Question

Transformation of waste tin-plated steel to iron nanosheets and their application in generation of oxygen

Answer 1

The rising popularity of tin-plated steel for packaging food owing to its excellent anti-corrosion properties and good strength to withstand the shipment, storage and handling leads to an environmental pollution (mainly soil and water pollution) because of their resultant disposal as waste containers. In the present study, we have designed a new process for conversion of metallic waste to iron nanosheets and utilized this material to generate oxygen, an important component of environment for sustainable life. This transformation of waste tin-plated steel to iron nanosheet (20–25 nm thick) will provide a solution to environmental pollution as well as a robust electrocatalyst for oxygen evolution reaction. Here, a single-step hydrometallurgy approach has been utilized for the transformation of waste tin-plated steel containers to iron nanosheet, and its efficiency toward the oxygen evolution reaction in alkaline condition was investigated. The results show that the nanostructured iron sheet exhibits better properties as a electrocatalyst for oxygen evolution reaction in terms of the onset overpotential of O2 evolution (~ 329 mV) in comparison with the bulk iron (~ 500 mV) as well as iron-based alloy (Fe33Co67, ~ 400 mV). Thus, in the present investigation, the transformation of an efficient electrocatalyst for oxygen evolution reaction, which is a value-added product from waste scrap, has been achieved at low cost. The above process is quite economical and can be easily extended for large-scale productions of the robust electrocatalyst for oxygen evolution reaction.