Versatile inorganic organic hybrid WO x ethylenediamine nanowires: Synthesis, mechanism and application in heavy metal ion adsorption and catalysis

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1 Electronic Supplementary Material Versatile inorganic organic hybrid WO x ethylenediamine nanowires: Synthesis, mechanism and application in heavy metal ion adsorption and catalysis Wei Li 1,2, Fang Xia 2, Jin Qu 1, Ping Li 1, Dehong Chen 3, Zhe Chen 1, Yu Yu 1, Yu Lu 2, Rachel A. Caruso 2,3 ( ), and Weiguo Song 1 ( ) 1 Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, , China 2 CSIRO Materials Science and Engineering, Private Bag 33, Clayton South, Victoria, 3169, Australia 3 PFPC, School of Chemistry, The University of Melbourne, Melbourne, Victoria, 3010, Australia Supporting information to DOI /s Table S1 Removal of Pb 2+ from water: A comparison of adsorption by WO x EDA nanowires with precipitation by an equivalent amount of ethylenediamine a Pb 2+ solutions Adding WO x EDA nanowires Adding ethylenediamine C 0 (mg L 1 ) Initial ph Volume (ml) Mass (mg) ph C e (mg L 1 ) b q e (mg g 1 ) b Mass (mg) ph C e (mg L 1 ) b a The equivalent mass of ethylenediamine is calculated using the weight percentage (20.7 wt.%) of ethylenediamine within the hybrid WO x EDA nanowires. b C e represents the equilibrium concentration of Pb (mg L 1 ) and q e is the mass of Pb 2+ ions adsorbed per unit weight of the adsorbent at equilibrium (mg g 1 ). Address correspondence to Weiguo Song, wsong@iccas.ac.cn; Rachel A. Caruso, rcaruso@unimelb.edu.au

2 Figure S1 (a) HRTEM image of a WO x EDA nanowire; (b) SAED pattern of many interwoven WO x EDA hybrid nanowires; (c) SAED pattern of interwoven WO x EDA hybrid nanowires after electron beam irradiation for 20 s. Figure S2 (a) Typical EDX spectrum of WO x EDA hybrid nanowires; (b) PXRD (λ = Å) pattern of WO x EDA hybrid nanowires; (c) nitrogen adsorption desorption isotherm of WO x EDA hybrid nanowires.

3 Figure S3 (a) FTIR spectrum of the hybrid WO x EDA nanowires; (b) Raman spectrum of the WO x EDA nanowires. Figure S4 (a) The full XPS survey; (b) W 4f XPS peaks; (c) N 1s XPS peak of hybrid WO x EDA nanowires. Figure S5 (a) TGA curve of as-synthesized WO x EDA hybrid nanowires; (b) PXRD (λ = Å) pattern of the product after calcination of WO x EDA hybrid nanowires in air at 550 C for 3 h. Nano Research

4 Nano Res. Figure S6 (a) and (b) SEM images of the sample after calcination of hybrid WOx EDA nanowires at 550 C for 3 h; (c) TEM image of an individual as-obtained WO3 nanorod; (d) HRTEM image of the as-obtained WO3 nanorod. Figure S7 SEM images of products derived from various tungsten salt precursors: (a) and (d) using WO3; (b) and (e) using silicotungstic acid; (c) and (f) using WCl6.

5 Nano Res. Figure S8 PXRD (λ = Å) patterns of products derived from commercial WO3, silicotungstic acid and ammonium tungstate. Figure S9 (a) Crystal structure of monoclinic WO3; (b) crystal structure of tetragonal WO3. Figure S10 SEM image of WOx EDA nanowires as obtained from the in situ SR-XRD experiment. Nano Research

6 Figure S11 Time-resolved in situ SR-XRD patterns (λ = Å) during the transformation from the ammonium tungstate precursor to WO x EDA hybrid nanowires. (a) and (b) continuous evolution of in situ SR-XRD patterns of products upon the reaction: (a) is the top view of three dimensional pattern of (b); (c) selected SR-XRD patterns of the starting ammonium tungstate and in situ resulting products formed at several different reaction times. Note that the SR-XRD pattern of the starting ammonium tungstate was collected before mixing with ethylenediamine and the ammonium tungstate phase transformed to an unknown intermediate (SR-XRD pattern at 0 min) instantly upon mixing with ethylenediamine at room temperature. Figure S12 PXRD patterns (λ = Å) of products in the batch solvothermal synthesis after 1 h using ammonium tungstate or monoclinic WO 3 as precursor. After 1 h in the batch synthesis (60 ml of EDA), all the ammonium tungstate was transformed to WO x EDA product, whereas monoclinic WO 3 still remained unchanged.

7 Nano Res. Figure S13 SEM images of products using different diamines: (a) 1,3-propanediamine; (b) 1,6-hexamethylenediamine; (c) diethylenetriamine; (d) triethylenetetramine. Figure S14 (a) and (b) SEM images of WOx EDA nanowires after adsorption of 1000 ppm of Pb2+ and (c) EDX spectrum of WOx EDA hybrid nanowires after adsorption of 1000 ppm of Pb Nano Research

8 Rather than adsorption, precipitation of Pb 2+ ions forms small particles of polyhedral lead oxide/hydroxide [S1]. Figure S15 (a) and (b) Raman spectra of WO x EDA nanowires before and after adsorption of Pb 2+ ; (c) PXRD (λ = Å) patterns of WO x EDA hybrid nanowires before and after adsorption of Pb 2+. Figure S16 (a) TEM image of WO 3 nanosheets after treatment with dilute HNO 3 ; (b) HRTEM image of a WO 3 nanosheet showing a lattice spacing of nm, corresponding to the (200) plane of tetragonal WO 3. Figure S17 Adsorption isotherms of Pb 2+, Cd 2+ and Cu 2+ on the calcined monoclinic WO 3 nanorods at room temperature.

9 Figure S18 (a) Adsorption isotherm of As(V) over the WO x EDA hybrid nanowires at room temperature; (b) magnified section ranging from 0 to 200 mg L 1 as marked in (a), in which the adsorption data are well fitted with the Langmuir adsorption isotherm (R 2 = 0.987). This result suggests that the adsorption behavior could correspond to the Langmuir model at low concentrations, whereas arsenate anions may be removed through a different route at higher concentrations, similar to previously reported studies [S2, S3]. Reference [S1] Wiberg, N.; Holleman, A. F.; Wiberg, E. Inorganic Chemistry; Academic Press: New York, [S2] Li, W.; Cao, C. Y.; Wu, L. Y.; Ge, M. F.; Song, W. G. Superb fluoride and arsenic removal performance of highly ordered mesoporous aluminas. J. Hazard. Mater. 2011, 198, [S3] Manos, M. J.; Petkov, V. G.; Kanatzidis, M. G. H 2x Mn x Sn 3 x S 6 (x = ): A novel reusable sorbent for highly specific mercury capture under extreme ph conditions. Adv. Funct. Mater. 2009, 19, Nano Research