Table 2.

Overview of range of 2D nanomaterials for electrocatalytic applications

2D nanomaterials	Synthesis	Application	Conditions	Performance or parameter	Activity origin or mechanism	Refs
Double-gyroid MoS2	Electrodeposition, followed by sulfidization	HER	Acidic medium	Overpotential = 150–200 mV Tafel slope = 50 mV decade−1	Surface embellishment for edge site exposure	[35]
Co3S4	Physical etching	HER	Alkaline medium	Ƞ10 = 63 mV Tafel slope = 58 mV decade−1	Abundant sulfur vacancies	[340]
Co–N-GA	Solvothermal	HER	Acidic medium	Onset = 0 V, Ƞ10 = 46 mV Tafel slope = 33 mV decade−1	Synergetic effect of N-doped carbon and inner metal Co	[306]
MoS2	Hydrothermal	HER	Acidic medium	Ƞ-200 = 198 mV Tafel slope = 36 mV decade−1	Facilitated ion diffusion by channel engineering	[36]
WSe2	Hydrothermal	HER	Acidic medium	Onset = 150 mV Tafel slope = 78 mV decade−1	Many exposed edge sites can provide abundant active reaction sites	[186]
Mo2CTx	Ball milling, HF etching	HER	Acidic medium	Ƞ10 = 189 mV Tafel slope = 70 mV decade−1	Tx as surface functional groups	[287]
NiFe-LDH	Ultrasonication	OER	Alkaline medium	Ƞ10 = 254 mV Tafel slope: 32 mV decade−1	Metal and oxygen vacancies	[216]
Ni–Fe-MOF	Solvothermal	OER	Alkaline medium	Ƞ10 = 221 mV Tafel slope = 56 mV decade−1	Fe constitutes the active site	[307]
CoFe LDH	Hydrothermal and Water-plasma-enabled exfoliation	OER	Alkaline medium	Ƞ10 = 232 mV Tafel slope = 36 mV decade−1	As-exfoliated increased active sites and multi-vacancies	[215]
CoCo-LDH	Soft template method	OER	Alkaline medium	Ƞ10 = 319 mV Tafel slope = 42 mV decade−1	More highly active edge sites with lower coordination number and mass diffusion promotion	[346]
Ni(OH)2	Chemical etching	OER	Alkaline medium	Ƞ10 = 335 mV Tafel slope = 65 mV decade−1	Holes developed inside the sheet structure supply tremendous permeable channels for ions adsorption and transportation	[344]
BP	Liquid phase exfoliation	OER	Alkaline medium	Onset = 1.45 V, Ƞ10 = 300 mV Tafel slope = 88 mV decade−1	Reduction in thickness generates active sites and improves specific surface area	[283]
Ni-MOF@Fe-MOF	Ultrasonication	OER	Alkaline medium	Ƞ10 = 265 mV Tafel slope = 82 mV decade−1	Hybridization and cooperativity between Ni and Fe	[289]
Co-C3N4/CNT	Polycondensation reactions, and acid leaching process	ORR and OER	Alkaline medium	HER onset = 0.9 V, OER onset = 1.5 V Tafel slope = 68.4 mV decade−1	M-N2 coordination	[171]
Fe-Co/N-rGO-Al	Solvothermal	ORR	Alkaline medium	Onset = 0.98 V half-wave potential = 0.84 V	Four electron transfer mechanism and a lower HO2− yield	[347]
Pd	Thermal treatment	ORR	Alkaline medium	Mass activity (0.85 V) = 21.1 mA mg−1 electron transfer number = 3.73–3.85	Unique structural features	[237]
WSe2	Chemical vapor transportation	CO2RR	Acidic media	Current density = 18.95 mA cm−2 CO formation turnover frequency = 0.28 s−1 Overpotential = 54 mV	Presence of ionic liquids and high density of edges	[349]
Ru/MgAl	Wet impregnation	CO2RR	Gas phase reaction	CO2 conversion = 85% CH4 yield = 84%	Non-thermal plasma (NTP) activated CO2 hydrogenation	[348]