Supporting Information Metal-Organic Framework Templated Catalysts: Dual Sensitization of PdO-ZnO Composite on Hollow SnO 2 Nanotubes for Selective Acetone Sensors Won-Tae Koo, Ji-Soo Jang, Seon-Jin Choi,, Hee-Jin Cho, and Il-Doo Kim, * Department of Materials Science and Engineering and Applied Science Research Institute, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea *Corresponding author e-mail: idkim@kaist.ac.kr S-1
Table of Contents - Figure S1. SEM images of ZIF-8 and Pd@ZIF-8, and STEM image of Pd@ZIF-8 - Figure S2. XRD analysis and N 2 adsorption/desorption isotherms of ZIF-8 and Pd@ZIF-8 - Figure S3. SEM image of as-spun PVP/Sn precursor NFs, SnO 2 NFs, and SnO 2 NTs - Figure S4. TEM image of PdO@ZnO particles and PdO@ZnO-SnO 2 NTs - Figure S5. SEM image of 3.41 wt% and 0.204 wt% of PdO@ZnO loaded SnO 2 NTs - Figure S6. STEM and EDS analysis of PdO@ZnO-SnO 2 NTs - Figure S7. XRD analysis of SnO 2 NFs, SnO 2 NTs, and PdO@ZnO-SnO 2 NTs - Figure S8. XPS analysis of PdO@ZnO-SnO 2 NTs - Figure S9. SEM image of PdO@ZnO-SnO 2 NFs - Figure S10. Supplementary sensing characteristics - Figure S11. Exhaled breath sampling - Figure S12. N 2 uptake analysis of PdO@ZnO-SnO 2 NFs and PdO@ZnO-SnO 2 NTs - Figure S13. UPS analysis of Pd@ZnO powders - Figure S14. Band structure of PdO@ZnO/SnO 2 - Table S1. Acetone sensing properties of SMO based sensors - References S-2
Figure S1. SEM image of (a) ZIF-8, (b) Pd@ZIF-8, and (c) STEM image of Pd@ZIF-8. S-3
Figure S2. (a) Powder XRD analysis of ZIF-8 and Pd@ZIF-8, (b) N 2 adsorption/desorption analysis of ZIF-8 and Pd@ZIF-8. S-4
Figure S3. SEM image of (a) as-spun PVP/Sn NFs, (b) SnO2 NFs, and (c,d) SnO2 NTs. S-5
Figure S4. TEM images of (a,b) PdO@ZnO particles achieved by the calcination of Pd@ZIF-8 at 600 C and (c) PdO@ZnO-SnO 2 NTs. S-6
Figure S5. SEM images of; (a,b) 3.41 wt% of and (c,d) 0.204 wt% of PdO@ZnO loaded SnO 2 NTs. S-7
Figure S6. (a) STEM images, (b) EDS elemental mapping images, and (c) EDS elemental line profiles of PdO@ZnO-SnO 2 NTs. S-8
Intensity (a.u.) PdO@ZnO-SnO 2 NTs SnO 2 NTs SnO 2 NFs JCPDS # 41-1445 20 30 40 50 60 70 2θ (degree) Figure S7. XRD analysis of SnO 2 NFs, SnO 2 NTs, and PdO@ZnO-SnO 2 NTs. S-9
Figure S8. XPS analysis using high resolution spectrum of PdO@ZnO-SnO 2 NTs in the vicinity of (a) Sn 3d, (b) O 1s, (c) Zn 2p, and (d) Pd 3d. S-10
Figure S9. SEM images of PdO@ZnO-SnO 2 NFs. S-11
Figure S10. (a) Sensing characteristics to 5 ppm of acetone in the temperature range of 300 450 C, (b) Linear apporoximation of the detction limit of PdO@ZnO-SnO 2 NTs, and (c) Cyclic sensing response of PdO@ZnO-SnO 2 NTs toward 1 ppm of acetone at 400 C. S-12
Figure S11. (a) Exhaled breath sampling in a tedlar bag, and (b) Exhaled breath sample and a diagram pump. S-13
Figure S12. N 2 adsorption/desorption isotherms of (a) PdO@ZnO-SnO 2 NFs and (b) PdO@ZnO-SnO 2 NTs. S-14
Figure S13. (a) UPS spectrum of PdO@ZnO powders, (b) high binding energy region, and (c) low binding energy region. S-15
Figure S14. Band structure of PdO@ZnO and SnO 2 at equllibrium. S-16
Table S1. Recent publications on chemiresistive sensors for detecting acetone at highly humid ambient. Gas species Materials Optimal Relative Response/ Detection Response temperature humidity Recovery time limit Ref. Hollow SnO 2 6.7 at 38 s/ 260 C Dry nanobelt 5 ppm 9 s 5 ppm 1 RGO-SnO 2 10.0 at 28 s/ 350 C 95% RH NFs 5 ppm 100 s 1 ppm 2 Pt-WO 3 4.11 at 300 C 85% RH hemitube 2 ppm / 120 ppb 3 Acetone 7.12 at 30 s/ Pt-SnO 2 NFs 400 C 80% RH 120 ppb 4 3 ppm 20 s Rh 2 O 3 WO 3 11.2 at 7.09 s/ 350 C 95% RH 100 ppb 5 NFs 1 ppm 225.29 s Pt-SnO 2 NTs 350 C 90% RH 25 at 40 s/ 1 ppm 60 s 20 ppb 6 Pt-PS_SnO 2 34.8 at 350 C 90% RH NTs 1 ppm / 10 ppb 7 PdO@ZnO- 5.06 at 16 s/ 400 C 90% RH SnO 2 NTs 1 ppm 36 s 10 ppb this work S-17
References (1) Li, W. Q.; Ma, S. Y.; Luo, J.; Mao, Y.; Cheng, Z. L.; Gengzang, D. J.; Xu, X. L.; Yan, S. H. Synthesis of Hollow SnO 2 Nanobelts and Their Application in Acetone Sensor. Mater. Lett. 2014, 132, 338-341. (2) Choi, S. J.; Jang, B. H.; Lee, S. J.; Min, B. K.; Rothschild, A.; Kim, I. D. Selective Detection of Acetone and Hydrogen Sulfide for the Diagnosis of Diabetes and Halitosis Using SnO 2 Nanofibers Functionalized with Reduced Graphene Oxide Nanosheets. ACS Appl. Mater. Interfaces 2014, 6, 2588-2597. (3) Choi, S. J.; Lee, I.; Jang, B. H.; Youn, D. Y.; Ryu, W. H.; Park, C. O.; Kim, I. D. Selective Diagnosis of Diabetes Using Pt-Functionalized WO 3 Hemitube Networks As a Sensing Layer of Acetone in Exhaled Breath. Anal. Chem. 2013, 85, 1792-1796. (4) Shin, J.; Choi, S. J.; Lee, I.; Youn, D. Y.; Park, C. O.; Lee, J. H.; Tuller, H. L.; Kim, I. D. Thin- Wall Assembled SnO 2 Fibers Functionalized by Catalytic Pt Nanoparticles and their Superior Exhaled-Breath-Sensing Properties for the Diagnosis of Diabetes. Adv. Funct. Mater. 2013, 23, 2357-2367. (5) Kim, N. H.; Choi, S. J.; Kim, S. J.; Cho, H. J.; Jang, J.S.; Koo, W.T.; Kim, M. I.; Kim, I. D. Highly Sensitive and Selective Acetone Sensing Performance of WO 3 Nanofibers Functionalized by Rh 2 O 3 Nanoparticles. Sens. Actuators B 2016, 224, 185-192. (6) Jang, J. S.; Kim, S. J.; Choi, S. J.; Kim, N. H.; Meggie, H.; Rothschild, A.; Kim, I. D. Thin- Walled SnO 2 Nanotubes Functionalized with Pt and Au Catalysts via the Protein Templating Route and Their Selective Detection of Acetone and Hydrogen Sulfide Molecules. Nanoscale 2015, 7, 16417-16426. (7) Jang, J. S.; Choi, S. J.; Kim, S. J.; Hakim, M.; Kim, I. D. Rational Design of Highly Porous SnO 2 Nanotubes Functionalized with Biomimetic Nanocatalysts for Direct Observation of Simulated Diabetes. Adv. Funct. Mater. 2016, 26, 4740-4748. S-18