Corrosion is the destruction of metal surface by the
reaction with its environment (humidity, gases, acid, alkaline
etc.). In this process metal convert in to the more stable form
such as sulphide oxide etc. Corrosion of materials and
structures is a hindrance to the development of society as it
causes significant loss to the economy, leads to pollution, and
leads to serious disasters, hence its prevention and control is
of great benefit for the humanity. Addition of corrosion
inhibitors is one of the practical and easy methods to protect
metals and alloys against attack of corrosion in many industrial
environments. In this chapter thiosemicarbazide based Schiff
base 2-[(3,4-dihydroxy-5-nitrophenyl)methylidene]hydrazine1-carbothioamide (DHNPMHC) was synthesized and
characterized using elemental analysis, FT-IR and UV–Vis
methods. The inhibition efficiency of Schiff base DHNPMHC
against aluminium corrosion in 0.5 M HCl was examined using
mass loss measurement and scanning electron microscopy
(SEM). Results showed that DHNPMHC is an effective
inhibitor for aluminium corrosion in 0.5 M HCl solution. The
inhibition efficiency also increased with concentration of
inhibitor increased. Maximum percentage inhibition efficiency
92.6 % (at 4-hour immersion time) is shown at highest
concentration of inhibitor 5% (5X10-5M). Adsorption of the
inhibitor on the aluminium surface followed Langmuir
adsorption isotherm. SEM study of aluminium surface in
presence of inhibitor and in absence of inhibitor also supports
the inhibition of corrosion in acidic medium. All results show
that the Schiff base of thiosemicarbazide (DHNPMHC) is
excellent corrosion inhibitor for aluminium in 0.5 M HCl.