100083
E-mail: guomin@ustb.edu.cn
FentonX(XRD)(SEM)X(XPS)
/H2O2/” Cu(Mg,Ni)Fe2O4
Ni Cu 1:1(Ni,Mg,Cu)Fe2O4 180 min
10 mg/L B(RhB) 94.5% Cu
(Ni,Mg,Cu)Fe2O4 Fe3+ Cu2+ Fe3+ Cu2+
(·OH) RhB 73.1% 94.5%
(Ni,Mg,Cu)Fe2O4 Fenton
TF803.21 TB34
Fenton-like Catalyst (Ni,Mg,Cu)Fe2O4 from Nickel Sulfide Concentrate
LIU Ya-xian, CHEN Ting, HAN Xing, ZHANG Mei, GUO Min
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Corresponding author, E-mail: guomin@ustb.edu.cn
ABSTRACT Organic contaminants such as dyes and antibiotics have become the focus of research in water treatment in
recent years due to their complex composition, high toxicity and difficulty in biodegradation. Spinel ferrite heterogeneous
Fenton-like catalysts MFe2O4 (MFe2O4, M is a divalent metallic cation or its combination, and the divalent cation is generally
Ni, Zn, Mn, Co, Cu, Mg, etc.) have attracted much attention because of their excellent structural stability and good magnetic
recovery performance. However, the catalytic activity of these catalysts is not ideal and almost all the reported catalysts are
1:2020-00-00 :(U1810205)

synthesized by pure chemical reagents, which restrict their industrial application. Therefore, the preparation of highly
efficient heterogeneous Fenton-like catalysts with low cost becomes the key to the treatment of refractory organic
wastewater. In this study, copper doped spinel ferrite (Ni,Mg,Cu)Fe2O4 was successfully synthesized from nickel sulfide
concentrate by a coprecipitation-calcination method. The effect of copper doping amount on the structure, micro-morphology
and catalytic performance of as-prepared samples was systematically investigated by means of X-ray diffraction, scanning
electron microscopy and X-ray photoelectron spectroscopy. The optimal catalytic system was established as the photo-
assisted Fenton-like catalytic system “(Ni,Mg,Cu)Fe2O4 catalyst/H2O2/visible light”, and the enhancement mechanism of
copper doping on the catalytic activity of (Mg,Ni)Fe2O4 was revealed. Results showed that all formed products were pure
spinel ferrites under the selected preparing conditions. When the molar ratio of Ni to Cu was 1:1, the formed
(Ni,Mg,Cu)Fe2O4 catalyst achieved 94.5% degradation efficiency for 10 mg/L RhB solution under the condition of visible
light irradiation for 180 min. This case may be mainly ascribed to that the relative contents of Fe3+ and Cu2+ ions at octahedral
site increased, namely, the amount of Fe3+ and Cu2+ exposed on the surface of ferrite increased with copper doping, as well as
the synergetic effect between them, accelerated the reaction of hydroxyl radical (·OH), thus improved the degradation
efficiency of RhB solution from 73.1% to 94.5%.
KEY WORDS nickel sulfide concentrate; copper doping amount; spinel ferrite (Ni,Mg,Cu)Fe2O4; heterogeneous Fenton-
like catalyst; calcination
2/3 90%[1-2]


H2O CO2
pH2.53.5
Fenton Fe2+
pH[6-8] Fenton
MFe2O4M
NiZnMnCoMg
Wang [9] Fe3O460 min
B RhB 90% Roonasi [10]
Fe3O4ZnFe 2O4MnFe2O4 CuFe2O4
CuFe2O4 175 min 78%Wang[11]-
MnFe2O4180 min 90.6%
Fe3+ Fe2+ Fe3+/Fe2+
Fenton
Fe3O4A Fe3O4
Sharma[13]-MFe2O4M=CuZnNi
Co CuFe2O4Huang [14] Cu2+

Fe2.88Cu0.12O4 Fenton B
Cu2+ H2O2 ·OH Cu+ Fe3+ Fe2+ Cu2+/Cu+=0.166
VFe3+/Fe2+=0.770 V Fe2+
Jacobs[15]
Fenton·OH
CuFe2O4Cu2+

[16]
Fenton


90 ºC 24 h 20075 μm
X X-ray FluorescenceXRF X X-ray
diffractionXRD XRD
1 1 FeSiSNiCuMgAlO
(Fe,Ni)9S8FeS2CuFeS2
SiO2
1 X
Table 1 Chemical compositions of nickel sulfide concentrate analyzed by XRF
Components Fe S Si Ni Mg Cu Al Ca Co
Weight Content / (%) 14.06 12.12 7.88 6.28 6.25 1.37 1.14 1.09 0.16
Components K Ti Na Cr Zn Mn Pb Cl O and others
Weight Content / (%) 0.11 0.08 0.10 0.07 0.08 0.04 0.03 0.02 49.12
1 XRD
FeCl3•6H2ONaOHH2O2
HClCuCl2·2H2OBC28HClN2O3

1.2
1.2.1
[19]FeCl30.8 molL-1HCl
0.75 moll-120:1 mLg-190 ºC7 h12.5 g
500 mL90 ºC
250 mLFeCl3HCl
Inductively coupled plasma atomic emission spectrometerICP-OES
2FeNiMgCu
(Ni,Mg,Cu)Fe2O4
2 ICP-OES
Table 2 The main metal elements in the leaching solution of nickel sulfide concentrate by ICP-OES analysis
Metal element Fe Ni Mg Cu Co Al Ca Ti K Cr Zn Mn
concentration / (gL-1) 40.84 3.305 0.965 0.698 0.023 0.210 0.275 0.005 0.016 0.009 0.009 0.007
concentration / (molL-1) 0.729 0.056 0.040 0.011 0.001 0.008 0.007 <0.001 <0.001 <0.001 <0.001 <0.001
1.2.2 (Ni,Mg,Cu)Fe2O4
MFe2O4 Fe3+ 2 Fe
Ni+Cu+Mg 2 FeNi+Cu+Mg
6.76 2 Fe pH
Fe3+ Fe(OH)3 FeNi+Cu+Co 2
CuCl2·2H2O Cu
Ni Cu 1:0.6MNi:Cu=1:0.6MNi:Cu=1:1
Cu

2 15 mL Fe2+
Fe3+ 5 molL-1NaOH pH 2.40
NaOH 5000 rmin-1 5 min
3 0.180 g 0.353 g CuCl2·2H2O
MNi:Cu=1:0.6MNi:Cu=1:1 CuCl2·2H2O
5 molL-1NaOH pH 12.0 NaOH
5000 rmin-1 5 min
4 3-5
1000 ºC 2 h
(Ni,Mg,Cu)Fe2O4
(Ni,Mg,Cu)Fe2O4 Fenton RhB
200 mL 10 mgL-1 RhB 250 mL
0.20 g 30 min-
1.0% H2O2
10 cm 30 min 5 mL1:1 V/V
·OH 5000 r·min-1 5 min 2 mL
-TU-1901 RhB1 RhB
Fenton
0 0= 1 / 100% = 1 / 100% (1)t tη A A C C
η RhB%A0At t 554 nm RhB
AbsC0Ct t RhBmgL-1
1.3
2500Rigaku(Ni,Mg,Cu)Fe2O4
Image JXX-
ray FluorescenceXRFXRF-1800(Ni,Mg,Cu)Fe2O4
XX-ray photoelectron spectroscopyXPSAXIS U1tra
DLDKratos(Ni,Mg,Cu)Fe2O4
absorption spectraUV-VisAL-104RhB
F-7000FL2-
425 nm315 nm
2(A) Cu

(110)(220)(311)(222)(400)(422)(511)(440)
(311) 2(B) Cu2θ
a Cu
2[20] 3 Cu
a 0.4285 nm 0.4289 nm Cu2+
Ni2+Mg2+Cu2+ B
Cu2+ 0.073 nm Ni2+Mg2+ 0.069 nm 0.072 nm
Cu2+
θ aλX1.50562θXRD
2θ(hkl)XRD(hkl)(311)
2 CuXRD(A)(311) 2θ(B). a:
; b: MNi:Cu=1:0.6; c: MNi:Cu=1:1
Fig.2 XRD patterns of Cu-doped samples (A) and Enlarged views of 2θ angle shift corresponding to the strongest peaks
of the (311) crystal planes. (a: undoped; b: MNi:Cu=1:0.6; c: MNi:Cu=1:1)
3 Cu(Ni,Mg,Cu)Fe2O4
Table 3 Chemical formula and unit cell parameters of (Ni,Mg,Cu)Fe2O4 with different Cu contents
MNi:Cu (molar ratio) Chemical formula a / nm
undoped Ni0.63Mg0.30Cu0.07Fe2O4 0.4285
1:0.6 Ni0.48Mg0.21Cu0.31Fe2O4 0.4287
1:1 Ni0.24Mg0.15Cu0.61Fe2O4 0.4289
Ni0.63Mg0.30Cu0.07Fe2O4Ni0.48Mg0.21Cu0.31Fe2O4Ni0.24Mg0.15Cu0.61Fe2O4 Cu
Cu2+[21]
Cu
Ni0.24Mg0.15Cu0.61Fe2O4 CuNi0.24Mg0.15Cu0.61Fe2O4


3 Cu SEM(A)(D): ; (B)(E): MNi:Cu=1:0.6; (C)(F):
MNi:Cu=1:1
Fig.3 SEM images and particle size distributions of Cu-doped samples ((A) and (D): undoped; (B) and (E): MNi:Cu=1:0.6; (C)
and (F): MNi:Cu=1:1)
Cu
238±75 nm271±87 nm 217±47 nm 3(D-
F)MNi:Cu=1:1
Cu XPS 4(A)
Cu FeNiMgCuO 4(B) Cu
Fe 2pFe 2p3/2~710.6~713.3 eV Fe3+
FeOct 3+ Fe3+FeTet
3+Fe 2p1/2~725.0 eV Fe3+
[24] 4(C)Mg 2pMg 2p~48.9~49.6 eV
Mg2+MgOct 2+Mg2+MgTet
2+[24] 4(D)Ni 2pNi
2p3/2~854.8 ~856.5 eV Ni2+NiOct 2+ Ni2+
NiTet 2+~861.6 eVNi2+[25] 4(E) Cu 2p
~934.1eV~935.5 eV Cu 2p3/2 B Cu2+CuOct 2+ A
Cu2+CuTet 2+ Cu 2p3/2~941.7 eV Cu2+[26]
XPS XRDXRF
(Ni,Mg,Cu)Fe2O4

4 CuXPS(A)(B) Fe 2p; (C) Mg 2p; (D) Ni 2p; (E) Cu 2p. (a): ;
(b): MNi:Cu=1:0.6; (c): MNi:Cu=1:1
Fig.4 Full XPS spectra of copper-doped ferrites (A) and high resolution XPS spectra of (B) Fe 2p; (C) Mg 2p; (D) Ni 2p; (E)
Cu 2p. (a: undoped; b: MNi:Cu=1:0.6; c: MNi:Cu=1:1)
2.2
5(A) RhB10 mgL-1
“+” 180 min RhB 1.7%
Fenton“+H2O2” 180 min RhB
10.7% H2O2
0.20 g 1.0 % H2O2
Fenton“/H2O2/”RhB 73.1%
Fenton RhB RhB
“(Ni,Mg,Cu)Fe2O4/H2O2/”
·OH 5(B) 2-
120 minPL

·OH Fenton“(Ni,Mg,Cu)Fe2O4
/H2O2/”·OH RhB
(B)
Fig.5 The degradation curves of RhB solutions in different catalytic reaction systems (A) and Fluorescence spectra of 2-
hydroxyterephthalic acid produced by the catalytic system of Ni0.63Mg0.30Cu0.07Fe2O4/H2O2/vis capturing ·OH radicals
2.3 CuRhB
CuFentonRhB
10 mg/LCuRhB6Cu
MNi:Cu = 1:1RhB30-180 min
MNi:Cu = 1:0.6Cu
·OH
6 Cu RhB(A) ; (B) MNi:Cu=1:0.6; (C) MNi:Cu=1:1
Fig.6 Absorbance curves of RhB solution degraded by catalysts with different Cu doping (A) undoped; (B) MNi:Cu=1:0.6; (C)
MNi:Cu=1:1
η 7(A) CuRhB180 min
Cu RhB 73.1% CuMNi:Cu=1:06 1:1
RhB 88.8% 94.5% Cu
RhB RhB
3[21]kappmin-1 7(B) Cu
MNi:Cu=1:1 RhB kapp 0.01424 min-1
7(A)

0 appIn / = (3)tC C k t
C0 RhB(mgL-1)Ct t RhB(mgL-1)kapp
(min-1)
7 Cu RhB(A)(B)
Fig.7 RhB degradation by samples with different Cu doping amounts (A) and kinetic characteristics (B)
2.4 Cu(Ni,Mg,Cu)Fe2O4
Fenton“(Ni,Mg,Cu)Fe2O4/H2O2” RhB
4-6[27-29]
3+ 2+ + -3 -1 -1 2 2 2Fe +H O Fe + +H 2.00 10 (OH M s 4)=k
2+ 3+ - -1 -1 2 2Fe +H O Fe + +OH 76 OH = M s (5)k
2 2RhB CO +H O degradation products OH+ (6)
XPS 4 Fe3+
Fe3+≡Fe3+ H2O2 Fe2+≡Fe2+ HO2·
4≡Fe2+H2O2·OH5·OH RhB
CO2H2O6 Fenton
45≡Fe3+ H2O2≡Fe2+
·OH
≡Fe3+/≡Fe2+ RhB 10.7% 5
≡Fe3+≡Fe2+H2O2·OH Fenton

(Ni,Mg,Cu)Fe2O4(eCB -)(Ni,Mg,Cu)Fe2O4(hVB
+)
7 eCB - Fe3+≡Fe2+8≡Cu2+
≡Cu+9≡Cu+≡Fe3+≡Fe2+10[30-32]
≡Fe3+≡Fe2+ Fenton
H2O2·OH≡Cu+ H2O2·OH11
RhB eCB - H2O2·OH
12 hVB +H2O·OH13 RhB
“(Ni,Mg,Cu)Fe2O4/H2O2/”
8

- 2 4 2 4 CB VB (Ni,Mg,Cu)Fe O (Ni, (7)Mg,Cu)Fe O ( h )
hv
e
2+ - 2
3+ + 2+2+Fe + (1Fe + Cu Cu 0)
+ 2+ - 2 2Cu +H O Cu + OH+OH (11)
- 2 4 CB 2 2 OH OH (Ni,Mg ,Cu)Fe O ( ) H (12)Oe
+ 2 4 VB 2 OH H (Ni,M g,Cu)Fe O ( h ) H (O 13)
8 “(Ni,Mg,Cu)Fe2O4/H2O2/”
Fig.8 Reaction mechanism diagram of catalytic system “(Ni,Mg,Cu)Fe2O4 catalyst/H2O2/visible light”
Cu XPS

H2O2·OH RhB
4(B-E) Cu Fe 2pMg 2pNi 2p Cu 2pXPS
CuFeOct 3+ 72.4%
84.6%CuOct 2+ 32% 65.5%MgOct
2+ 53.6%
48.0%NiOct 2+ 77.1% 67.3% CuMg2+Ni2+
Cu2+Ni2+Mg2+
9

9 Cu
Fig.9 The percentages of metal ion octahedral positions in ferrites with different copper doping amounts
XPS“(Ni,Mg,Cu)Fe2O4/H2O2/” Cu
(Ni,Mg,Cu)Fe2O4 Fe3+ Cu2+ Fenton
·OH Cu2+/Cu+Eθ(Cu2+/
Cu+)=0.166 V Fe3+/Fe2+Eθ(Fe3+/Fe2+)=0.770 V≡Cu2+ Fenton
≡Cu+≡Fe3+≡Fe2+ Cu2+
Fe3+·OHRhB
73.1% 94.5% 7
3
(Ni,Mg,Cu)Fe2O4 Fenton Cu
(2) “(Ni,Mg,Cu)Fe2O4/H2O2/” RhB
25 ºC 1.00 gL-1 H2O2 1.0 % 180 mWcm-2
MNi:Cu=1:1 10 mgL-1 RhB 94.5%
(3) Cu CuOct 2+ FeOct
3+MgOct 2+
NiOct 2+ Cu2+ Fe3+
(Ni,Mg,Cu)Fe2O4/H2O2/·OH Cu


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Fenton(Ni,Mg,Cu)Fe2O4