High Fenton Catalytic Efficiency from Enhanced Fe 3+ Reduction

Transcription

1 Supporting Information for Fe-N-Graphene Wrapped Al 2 O 3 /Pentlandite from Microalgae: High Fenton Catalytic Efficiency from Enhanced Fe 3+ Reduction Jianqing Ma, Lili Xu, Chensi Shen, Chun Hu,*, Weiping Liu Yuezhong Wen,*, MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou , China College of Environmental Science and Engineering, Donghua University, Shanghai , China Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing , China number of pages: 23 number of figures: 15 number of tables: 2 * Phone: ; fax: address: wenyuezhong@zju.edu.cn (Y.W.) and huchun@rcees.ac.cn (C.H.) S1

2 SUMMARY Total number of pages: 23. (S1-S23) Text S1. Chlorella vulgaris culture conditions. (S4) Text S2. Analytical Methods (S4-S5) Text S3. Calculation of the accumulated turnover numbers (TON). (S5) Text S4. Calculation of the utilization efficiency of H 2 O 2. (S5-S6) Table S1. HPLC detection conditions of different organics. (S7) Table S2. BET surface areas of different catalysts. (S8) Figure S1. Pictures of Chlorella vulgaris and its TEM image. (S9) Figure S2. XRD patterns of Fe N/Pentlandite/Al 2 O 3 /C catalyst. (S10) Figure S3. XPS spectra of Fe N/Pentlandite/Al 2 O 3 /C before reaction and after 12 cycles. (a) Fe ions; (b) Ni ions; (c) Al ions and (d) S. (S11) Figure S4. HAADF-STEM of different catalysts by controlling the addition of metal precursors. (S12) Figure S5. TOC removal of different organics by catalytic degradation and adsorption. (S13) Figure S6. Catalytic degradation of other dyes and refractory organics. Conditions: Initial concentration of dye in (a) 50 mg/l, refractory organics in (b) 30 mg/l, 100 ml, T=25 ºC, catalyst dosage 0.4 g/l, H 2 O 2 40 mm. (S14) Figure S7. (a) ph change (top) and dissolved iron concentrations (bottom) during AR 73 degradation and adsorption by Fe N/Pentlandite/Al 2 O 3 /C (b) AR 73 removal by homogeneous Fenton reaction. (Fe (FeCl 2 4H 2 O) 0.02 mg/l and Ni (NiCl 2 6H 2 O) S2

3 0.35 mg/l. (S15) Figure S8. ph effects on (a) AR 73 removal and H 2 O 2 decomposition; (b) the concentrations of leaching metal. (S16) Figure S9. The reusability of the catalyst. (a) AR 73; (b) phenol. (S17) Figure S10. HAADF-STEM of Fe N/Pentlandite/Al 2 O 3 /C, the catalyst before and after 12 cycles. (a) before reaction; (b) after 12 cycles. (S18) Figure S11. Catalytic degradation and adsorption of AR 73 using catalysts prepared with different metal precursors (Initial AR 73 concentration 50 mg/l, 100 ml, ph 6.8, T=25 ºC, catalyst dosage 0.4 g/l, H 2 O 2 concentration for degradation 40 mm and for adsorption is 0). (S19) Figure S12. Kinetics on the catalytic decomposition of H 2 O 2 (Catalyst dosage 0.4 g/l, H 2 O 2 concentration 40 mm, 100 ml, T=25 ºC). (S20) Figure S13. DMPO spin trapping ESR spectra recorded at ambient temperature for various catalysts with H 2 O 2 in aqueous dispersion for DMPO-HO (a) and in methanol dispersion for DMPO- HO 2 /O 2 - (b): (1) Fe N/Pentlandite/Al 2 O 3 /C; (2) FeNi-C; (3) AlNi-C; (4) FeAl-C; (5) Ni-C; (6) Al-C; (7) Fe-C; (8) CV-C; (9) H 2 O 2. (S21) Figure S14. Cyclic voltammetry in dye solution. (a) Fe-N-Graphene wrapped Al 2 O 3 /Pentlandite; (b) FeNi-C; (c) FeAl-C. (S22) Figure S15. The quenching effects of ethanol and Na 2 CO 3 on the removal of AR 73. The ph was adjusted to 6.8 when Na 2 CO 3 was added. (S23) S3

4 Text S1: Chlorella vulgaris culture conditions C. vulgaris were grown in the SE (Brostol s solution) medium (a common and widely used freshwater medium for green algae) in artificial freshwater at room temperature (25±1.0 ºC) with a light intensity of lux. The C. vulgaris were collected after 12 days. The composition of artificial freshwater (per liter) is as follows: 10.0 g of (NH 4 ) 2 SO 4, 1.5 g of Ca(HPO 4 ) 2, 4.0 g of MgSO 4 7H 2 O, 5.0 g of NaHCO 3, 1.25 g of KCl, 0.25 g of FeCl 3 6H 2 O, 2.86 g of H 3 BO 3, 1.81 g of MnCl 2 4H 2 O, g of ZnCl 2, g of CuCl 2 2H 2 O, g of (NH 4 ) 8 Mo 7 O 24 6H 2 O. Text S2: Analytical Methods The concentrations of phenol, atrazine, bisphenol A (BPA), 2, 4, 5-trichlorophenol (2,4,5-TCP), 4-chlorophenol (4-CP), 4-hydroxyphthalic acid (4-HPA), and 4-methylphthalic acid (4-MPA) were analyzed using a Waters 2695 reverse-phase HPLC with a Waters 2998 photodiode array detector (Milford, MA, USA). Before measurement, 10 μl of tert-butanol as a trapping agent was added to the sample solution (1.0 ml) to stop the degradation of organics. Detailed detection conditions were provided in the following Table S1. Cyclic voltammetry measurements were performed using CHI Electrochemical Station (Model 750b) in a conventional three-electrode electrochemical cell. To avoid any potential contamination of a non-precious metal catalyst by platinum, experiments were carried out using a graphite rod as the counter electrode. An Hg 2 Cl 2 electrode in 3.0 M KCl was used as a reference electrode. All potentials were later converted to the RHE scale. The catalysts were ultrasonically dispersed in an S4

5 alcoholic solution containing suspended Nafion ionomer for one hour to form a catalyst ink, later applied to the glassy-carbon disk surface. The cycling stability tests of the catalysts were performed in the potential range from 0.1 to 0.6 V at room temperature. Text S3: Calculation of the accumulated turnover numbers (TON) The accumulated turnover numbers was measured by three successive ran of the degradation of AR73 and phenol. The initial concentrations of AR 73 and phenol was 3000 mg/l and 3000 mg/l respectively. The catalyst dosage was 0.4 g/l, and the H 2 O 2 was 1M. The solution was in a volume of 100 ml. TON = mol of orgainc converted/ mol of Fe-N (1) The Fe and Ni contents of the Fe-N/Pentlandite/Al 2 O 3 /C measured by the ICP-MS after the acid digestion were mmol/g and mmol/g, respectively. As the Fe in the catalyst contains coordinated Fe (Fe-N sites) and Fe in pentlandite ((Fe, Ni) 9 S 8 ), and the Fe-N sites are viewed as the active sites for the Fenton reactions, thus the equivalent active sites for the catalyst is estimated to mmol/g. Text S4: Calculation of the utilization efficiency of H 2 O 2 The utilization efficiency of H 2 O 2 (η) was calculated using the Luo et al. reported method 1. It is defined as the ratio of the amount of H 2 O 2 used for the degradation ([ H 2 O 2 ] degradation ) with the total amount of the consumed H 2 O 2 ([ H 2 O 2 ] decomposition ), as illustrated in eq.2: η = [ H 2 O 2 ] degradation / [ H 2 O 2 ] decomposition (2) S5

6 The complete mineralization of one mole AR 73 (C 22 H 14 N 4 Na 2 O 7 S 2 ) and phenol (C 6 H 5 OH) will theoretically consume 61 and 14 moles of H 2 O 2, respectively. C 22 H 14 N 4 Na 2 O 7 S H 2 O 2 22CO H 2 O + 4HNO 3 + H 2 SO 4 +Na 2 SO 4 (3) C 6 H 5 OH + 14H 2 O 2 6CO H 2 O (4) By measuring the TOC change in the pollutant solutions, the amounts of the mineralized contaminants were obtained, and thus the value of [ H 2 O 2 ] degradation can be calculated according to eq.3 and eq.4. The value of [ H 2 O 2 ] decomposition was calculated by the change of H 2 O 2 amount in the solution. S6

7 Table S1. Detection conditions of different organics by a Waters e2695 reverse-phase HPLC coupled with a Waters 2998 photodiode array detector (Milford, MA). Organics Column Mobile phase Flow rate (ml/min) Detection wavelength (nm) Temperature ( ) phenol Waters 40% methanol Xbridge TM and 60% water atrazine Phenyl 70 % methanol BPA column and 30% water ,4,5-TCP ( CP mm, 5 μm) HPA Agilent 40% acetonitrile MPA C18 column and 60% ( phosphoric acid mm, 5 μm) solution (0.5%) S7

8 Table S2. BET surface areas of different catalysts samples BET(m 2 /g) Fe-C Al-C Ni-C FeAl-C FeNi-C AlNi-C FeAlNi-C (Fe-N/pentlandite/Al 2 O 3 /C) S8

9 Figure S1. Pictures of Chlorella vulgaris and its TEM image S9

10 Figure S2. XRD patterns of Fe N/Pentlandite/Al 2 O 3 /C catalyst. S10

11 (a) Fe 2p (b) Ni 2p ev ev 2p 3/2 2p 1/2 Intensity (a.u.) ev 2p 1/ ev 2p 3/2 Intensity (a.u.) Fe-N/Pentlandite/Al 2 O 3 /C after reaction Fe-N/Pentlandite/Al 2 O 3 /C Fe-N/Pentlandite/Al 2 O 3 /C Fe-N/Pentlandite/Al 2 O 3 /C after reaction Binding Energy (ev) Binding Energy (ev) (c) Al 2p 74.7 ev (d) S 2p ev SO ev metal sulfide Intensity (a.u.) Intensity (a.u.) Fe-N/Pentlandite/Al 2 O 3 /C Fe-N/Pentlandite/Al 2 O 3 /C after reaction Binding Energy (ev) Fe-N/Pentlandite/Al 2 O 3 /C after reaction Fe-N/Pentlandite/Al 2 O 3 /C Binding Energy (ev) Figure S3. XPS spectra of Fe N/Pentlandite/Al 2 O 3 /C before reaction and after 12 cycles. (a) Fe ions; (b) Ni ions; (c) Al ion and (d) S. S11

12 Figure S4. HAADF-STEM of different catalysts by controlling the addition of metal precursors. S12

13 100 TOC removal efficiency (%) degradation adsorption 0 AR 73 phenolatrzaine BPA 4-CP 2,4,5-TCP 4-HPA 4-MPA Organics Figure S5. TOC removal of different organics by catalytic degradation and adsorption. (Initial concentration of AR mg/l, phenol and other organics 30 mg/l, 100 ml, ph 6.8, T=25 ºC, catalyst dosage 0.4 g/l, H 2 O 2 concentration for degradation 40 mm and for adsorption is 0). S13

14 100 (a) 80 Removal (%) AR1 AB1 Before After AB25 AB40 AB62 AB113 AB193 Dyes RB74 RB194 RR11 RR24 RY2 RY18 Concentration C/C (b) Atrzaine BPA 4-CP 2,4,5-TCP 4-HPA 4-MPA Time (min) Figure S6. Catalytic degradation of other dyes and refractory organics. Conditions: Initial concentration of dye in (a) 50 mg/l, refractory organics in (b) 30 mg/l, 100 ml, T=25 ºC, catalyst dosage 0.4 g/l, H 2 O 2 40 mm. S14

15 ph (a) Degradation Adsorption Leaching Fe (mg/l) Time (min) 1.0 C/C ph=6.8 ph= (b) Time (min) Figure S7. (a) ph change (top) and dissolved iron concentrations (bottom) during AR 73 degradation and adsorption by Fe N/Pentlandite/Al 2 O 3 /C (b) AR 73 removal by homogeneous Fenton reaction. (Fe (FeCl 2 4H 2 O) 0.02 mg/l and Ni (NiCl 2 6H 2 O) 0.35 mg/l. S15

16 100 (a) Removal efficiency (%) Degradation Adsorption H 2 O 2 decomposition 0 3 ph Concentrations (mg/l) (b) Fe Ni Al ph 6.8 Figure S8. ph effects on (a) AR 73 removal and H 2 O 2 decomposition; (b) the concentrations of leaching metal. S16

17 100 (a) Removal (%) AR Cycles 100 (b) Removal (%) Phenol Cycles Figure S9. The reusability of the catalyst. (a) AR 73; (b) phenol. S17

18 (a) (b) Before reaction After 12 cycles Figure S10. HAADF-STEM of Fe-N-graphene wrapped Al 2 O 3 /pentlandite, the catalyst before and after 12 cycles. (a) before reaction; (b) after 12 cycles. S18

19 Degradation Adsorption Removal (%) FeAlNi-CFeAl-C FeNi-C AlNi-C Al-C Ni-C Fe-C Catalysts FeAlNi Figure S11. Catalytic degradation and adsorption of AR 73 using catalysts prepared with different metal precursors (Initial AR 73 concentration 50 mg/l, 100 ml, ph 6.8, T=25 ºC, catalyst dosage 0.4 g/l, H 2 O 2 concentration for degradation 40 mm and for adsorption is 0). S19

20 1.0 H 2 O 2 concentration C/C none 0.6 Fe-C Al-C Ni-C FeAl-C 0.4 FeNi-C AlNi-C-C FeAlNi-C Time (min) Figure S12. Kinetics on the catalytic decomposition of H 2 O 2 (Catalyst dosage 0.4 g/l, H 2 O 2 concentration 40 mm, 100 ml, T=25 ºC). S20

21 5.0E5 (a) Intensity (a.u.) Magnetic Field (mt) Intensity (a.u.) Magnetic Field (mt) Figure S13. DMPO spin trapping ESR spectra recorded at ambient temperature for various catalysts with H 2 O 2 in aqueous dispersion for DMPO-HO (a) and in methanol dispersion for DMPO- HO 2 /O 2 - (b): (1) Fe N/Pentlandite/Al 2 O 3 /C; (2) FeNi-C; (3) AlNi-C; (4) FeAl-C; (5) Ni-C; (6) Al-C; (7) Fe-C; (8) CV-C; (9) H 2 O 2. (b) S21

22 Fe-N-graphene wrapped Al 2 O 3 /pentlandite 100 I/uA (a) E/V (vs.sce) 400 FeNi-C 0 I/uA (b) E/V (vs.sce) FeAl-C 0 I/uA (c) E/V (vs.sce) Figure S14. Cyclic voltammetry in dye solution. (a) Fe-N-Graphene wrapped Al 2 O 3 /Pentlandite; (b) FeNi-C; (c) FeAl-C. S22

23 S23

24 AR 73 concentration (C/C 0 ) without scavenger ethanol Na 2 CO Time (min) Figure S15. The quenching effects of ethanol and Na 2 CO 3 on the removal of AR 73. The ph was adjusted to 6.8 when Na 2 CO 3 was added. Reference 1. Wei, L.; Zhu, L.; Nan, W.; Tang, H.; Cao, M.; She, Y., Efficient Removal of Organic Pollutants with Magnetic Nanoscaled BiFeO 3 as a Reusable Heterogeneous Fenton-Like Catalyst. Environ. Sci. Technol. 2010, 44, (5), S24