Chemical modification of waste Allium cepa peels to Cu-complex composite and application as eco environmental oilfield anticorrosion additive

A new bio-based complex composite material (Cu-EtCPLX) has been synthesized from agricultural waste by chemical treatment of Allium cepa peels ethanol extract with aqueous copper salt at 50 °C. The bio-composite was characterized by UV–Vis, FTIR, DLS, XRD, SEM/EDS and TEM. The efficiency of the composite as anticorrosion additive to oilfield pickling fluid was investigated. Electrochemical and weight loss techniques were used to monitor corrosion process and determine the corrosion rate and inhibition efficiency. Cu-EtCPLX exhibits higher adsorptive capacity on X80 steel surface through its CC and O–H groups, was thermally more stable and efficient in inhibiting steel corrosion in 1 M HCl by 95.8% and 87.2% at 30 °C and 60 °C, respectively. The bio-composite is a mixed type corrosion inhibitor and reduces surface roughness and piting by 56.3% and 70.7% respectively. Corrosion products, mechanism and extent of surface were probed by FTIR, SEM/EDS and AFM techniques. Cu-EtCPLX is a promising highly efficient bio-composite that could be used as green, cheap and sustainable alternative anticorrosion additives for oilfield acid pickling and descaling solutions.