Readme file for dataset relating to paper Nano-structured rhodium doped SrTiO3 – visible light activated photocatalyst for water decontamination All file names in the data set refer to sample names in paper Dataset contains text/ascii data files for powder Xray diffraction, Xray photoelectron spectroscopy, Xray absorption near edge spectroscopy, Uv/vis spectroscopy including photocatalytic methyl orange degradation, cell counts for photocatalytic antimicrobial studies (as an Excel spreadsheet), thermogravimetric analysis and infrared spectroscopy Sample preparation: Nanostructured SrTiO3 particles can be synthesized hydrothermally at temperatures between 100 – 200 °C by reacting nanoparticulate TiO2 particles with alkaline solution (pH > 12) of Sr(OH)2.[1-3] After the synthetic reaction washing the slurry with organic acid (formic acid, acetic acid) removes the residual SrCO3.[2] The hydrothermal synthesis reaction route can further enhance any photocatalytic reaction rate due to the increased surface area.[1, 3] SrTi1-xRhxO3 (x = 0; 0.01; 0.025; 0.050; 0.075; 0.1) were prepared hydrothermally by the replacement of Ti4+ ions at the B-site of the perovskite structure. The starting materials, Aeroxide® TiO2 P25 (Sigma Aldrich, 99.5 %), Sr(OH)2 · 8 H2O (Sigma Aldrich, 95 %), and RhCl3 · xH2O (Sigma Aldrich, Rh 38-40 %) were mixed in 60 mL of distilled water at room temperature, using 2 % excess of Sr(OH)2·8 H2O. The hydrothermal reaction was carried out in a 125 mL Teflon-coated reactor, placed in an oven at 180 °C for 12 h, 5 °C/min heating rate, 2 °C/min cooling rate. The synthesized oxides were washed twice with 1 M acetic acid and then twice with distilled water. The suspension was dried at 60 °C in air. The yield of the product was 1.2 g, 44 % when 7.5 mmol of starting materials were used. To ensure any residual amount of SrCO3 was successfully removed from the samples by acetic acid washing FTIR measurement was carried out. Following the hydrothermal synthesis using the same batch of the suspension half of the sample was washed twice with 1 M acetic acid and then twice with distilled water (AA) and the other half of the slurry was only washed 2 times with distilled water (DW). The FTIR measurement indicates the presence of CO32- in DW sample and also confirmed that after treating the sample with 1 M acetic acid the SrCO3 content was completely removed (1468 cm-1 assigned peak)[4] (Figure S1). Only the purified materials were used in this study. The parent phase is white and the Rh-doped compounds show the colour of yellow to brownish-yellow depending on the dopant concentration. FTIR spectra were recorded on powder samples using a Bruker Tensor 27 Spectrometer. Sample characterisation: Xray Diffraction: Powder X-ray diffraction (PXRD) was carried out on the powders using a Philips Panalytical X’Pert diffractometer with Co Ka1 of ? = 0.178901 nm. The samples were analyzed by 'Xpert Highscore Plus software and Pawley fitted using Topas Academic (Version 5). Thermogravimetric Analysis: TGA was performed on a TA Instruments Q600 under air atmosphere between room temperature and 800 ºC with a ramp rate of 1.00ºC/min Xray photoelectron spectroscopy: The composition and valence state of Rh in the samples were analysed by X-ray Photoelectron Spectroscopy (XPS) using PSP Hemispherical Electron Analyser with a Mg Ka (1253.6 eV) DUEL anode X-ray source and using PSP vacuum chamber (1*10-10 bar, 16 hrs sample collection, room temperature). For XPS data analysis CasaXPS software was used. A Shirley type background was applied and the peaks were fitted with 70% Lorentzian and 30% Gaussian function line shapes. Area ratios were constrained for each element according to the j values, for example for Rh 3d spectra j will be 3/2 and 5/2. The area ratio for the two spin orbit peaks 3d3/2 : 3d5/2 was given as 2 : 3. For Ti 2p spectra, 2p1/2 : 2p3/2 was correspondent to the area of 1 : 2. For O 1s subshell the j value is ½ therefore no area constraints needed. Equal FWHM was adjusted for all spin orbit peaks. The charge shift was adjusted to give the Ti 2p3/2 core level peak at 458.5 eV which is assigned to the Ti4+ state of and SrTiO3.The binding energies for the Rh 3d5/2 peaks were referenced to standard materials, Rh0 (rhodium foil, GoodFellow) measured at 307.4 eV and Rh3+ (Rh2O3, Sigma Aldrich) measured at 308.4 eV. Xray absorption near edge spectroscopy: X-ray absorption near-edge spectroscopy (XANES) measurements were undertaken on beamline B18 at the Diamond Light Source, Harwell, UK. The Diamond Light Source operated at 3.0 GeV and with a ring current of 300 mA. The station was equipped with a Si[311] double crystal monochromator and a 36-element Ge fluorescence detector. Approximately 20 mg of each sample was mixed with 100 mg of cellulose and pressed into a 13 mm pellet. Measurements were performed in fluorescence mode. Internal energy calibration was achieved by simultaneously measuring the XANES spectrum from a metallic rhodium foil and assigning the zero point in the second derivative to 23,219.9 eV. Six scans were collected from each sample. These were summed, calibrated and background subtracted using the Athena program. Data analysis was performed using the Athena software Uv-vis spectroscopy: UV/Vis diffuse reflectance spectroscopy (DRS) and absorption measurements were taken on Shimadzu UV-2550 UV/Vis spectrometer, equipped with a Labsphere integrating sphere over the spectral range 300-1400 nm, using BaSO4 reflectance standards. Photocatalytic dye (methyl orange) degradation: The photocatalytic degradation of MO (Methyl-Orange) dye solution was carried out under visible light irradiation by using a 300 W Xe lamp with 420 nm cut-off filter. The reaction suspensions were prepared by adding the catalyst (0.1 g) to 100 mL of 0.02 g/L MO solution. The as-made suspension was purged with air during the whole reaction. The suspension was stirred in the dark for overnight to ensure adsorption/desorption equilibrium of the dye has been attained on the surface of the catalyst prior to irradiation. During irradiation, 4 mL of the suspension was removed at 15 minute intervals for subsequent MO concentration analysis following filtering by a 0.2 µm syringe filter. The absorption spectra of the aliquots were recorded in the range of 240 - 720 nm to determine the rate of MO degradation. The pH of the MO solution remained constant throughout the time reaction during the decomposition process (pH 7.2-7.7), no further adjustment was needed. Microbiology: Microbiological studies were carried out as follows. A series of stock suspensions (0 % w/V, 0.01 % w/V, 0.05 % w/V, 0.1 % w/V) were made by dispersing 0 g, 0.003 g, 0.015 g, 0.03 g SrTi0.95Rh0.05O3 photocatalysts in 30 mL aq. PBS (Phosphate Buffered Saline) solution. The suspensions were kept in dark covered with aluminium foil and stirred for overnight with magnetic stirrer bars in order to get a fine suspension of the catalyst. Bacterial overnight cultures were set up by transferring a single bacterial colony from a streak plate to 10 mL Luria-Bertani (LB) broth for E. coli (strain MC1061)[8] and incubated at 37 oC overnight with shaking at 200 rpm. The overnight bacterial cultures were then sub-cultured and 250 µL was transferred to 10 mL fresh LB broth. The subculture was incubated at 37 oC until they reached mid-log growth phase (O.D.600= ~0.4-0.5), when the sub-cultures (5 ?L) were transferred to 5 mL of pre-autoclaved photocatalyst suspensions in aq. PBS. Four types of suspensions containing the catalyst as well as the E. coli sub-culture were made: light (L), dark (D), control light (CL), control dark (CD). The L experiment is described as follows: 5 µL of E. coli sub-cultures were transferred to 5 mL PBS containing 0.1 % w/V sterilised photocatalyst and exposed to a visible light source (? > 420 nm). The suspension of the D experiment was prepared identically, but during the photo-disinfection reaction, kept in dark by covering with aluminium foil. The CL and CD suspensions contained no added photocatalyst, only E. coli, and were exposed to either visible light (CL) or were kept in dark (CD). Toxicity samples were prepared in duplicate with biological replicates (Figure S12); time course experiments were plated with biological replicates and repeated three times (Figure S13). During the reaction, the cells in the photocatalyst suspensions were stirred with magnetic stirrer bars. 100 µL samples were taken at 0 min, 120 min, 240 min and 360 min and diluted in 900 µL aq. PBS in a dilution series from 100 to 10-5. In order to make up the cell dilutions in PBS and also to make the dilution series representative for plating, the harvested samples were vortexed and 20 µL of each dilution was spot plated in duplicate on LB agar plates and incubated overnight at 37 oC.[9] The bacterial colonies were then counted and colony forming units (CFU) mL 1 were calculated. The average and standard deviation of viable cell populations as colony forming units per mL (CFU mL-1) of the duplicated biological replicates were plotted over time.