EDTA derived graphene supported porous cobalt hexacyanoferrate nanospheres as a highly electroactive nanocomposite for hydrogen peroxide sensing

Abstract

The importance of hydrogen peroxide (H₂O₂) determination has been rapidly increasing due to its significant usage in biological and industrial applications. Hence, highly sensitive and selective sensors are required for H₂O₂ determination. This work demonstrates the development of highly sensitive electrochemical H₂O₂ sensors by using a spray exfoliated graphene and porous cobalt hexacyanoferrate nanosphere (Gr/P-CoHCF-NSPs) composite. The liquid phase high-pressure spray exfoliation technique was used to exfoliate high-quality graphene for electrochemical sensing applications. The EDTA chelation strategy was used for the homogeneous formation of P-CoHCF-NSPs on spray exfoliated graphene surfaces. The large electroactive surface area and excellent electron transfer ability of spray exfoliated graphene significantly enhanced the H₂O₂ sensing ability of the composite. The synthesized Gr/P-CoHCF-NSPs composite is highly reactive towards the oxidation of H₂O₂. The sensitivity of the fabricated sensor was 914 μA mM⁻¹ cm⁻² in a linearity range of 1 to 1000 μM. The LOD of the fabricated sensors was around 1 μM. Comparing the fabricated sensors with recently developed H₂O₂ sensors indicates a significant improvement in sensitivity and LOD. The interference study of the fabricated sensors revealed their highly selective nature towards H₂O₂ sensing. The recovery and real sample analysis of the fabricated sensors confirmed that the Gr/P-CoHCF-NSPs based H₂O₂ sensors are potential candidates for H₂O₂ detection in real samples.