SUPPORTING INFORMATION

Self-Assembled 3D hierarchical MnCO3/NiFe layered

double hydroxides as a superior electrocatalysts for the

oxygen evolution reactions

Rajmohan Rajendirana, Nallal Muthuchamyb, Kang Hyun Parkb, Oi Lun Lic*, Hee-Je Kima,

Kandasamy Prabakara*

aDepartment of Electrical Engineering, Pusan National University, 2 Busandaehak-ro

63beon-gil, Geumjeong-gu, Busan-46241, Republic of Korea.

bDepartment of Chemistry, Pusan National University, 2 Busandaehak-ro 63beon-gil,

Geumjeong-gu, Busan-46241, Republic of Korea.

c School of Materials Science and Engineering, Pusan National University, 2 Busandaehak-

ro 63beon-gil, Geumjeong-gu, Busan-46241, Republic of Korea

Figure S1 XPS survey of Ni-FeLDH, Ni-MnCO3, and Ni-FeLDH@MnCO3.

Figure S2 (a) Polarization curves and (b) Tafel plot for all samples and standard Ir/C before iR-correction.

Figure S3. LSV curve normalized by mass loading and bar graph of mass activity of Ni-FeLDH, Ni-MnCO3 and Ni-FeLDH@MnCO3 at 1.58 V vs. RHE.

Figure S4 Cyclic voltammograms in the region of 0.05 – 0.15 V for Ni-FeLDH, Ni-MnCO3, and Ni-FeLDH@MnCO3

Figure S5. OER plot Ni-FeLDH@MnCO3 powder coated glassy carbon disk and Pt ring electrode in RRDE setup

Table S1 EIS analysis of Ni-FeLDH@MnCO3 at various potential vs. RHE in 1M KOH

Potential V

vs RHE

Rs Rct Cdl (F s(a-1)) Rads Cads (F s(a-1))

1.52 0.685 2.337 0.042 0.170 0.173

1.54 0.683 1.017 0.016 0.133 0.188

1.56 0.684 0.562 0.035 0.156 0.163

1.58 0.687 0.381 0.028 0.139 0.165

1.60 0.689 0.298 0.015 0.108 0.185

1.62 0.691 0.249 0.017 0.081 0.181

1.64 0.686 0.134 0.017 0.162 0.111

Table S2: Comparison of various earth abundant metal based electrocatalysts

CatalystOver-

potential (mV)

Geometrical

Electrode area (cm2)

J (mA cm-2)

Tafel slope (mV decade-1)

Electrode Electrolyte Method Ref

Ni-FeLDH@MnC

O3

275 1 10 45 Ni foam 1 M KOH Hydrothermal

This work

Ni-FeLDH@MnC

O3

309 1 50 45 Ni foam 1 M KOH Hydrothermal

This work

Ni-FeLDH@MnC

O3

328 1 100 45 Ni foam 1 M KOH Hydrothermal

This work

Pa-NiFe LDH NS/NIF 326 2 100 157 Ni foam 1 M KOH Hydrothe

rmal [1]

NiFe-LDH/NiCo2O4

350 - 50 53 Ni foam 1 M KOH Hydrothermal [2]

Ni2.5Co0.5Fe LDH/NF 275 2 10 99 Ni foam 0.1 M

KOH

Electrode depositio

n[3]

CQD/NiFe-LDH 305 0.94 10 35

Powder coated on

Glassy carbon

1 M KOH Hydrothermal [4]

NiCo-LDH 430 - 50 40 Carbon paper

0.1 M KOH

Hydrothermal

continuous flow

synthesis

[5]

MCNTs@ (Ni,Co)3Si2O5(

OH)4440 0.94 10 96 Glassy

carbon0.1 M KOH

solvothermal [6]

MnFe2O4/NiCo2O4

334 1.57 10 46 Glassy carbon

0.1 M KOH

Thermal decompo

sition[7]

NiCo-NiCoO2@NC 318 0.94 10 76 Glassy

carbon 1 M KOH Hydrothermal [8]

CoFe-LDH 360 - 50 92 Ni foam 1 M KOHElectro-depositio

n[9]

LiFe-LDH 380 - 50 104 Ni foam 1 M KOHElectro-depositio

n[9]

NiFe-LDH 300 - 50 52 Ni foam 1 M KOHElectro-depositio

n[9]

Ni-Fe LDH nanoplatelets 360 0.25 10 - Ni foam 1 M KOH

Precipitation

method[10]

Fe-CoOOH/G 330 0.196 10 37 Glassy carbon 1 M KOH Reflux

method [11]

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