S1

Supporting Information for

Fe-N-Graphene Wrapped Al2O3/Pentlandite from Microalgae:

High Fenton Catalytic Efficiency from Enhanced Fe3+ 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 310058,

China

‡College of Environmental Science and Engineering, Donghua University, Shanghai

201620, China

§Key Laboratory of Drinking Water Science and Technology, Research Center for

Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China

number of pages: 23

number of figures: 15

number of tables: 2

* Phone: +86 571 8898 2421; fax: +86 571 8898 2421.

E-mail address: wenyuezhong@zju.edu.cn (Y.W.) and huchun@rcees.ac.cn (C.H.)

S2

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 H2O2. (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/Al2O3/C catalyst. (S10)

Figure S3. XPS spectra of Fe−N/Pentlandite/Al2O3/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, H2O2 40 mM. (S14)

Figure S7. (a) pH change (top) and dissolved iron concentrations (bottom) during AR

73 degradation and adsorption by Fe−N/Pentlandite/Al2O3/C (b) AR 73 removal by

homogeneous Fenton reaction. (Fe (FeCl2· 4H2O) 0.02 mg/L and Ni (NiCl2·6H2O)

S3

0.35 mg/L. (S15)

Figure S8. pH effects on (a) AR 73 removal and H2O2 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/Al2O3/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, H2O2 concentration for degradation 40 mM and for

adsorption is 0). (S19)

Figure S12. Kinetics on the catalytic decomposition of H2O2 (Catalyst dosage 0.4 g/L,

H2O2 concentration 40 mM, 100 mL, T=25 ºC). (S20)

Figure S13. DMPO spin trapping ESR spectra recorded at ambient temperature for

various catalysts with H2O2 in aqueous dispersion for DMPO-HO• (a) and in

methanol dispersion for DMPO- HO2•/O2

•- (b): (1) Fe−N/Pentlandite/Al2O3/C; (2)

FeNi-C; (3) AlNi-C; (4) FeAl-C; (5) Ni-C; (6) Al-C; (7) Fe-C; (8) CV-C; (9) H2O2.

(S21)

Figure S14. Cyclic voltammetry in dye solution. (a) Fe-N-Graphene wrapped

Al2O3/Pentlandite; (b) FeNi-C; (c) FeAl-C. (S22)

Figure S15. The quenching effects of ethanol and Na2CO3 on the removal of AR 73.

The pH was adjusted to 6.8 when Na2CO3 was added. (S23)

S4

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 4500-5000 lux. The C. vulgaris were collected

after 12 days. The composition of artificial freshwater (per liter) is as follows: 10.0 g

of (NH4)2SO4, 1.5 g of Ca(HPO4)2, 4.0 g of MgSO4·7H2O, 5.0 g of NaHCO3, 1.25 g

of KCl, 0.25 g of FeCl3·6H2O, 2.86 g of H3BO3, 1.81 g of MnCl2·4H2O, 0.1045 g of

ZnCl2, 0.0602 g of CuCl2·2H2O, 0.039 g of (NH4)8Mo7O24·6H2O.

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 Hg2Cl2

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

S5

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

H2O2 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/Al2O3/C measured by the ICP-MS

after the acid digestion were 0.250 mmol/g and 0.168 mmol/g, respectively. As the Fe

in the catalyst contains coordinated Fe (Fe-N sites) and Fe in pentlandite ((Fe, Ni)9S8 ),

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 0.082 mmol/g.

Text S4: Calculation of the utilization efficiency of H2O2

The utilization efficiency of H2O2 (η) was calculated using the Luo et al. reported

method1. It is defined as the ratio of the amount of H2O2 used for the degradation

([∆H2O2]degradation) with the total amount of the consumed H2O2 ([∆H2O2]decomposition),

as illustrated in eq.2:

η = [∆H2O2]degradation / [∆H2O2]decomposition (2)

S6

The complete mineralization of one mole AR 73 (C22H14N4Na2O7S2) and phenol

(C6H5OH) will theoretically consume 61 and 14 moles of H2O2, respectively.

C22H14N4Na2O7S2 + 61H2O2 → 22CO2 + 65H2O + 4HNO3 + H2SO4 +Na2SO4 （3）

C6H5OH + 14H2O2 → 6CO2 + 17H2O (4)

By measuring the TOC change in the pollutant solutions, the amounts of the

mineralized contaminants were obtained, and thus the value of [∆H2O2]degradation can

be calculated according to eq.3 and eq.4. The value of [∆H2O2]decomposition was

calculated by the change of H2O2 amount in the solution.

S7

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®

XbridgeTM

Phenyl

column

(250 × 4.6

mm, 5 μm)

40% methanol

and 60% water

1.0 210 25

atrazine 70 % methanol

and 30% water

0.8 222 25

BPA 0.8 224 25

2,4,5-TCP 1.0 295 25

4-CP 0.8 280 25

4-HPA Agilent®

C18 column

(250 × 4.6

mm, 5 μm)

40% acetonitrile

and 60%

phosphoric acid

solution (0.5%)

0.2 210 45

4-MPA

S8

Table S2. BET surface areas of different catalysts

samples BET(m2/g）

Fe-C 336.056

Al-C 145.238

Ni-C 44.689

FeAl-C 332.412

FeNi-C 54.341

AlNi-C 28.346

FeAlNi-C (Fe-N/pentlandite/Al2O3/C) 119.268

S9

Figure S1. Pictures of Chlorella vulgaris and its TEM image

S10

Figure S2. XRD patterns of Fe−N/Pentlandite/Al2O3/C catalyst.

S11

735 730 725 720 715 710 705

711.7 eV 2p3/22p1/2724.9 eV

Fe 2p

Inte

nsity

(a.u

.)

Binding Energy (eV)

Fe-N/Pentlandite/Al2O3/C after reaction Fe-N/Pentlandite/Al2O3/C

(a)

885 880 875 870 865 860 855 850 845

856.3 eV874.1 eV 2p3/2

2p1/2

Inte

nsity

(a.u

.)

Binding Energy (eV)

Fe-N/Pentlandite/Al2O3/C Fe-N/Pentlandite/Al2O3/C after reaction

Ni 2p(b)

82 80 78 76 74 72 70 68 66

Inte

nsity

(a.u

.)

Binding Energy (eV)

Fe-N/Pentlandite/Al2O3/C Fe-N/Pentlandite/Al2O3/C after reaction

Al 2p(c) 74.7 eV

175 170 165 160

163.5 eV metal sulfide

←

Binding Energy (eV)

Inte

nsity

(a.u

.)

Fe-N/Pentlandite/Al2O3/C after reaction Fe-N/Pentlandite/Al2O3/C

←

(d) S 2p 168.8 eV SO2-4

Figure S3. XPS spectra of Fe−N/Pentlandite/Al2O3/C before reaction and after 12

cycles. (a) Fe ions; (b) Ni ions; (c) Al ion and (d) S.

S12

Figure S4. HAADF-STEM of different catalysts by controlling the addition of

metal precursors.

S13

AR 73 phenol

Atrzaine BPA 4-CP2,4,5-TCP 4-HPA 4-MPA

0

20

40

60

80

100

TO

C r

emov

al e

ffici

ency

(%)

Organics

degradation adsorption

Figure S5. TOC removal of different organics by catalytic degradation and

adsorption. (Initial concentration of AR 73 50 mg/L, phenol and other organics

30 mg/L , 100 mL, pH 6.8, T=25 ºC, catalyst dosage 0.4 g/L, H2O2 concentration

for degradation 40 mM and for adsorption is 0).

S14

0

20

40

60

80

100

After

AB193AB113 RY18RY2

RR24RR11

RB194RB74AB62

AB40AB25AB1

Rem

oval

(%)

DyesAR1

Before

(a)

0 10 20 30 40 50 600.0

0.2

0.4

0.6

0.8

1.0

Conc

entr

atio

n C/

C 0

Time (min)

Atrzaine BPA 4-CP 2,4,5-TCP 4-HPA 4-MPA

(b)

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, H2O2 40 mM.

S15

4

5

6

7

8

0 5 10 15 20 25 300.00

0.01

0.02

0.03

pH

Degradation Adsorption

(a)

Lea

chin

g Fe

(m

g/L

)

Time (min)

0 5 10 15 20 25 300.0

0.2

0.4

0.6

0.8

1.0

C/C

0

Time (min)

pH=6.8 pH=4.4

(b)

Figure S7. (a) pH change (top) and dissolved iron concentrations (bottom) during

AR 73 degradation and adsorption by Fe−N/Pentlandite/Al2O3/C (b) AR 73

removal by homogeneous Fenton reaction. (Fe (FeCl2· 4H2O) 0.02 mg/L and Ni

(NiCl2·6H2O) 0.35 mg/L.

S16

0

20

40

60

80

100 (a)

6.853

pH

Rem

oval

eff

icie

ncy

(%)

Degradation Adsorption H2O2 decomposition

0.0

0.2

0.4

0.6

0.8

6.85

Con

cent

ratio

ns (m

g/L

)

pH

Fe Ni Al

3

(b)

Figure S8. pH effects on (a) AR 73 removal and H2O2 decomposition; (b) the

concentrations of leaching metal.

S17

1 2 3 4 5 6 7 8 9 10 11 120

20

40

60

80

100

Cycles

Rem

oval

(%)

(a)

AR73

1 2 3 4 5 6 7 8 9 10 11 120

20

40

60

80

100

Cycles

Rem

oval

(%)

Phenol

(b)

Figure S9. The reusability of the catalyst. (a) AR 73; (b) phenol.

S18

Before reaction After 12 cycles

Figure S10. HAADF-STEM of Fe-N-graphene wrapped Al2O3/pentlandite, the

catalyst before and after 12 cycles. (a) before reaction; (b) after 12 cycles.

(a) (b)

S19

FeAlNi-CFeAl-C FeNi-C AlNi-C Al-C Ni-C Fe-C0

20

40

60

80

100

Rem

oval

(%)

Catalysts

Degradation Adsorption

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, H2O2 concentration for

degradation 40 mM and for adsorption is 0).

S20

0 5 10 15 20 25 300.2

0.4

0.6

0.8

1.0

H2O

2 co

ncen

trat

ion

C/C 0

Time (min)

none Fe-C Al-C Ni-C FeAl-C FeNi-C AlNi-C-C FeAlNi-C

Figure S12. Kinetics on the catalytic decomposition of H2O2 (Catalyst dosage 0.4

g/L, H2O2 concentration 40 mM, 100 mL, T=25 ºC).

S21

3460 3480 3500 3520 3540 3560

In

tens

ity (a

.u.)

Magnetic Field (mT)

98765432

1

5.0E

5

(a)

3460 3480 3500 3520 3540 3560

9

87

654321

Inte

nsity

(a.u

.)

Magnetic Field (mT)

(b)

Figure S13. DMPO spin trapping ESR spectra recorded at ambient temperature

for various catalysts with H2O2 in aqueous dispersion for DMPO-HO• (a) and

in methanol dispersion for DMPO- HO2•/O2

•- (b): (1) Fe−N/Pentlandite/Al2O3/C;

(2) FeNi-C; (3) AlNi-C; (4) FeAl-C; (5) Ni-C; (6) Al-C; (7) Fe-C; (8) CV-C; (9)

H2O2.

S22

0.1 0.2 0.3 0.4 0.5 0.6

-200

-100

0

100

200

300

I/uA

E/V (vs.SCE)

Fe-N-graphene wrapped Al2O3/pentlandite

(a)

0.1 0.2 0.3 0.4 0.5 0.6-1200

-800

-400

0

400

(b)

I/uA

E/V (vs.SCE)

FeNi-C

0.1 0.2 0.3 0.4 0.5 0.6-300

-200

-100

0

100

200

(c)

I/uA

E/V (vs.SCE)

FeAl-C

Figure S14. Cyclic voltammetry in dye solution. (a) Fe-N-Graphene wrapped

Al2O3/Pentlandite; (b) FeNi-C; (c) FeAl-C.

S23

S24

0 5 10 15 20 25 300.0

0.2

0.4

0.6

0.8

1.0

AR 7

3 co

ncen

trat

ion

(C/C

0)

Time (min)

without scavenger ethanol Na2CO3

Figure S15. The quenching effects of ethanol and Na2CO3 on the removal of AR

73. The pH was adjusted to 6.8 when Na2CO3 was added.

Reference

1. Wei, L.; Zhu, L.; Nan, W.; Tang, H.; Cao, M.; She, Y., Efficient Removal of

Organic Pollutants with Magnetic Nanoscaled BiFeO3 as a Reusable Heterogeneous

Fenton-Like Catalyst. Environ. Sci. Technol. 2010, 44, (5), 1786.