3D	three-dimensional
BET	Brunauer-Emmett-Teller
BTh	bithiophene
CMD	chemical manganese dioxide
CNT	carbon nanotubes
CTA	cetyltrimethylammonium
DEC	diethylcarbonate
DMC	dimethylcarbonate
DMSO	dimethyl sulfoxide
EA	electrocatalytic activity
EC	ethylenecarbonate
EDTA	ethylene diamine tetraacetate
EIS	electrochemical impedance spectroscopy
EMD	electrolytic manganese dioxide
EPR	electron paramagnetic resonance spectroscopy
EXAFS	extended X-ray absorption fine structure
FTIR	Fourier transform infrared
GNS	graphene nanosheets
GO	graphene oxide
hex.	hexagonal
HTMD	heat-treated manganese dioxide
HRTEM	high-resolution transmission electron microscopy
ICP	induced coupled plasma
ITO	indium tin oxide
MDO	manganese dioxide
MWCNT	multiwalled carbon nanotube
NHCS	N-doped hollow carbon spheres
NNs	nanoneedles
NUs	nanourchins
OMS	octahedral molecular sieve
ORR	oxygen reduction reaction
PBTh	polybithiophene
PEDOT	poly(3,4-ethylenedioxythiophene)
PEG	polyethylene glycol
PPy	polypyrrole
PTFE	polytetrafluoroethylene (Teflon)
PVA	poly(vinyl alcohol)
PVP	polyvinyl pyrrolidone
RT	room temperature
SCE	standard calomel electrode
SDS	sodium dodecyl-sulfate
SEM	scanning electron microscopy
TEM	transmission electron microscopy
TGA	thermogravimetric analysis