title: Core-shell hematite nanorods: a simple method to improve the charge transfer in the photoanode for photoelectrochemical water splitting.
abstract: We report a simple method to produce a stable and repeatable photoanode for water splitting with a core-shell hematite (α-Fe2O3) nanorods system by combining spray pyrolysis and hydrothermal synthesis. Impedance spectroscopy revealed passivation of the surface states by the shell layer, which results in an increase of the charge injection through the hematite conduction band. In pristine hematite more holes are accumulated on the surface and the charge transfer to the electrolyte occurs through surface states, whereas in the core-shell hematite photoanode the majority of hole transfer process occurs through the valence band. As a result the photoactivity of the core-shell nanorods, 1.2 mA cm(-2), at 1.23 V vs RHE, is twice that of pristine hematite nanorods. The alteration of the interface energetics is supported by TEM, showing that the crystallinity of the surface has been improved by the deposition of the shell.
authors: †Solar Fuels Lab, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
authors: Gurudayal
authors: †Solar Fuels Lab, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
authors: Png Mei
authors: PM
authors: Chee
authors: ‡Energy Research Institute@NTU (ERI@N), Research Techno Plaza, X-Frontier Block, Level 5, 50 Nanyang Drive, Singapore 637553.
authors: Pablo P
authors: PP
authors: Boix
authors: †Solar Fuels Lab, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
authors: Hu
authors: H
authors: Ge
authors: †Solar Fuels Lab, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
authors: Fang
authors: F
authors: Yanan
authors: †Solar Fuels Lab, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.|§Applied Science and Technology Department-BioSolar Lab, Politecnico di Torino, Viale T. Michel 5, 15121 Alessandria, Italy.|∥Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom.
authors: James
authors: J
authors: Barber
authors: †Solar Fuels Lab, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
authors: Lydia Helena
authors: LH
authors: Wong
keywords: Mott−Schottky; UV−vis absorption spectra; electrochemical impedance spectroscopy; hematite core−shell nanorods; hole scavenger; incident photon to current conversion efficiency (IPCE); photoelectrochemical water splitting