TiO2 nanoparticles supported on N–S co-doped rGO as electrocatalyst for non-enzymatic H2O2 sensing

A novel enzyme-free H 2 O 2 electrochemical sensor based on the anatase form of TiO 2 nanoparticles modified on N–S doped reduced graphene oxide (ATNPs@NS-rGO) was synthesized hydrothermally with one step. ATNPs@N-rGO was also synthesized to study the effect of S atom on sensor performance. Raman spectroscopy, X-ray Powder Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), and mapping were used to characterize catalysts. In addition, electrochemical measurements such as cyclic voltammetry (CV), amperometric measurements, and electrochemical impedance spectroscopy (EIS) were performed to investigate the performance of catalysts in the reduction of H 2 O 2 . Both the synergistic effect between the S atom and ATNPs and the fact that the graphene layer has more defect regions thanks to the S atom caused ATNPs@NS-rGO to gain superior catalytic activity for the reduction of H 2 O 2 . According to the amperometric measurements, the ATNPs@NS-rGO electrode showed a wide linear range for H 2 O 2 from 2 to1000 µM with a high sensitivity of 188.75 µA mM −1 cm −2 and a detection limit of 0.019 µM. Graphical abstract