Ultrasonic-assisted decoration of AuNPs on carbon nano-onions as robust electrochemical scaffold for sensing of carcinogenic hydrazine in industrial effluents

Abstract

This paper describes the decoration of AuNPs on carbon nano-onions (CNO) followed by its fabrication on electrode surface for the sensitive determination of environmental pollutant hydrazine (HZ). A green ultrasonication approach was employed to decorate the AuNPs on CNOs and it follows electroless deposition. HR-TEM results reveal that spherical 10 nm-sized AuNPs were well dispersed on 30 nm-sized CNOs. The obtained 3.7 eV spin–orbit coupling in the XPS Au4f region suggests the successful decoration of Au(0) on CNO. The Au@CNO nanostructure was then directly attached on GC electrode surface by simple immersion and achieved through π–π stacking interaction and the resultant electrode exhibited high electroactive surface area and lower resistivity when compared to the CNO fabricated electrode. The Au@CNO electrode was utilized to determine HZ in effluent samples and delivered higher electrocatalytic activity by showing lower onset potential than the bare and CNO fabricated electrodes. The increased electroactive area and high electronic conductivity of Au@CNO nanostructure are attributed to the offered lowest detection limit of 12 × 10−9 M (S/N = 3) and larger sensitivity of 485.7 µA/mM cm−2. The green and environmentally benign approached Au@CNO nanostructure leads to their successful implementation in the determination of HZ in effluent samples.