This dataset includes a range of experimental data collected. In particular, raw data from X-Ray diffraction patterns (XRD), UV- Vis spectroscopy, X-Ray Photoelectron Spectroscopy (XPS), linear sweep voltammetries, photcurrent times curves, IPCE and electrochemical impedance spectroscopy (EIS). Specifics of the methology employed for data collection is described in detail in the experimental part of the paper. Raw data has been labeled following the same methodology as in the paper.Physical Characterisation
X- ray diffraction (XRD) patterns were collected from 10 to 60° (2θ) using a Bruker D8 diffractometer with Cu Kα (0.154 nm) radiation.
Raman spectroscopy was performed on a Renishaw inVia system using a 532 nm diode-pumped solid-state laser (DPSS) manufactured by Cobolt. A 50x long distance objective was used to focus the laser beam onto the sample.
UV-Vis measurements were carried out in a Lambda 950 spectrometer (Perkin Elmer) with an integrating sphere (150 mm InGaAS). The samples were mounted in the center. Diffuse-reflectance UV-Vis measurements were performed in an Agilent Cary 100 spectrophotometer.
X-ray photoelectron spectroscopy (XPS) was performed with a monochromatic Al Kα X-ray-source (1486.74 eV, Specs Focus 500 monochromator). C 1s was used for internal charge correction. Ultraviolet photoelectron spectroscopy (UPS) was carried out with a He I source (E = 21.218 eV) in the same chamber. A hemispherical analyzer (Specs Phoibos 100) was used for both XPS and UPS measurements. The base pressure of the system was ∼10−9 mbar.
(Photo)electrochemical characterisation:
Photoelectrochemical (PEC) performance of photoanodes was measured under simulated solar light using a WACOM Super Solar Simulator (Model WXS-505-5H, AM 1.5, Class AAA) and an EG&G Princeton Applied Research Potentiostat/Galvanostat (Model 273A). PEC cells were prepared using a three electrode configuration with Pt as the counter electrode, a silver chloride reference electrode (Ag/AgCl-reference electrode, XR300, Radiometer Analytical, EAg/AgCl=0.197 VRHE) and the as-prepared photoanodes as the working electrode. Illumination was directed towards the back of the photoanode (Glass-FTO-sample). 1 M NaOH (pH=13.6) was used as electrolyte.
Incident photon-to-current efficiency (IPCE) measurements were performed using an Xe lamp (LOT, LSH302), an Acton Research monochromator (Spectra Pro 2155) and an electronic shutter (Uniblitz LS6). The intensity of the monochromated light was measured by a calibrated photodiode (PD300R-UV, Ophir) just after a clean FTO-glass substrate placed at the working electrode position, in the absence of PEC cell quartz window or PEC cell electrolyte.
PEC impedance spectroscopy (PEIS) was carried out under simulated sunlight (AM 1.5G, 100 mW cm-2) using a CompactStat. Potentiostat (Ivium technologies). Measurements were performed in a frequency range from 105 to 0.1 Hz, with an AC voltage amplitude of 10 mV at a potential range of 0.6 to 1.2 VRHE with 0.05V steps, in 1M NaOH. EIS measurements in the dark were also measured to obtain Mott-Schottky plots. These measurements were performed at a fixed frequency of 100 and 1000 Hz.Data for the different technqiues are presented in different documents. Data has been labeled as follows: #_Fe2TiO5, #_Fe2TiO5_Zn, #_Fe2O3 and #_Fe2O3_Zn, where # corresponds to the nomenclature of x and y axis of the plot
