Investigation of co-doped magnetite (Fe3O4) nanomaterials with reduced graphene oxide and bismuth for photocatalytic, supercapacitor, and antimicrobial applications

Abstract

The present study reports the successful preparation of pure magnetite Fe3O4 (F), bismuth doped Fe3O4 (FB), reduced graphene oxide doped Fe3O4 (FR), and bismuth-rGO co doped Fe3O4 (FBR) using the simple co-precipitation process. The produced samples were subjected to morphological, optical, FTIR, and structural analyses. XPS- Photo electron spectroscopy indicates the presence of relevant elements and oxidation states. BET surface analysis shows the presence of enhanced surface area in conjointly doped Fe3O4 (FBR) and rGO doped Fe3O4 (FR). The photocatalytic activity of the materials (F, FB, FR, and FBR) against several organic dyes [MB, Rho-b, and Congo red (CR)] was investigated. Using the disc diffusion method, the antibacterial activity of the samples was investigated against a variety of gramme positive and gramme negative bacteria. The findings indicate that the co-doped magnetite nano composite exhibits strong antimicrobial activity. The synthesised materials were also used as electrode materials for supercapacitors. The electrochemical performance of the FBR-based supercapacitor was reliable, and it exhibited a high specific capacitance of 732.51 Fg-1 at a current density of 1 Ag-1. From the CV analysis, the measured capacitance was 440.67 Fg-1 for a three-electrode configuration. The symmetric device has been constructed using bismuth and rGO co doped (FBR) nano composite and it exhibited a specific capacitance of 173 Fg-1, specific energy of 24 W h Kg1, and specific power of 1999 W Kg-1 at a current density of 1 Ag-1 with notable cyclic stability of about 89 % and had average capacity retention and excellent coulombic efficiency which is about 95 % up to 8000 cycles which is retained even after 18,000 cycles.