Electrochemical and Thermodynamic Investigation on Corrosion Inhibition of C38 Steel in 1M Hydrochloric Acid Using the Hydro-Alcoholic Extract of Used Coffee Grounds

Table 7

Different investigated coffee extracts as an inhibitor for steel corrosion in 1 M HCl medium.

Inhibitor	Concentration (g/L)	Inhibition efficiency (%)	Inhibitor type	Reference
Aqueous roasted coffee extract	1	84	Mixed	[69]
Coffee husk aqueous extract	0.5	84.1	Mixed	[68]
Aqueous coffee ground extract	0.4	88.1	Mixed	[25]
Hydro-alcoholic extract of used coffee grounds	0.25	91	Mixed	Present work