Fabrication of stable NiO/Fe2O3 heterostructure: A versatile hybrid material for electrochemical sensing of glucose, methanol and enhanced photodecomposition and/photoreduction of water contaminants

Abstract

The p-NiO/n-α-Fe2O3 hetrostructures have been synthesized following three sequential steps. First, electrochemically NiO thin films are synthesized on FTO substrate, FeS2 thin films are then electrodeposited onto NiO surface (FTO/NiO/FeS2). On air annealing FTO/NiO/FeS2 at 600 °C results NiO/Fe2O3, a completely different heterostructure. Electrochemical study shows that the sensor (NiO/Fe2O3) has sensitivity 1437 μA mM−1 with detection limit 1.03 μM for glucose. The electrode is successfully applied to assay glucose concentration in human blood. The same electrode also exhibits prominent electrocatalytic activity to oxidise methanol in alkaline medium. The coupled semiconductor (NiO/Fe2O3) shows enhanced efficiency towards the photodecomposition of phenol and commercial dyes e.g., Congo red (CR), Rhodamine B (RhB). Again photo reduction ability of Cr(VI) is confirmed by the heterostructure which registers a remarkable reduction of toxic Cr(VI) to non toxic Cr(III). The present material can be used as a single platform to clean up the various environmental issues.