient strategies to address the serious charge recombination and the sluggish water oxidation kinetics in photoelectrochemical water splitting. In this work, CoOx decorated hematite nanosheets (Fe2O3/CoOx) are deposited on Nickel foam by the in-situ hydrothermal process. Au nanoparticles are incorporated on Fe2O3/CoOx semiconductors (Fe2O3/CoOx/Au) by electrochemical deposition. In photoelectrochemical test, Fe2O3/CoOx attains a photocurrent density of 1.87 mA cm−2 at 1.23 VRHE, which is 4.45 times that for α-Fe2O3. The onset potential of Fe2O3/CoOx decreases by 266 mV compared with α-Fe2O3. The 3D-nanostructrue Fe2O3/CoOx/Au attains a photocurrent density of 3.88 mA·cm−2 at 1.23 VRHE, which is 9.24 times that of ɑ-Fe2O3. The applied bias photon-to-current efficiency, charge separation and charge injection efficiency of Fe2O3/CoOx/Au are improved. EIS studies show the co-modification of CoOx and Au reduces charge transfer resistance. This strategy would provide a potential approach to promote light absorption and charge separation for photoelectrochemical catalyst.