Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics. This journal is © the Owner Societies 2014
Supporting Information Mn-modified Bi2Ti2O7 Photocatalysts: A Bandgap Engineered Multifunctional Photocatalysts for Hydrogen Generation Satyajit Gupta, Luis De Leon, Vaidyanathan (Ravi) Subramanian* * Department of Chemical and Materials Engineering, University of Nevada, Reno, NV 89557, USA. E-mail:
[email protected]; Fax: +1 775-327-5059; Tel: +1 775-784-4686.
Cooling water inlet
Cooling water outlet Collection of gas produced by downward displacement of water and quantification by GC
Sealed glass vessel
High pressure Hg lamp
Argon purging to remove dissolved gases
Hg Lamp information Medium pressure immersion type, quartz mercury vapor lamp. The energy output of the light source is summarized below: Wavelength range (nm) 220-280 (Far UV) 280-320 (Middle UV) 320-400 (Near UV) 400-800 (Visible) 800-1400 (Infrared) Total:
Energy output (Watt) 27 28.7 28 75.7 16.4 175.8
Energy output (%) 15.4 16.3 15.9 43.1 9.3 100
Fig. S1 The schematic and photograph of a slurry reactor assembly along with the light source used for the photocatalytic generation of hydrogen.
Fig. S2 A measure of the cumulative H2 yield obtained using the slurry reactor in the presence of various methanol concentrations. The X-axis indicates various water/methanol ratios starting with plain water in the left and moving towards plain methanol to the right .
Intensity, a.u.
BTO
Reused MnBTO1
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30
40
50
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70
2 theta, degree
Fig. S3 XRD of the MnBTO1 catalyst is shown after it is used in a 2nd run. It is compared with BTO catalyst to indicate that there is no compositional change detected in the sample.
1 µm
Fig. S4 SEM image of the 1 wt% Mn (Mn_BTO1) photocatalyst after reuse in the 2nd run in the presence of a fresh methanol – water mixture (50/250-V/V). The reaction was carried out for 6 h hours.
% Transmittance
Mn_BTO1 Cycle 1 Cycle 2
-C=O
Due to adsorbed -OMe and polymerized formaldehyde
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3500
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Wavenumber (cm-1) Fig. S5 FTIR of the Mn_BTO1 photocatalyst before and after using it in repeat runs with fresh methanol water mixtures.