Supporting Information Robust Co-Catalytic Performance of Nanodiamonds Loaded on WO 3 for the Decomposition of Volatile Organic Compounds under Visible Light Hyoung il Kim, a Hee-na Kim, a Seunghyun Weon, a Gun-hee Moon, a Jae-Hong Kim, b and Wonyong Choi a * a Division of Environmental Science and Engineering/ Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea b Department of Chemical and Environmental Engineering, School of Engineering and Applied Science, Yale University, New Haven, Connecticut 06511, United States *Corresponding author e-mail: wchoi@postech.edu ; fax: +82-54-279-8299 S1
Table S1. Oxygen element in various carbon-based co-catalysts. Samples Oxygen containing surface groups a Oxygen composition b (Atomic %) ND C-OH (Hydroxyl); -O- (Epoxy); C=O (Carbonyl); -COOH (Carboxyl) Ox-ND C-OH (Hydroxyl); -O- (Epoxy); C=O (Carbonyl); -COOH (Carboxyl) 9.27 13.5 H-Ox-ND C-OH (Hydroxyl); -O- (Epoxy) 1.31 G-ND C-OH (Hydroxyl); -O- (Epoxy) 1.08 GO C-OH (Hydroxyl); -O- (Epoxy); C=O (Carbonyl); -COOH (Carboxyl) 30.7 rgo C-OH (Hydroxyl); -O- (Epoxy) 13.8 a Oxygen containing surface groups were estimated from XPS or with FT-IR results in Figures 4, S2, and S12. b Oxygen composition was obtained from XPS analysis. C=O (Carbonyl)/ -COOH (Carboxyl) were assigned at 531.2 ev and C-OH (Hydroxyl)/ -O- (Epoxy) were assigned at 532.4 ev in XPS O 1s. 1,2 References (1) Tao, C. A.; Wang, J. F.; Qin, S. Q.; Lv, Y. A.; Long, Y.; Zhu, H.; Jiang, Z. H. J. Mater. Chem. 2012, 22, 24856-24861. (2) Yang, D.; Velamakanni, A.; Bozoklu, G.; Park, S.; Stoller, M.; Piner, R. D.; Stankovich, S.; Jung, I.; Field, D. A.; Ventrice, C. A.; Ruoff, R. S. Carbon 2009, 47, 145-152. S2
Zeta Potential (mv) 40 20 0-20 WO 3 Bare ND Ox-ND H-Ox-ND G-ND -40 0 2 4 6 8 10 12 ph Figure S1. Zeta (ζ) potential as a function of ph in WO 3, bare ND, Ox-ND, H-Ox-ND, G- ND suspensions (0.1 mm NaNO 3 ). S3
Figure S2. High resolution XPS spectral (c) C 1s and (d) O 1s bands of GO and rgo. FE- SEM images of (c) GO(4 wt%)/wo 3 and (d) rgo(4 wt%)/wo 3. S4
Figure S3. (a, d, g, j, m) HR-TEM images, (b, e, h, k, n) dark-field images, and (c, f, i, l, o) EDS spectra of Ag(1 wt%)/wo 3, Pd(0.1 wt%)/wo 3, Au(1 wt%)/wo 3, Pt(1 wt%)/wo 3, and CuO(2 wt%)/wo 3. S5
Figure S4. High resolution XPS analysis of (a) N-doped TiO 2 (N 1s) and (b) C-doped TiO 2 (C 1s). (c) XRD analysis of Ta 2 O 5, TaON, and Ta 3 N 5. S6
The VOC degradation reaction was conducted in a closed-circulation system to measure concentration of VOC and CO 2 in the glass reactor. The glass reactor had a volume of 300 ml and a quartz window of 3 cm radius. The glass reactor and photoacoustic gas monitor (PA) were connected to Teflon tube (inner radius, 2 mm). Photoacoustic gas monitor can measure the concentration of up to 5 component gases including water vapor simultaneously. All photocatalyst samples were pre-cleaned in clean air under UV irradiation to remove any adsorbed organic impurities Figure S5. (a) Schematic diagram of the experimental setup for the photocatalytic VOCs degradation measurement on NDs/WO 3 films. (b) Spectral irradiance of a halogen lamp (150- W) and the transmittance of a long-pass cut-off filter (420 nm). S7
Figure S6. HR-TEM image of ND(16 wt%)/wo 3. S8
Figure S7. (a) FT-IR spectra of ND, WO 3, and ND(8 wt%)-loaded WO 3. Inset shows the magnified FT-IR spectra of ND, WO 3, and ND (8 wt%)/wo 3 in the range between 1900 and 1400 cm -1. (b) Diffuse reflectance absorption spectra of bare WO 3 and ND(8 wt%)/wo 3. Absorption intensities were expressed in the Kubelka-Munk unit (K.M.= (1-R 2 )/2R). S9
Figure S8. Photocatalytic degradation of acetaldehyde (CH 3 CHO) and the concurrent production of carbon dioxide (CO 2 ) on various visible active photocatalysts (obtained after 1 h reaction). [CH 3 CHO] 0 = 100 ppmv, visible light illumination (λ > 420 nm). TiO 2 (P25) was compared as a representative UV active photocatalyst. CH 3 CHO and CO 2 represent the amount of degraded CH 3 CHO and produced CO 2 after 1 h illumination, respectively. S10
Figure S9. Photocatalytic degradation of (a) acetaldehyde (CH 3 CHO) and (b) production of carbon dioxide (CO 2 ) on Pt-loaded WO 3 as a function of Pt loading (wt%). [CH 3 CHO] 0 = 100 ppm, λ > 420nm. CH 3 CHO and CO 2 represent the amount of degraded CH 3 CHO and produced CO 2 after 1 h illumination, respectively. S11
Figure S10. Time-dependent profiles of (a) photocatalytic degradation of toluene (C 6 H 5 CH 3 ) and (b) the concurrent production of carbon dioxide (CO 2 ) on bare WO 3 and ND(8 wt%)/ WO 3. [C 6 H 5 CH 3 ] 0 = 20 ppmv, λ > 420 nm. S12
Figure S11. Photocatalytic degradation of (a) acetaldehyde (CH 3 CHO) and (b) production of carbon dioxide (CO 2 ) on GO-loaded WO 3 as a function of GO loading (wt%) after 1 h reaction. Time-dependent profiles of (c) photocatalytic degradation of CH 3 CHO and (d) the concurrent production of CO 2 on GO(4 wt%), rgo(4 wt%), and ND(8 wt%) loaded WO 3. [CH 3 CHO] 0 = 100 ppm, under visible light illumination (λ > 420 nm). CH 3 CHO and CO 2 represent the amount of degraded CH 3 CHO and produced CO 2 after 1 h illumination, respectively. Red stars and red triangles in (a) and (b) represent the amount of CH 3 CHO removal and CO 2 production on rgo(4 wt%)/wo 3 (red star) and ND(8 wt%)/wo 3 (red triangle), respectively. S13
Figure S12. Time-dependent profiles of (a) photocatalytic degradation of acetaldehyde (CH 3 CHO) and (b) the concurrent production of carbon dioxide (CO 2 ) on ND, graphitized ND (G-ND), and acid-treated G-ND ((A)G-ND) loaded WO 3 and bare WO 3. All ND-loaded WO 3 samples contained 8 wt% of ND. [CH 3 CHO] 0 = 100 ppm, under visible light illumination (λ > 420nm). (c) HR-TEM image of G-ND. (d) Diffuse reflectance absorption spectra of G-ND(8wt%) loaded WO 3. (e) XPS (O 1s) spectra of bare ND and G-ND. (f) FT- IR spectra of bare ND, G-ND, and G(A)-ND in the range between 4000 and 750 cm -1. Absorption intensities were expressed in the Kubelka-Munk unit (K.M. = (1-R 2 )/2R). S14