Facile sonochemical synthesis of silver nanoparticle and graphene oxide deposition on bismuth doped manganese oxide nanotube composites for electro-catalytic sensor and oxygen reduction reaction (ORR) applications

Pristine silver nanoparticles and silver-graphene oxide nanoparticles have incorporated in Bismuth doped manganese oxide (Bi-MnOx) nanotubes by an ultra-sonication deposition method. Pristine Bismuth doped porous MnO2 has prepared by a non-ionic surfactant (Triton-X-100) assisted co-precipitation and heat treatment process. In the second stage, the biogenic method prepared very fine Ag nanoparticles with a quantum dot size of particles (below 10 nm). They have further deposited on the dried powder of Bi-MnOx by ultra-sonication fabricate the composite material for electrode application. The pure nanotube formation obtained for silver nanoparticle deposited Bi-MnOx (Ag-BiMnOx) and silver/GO nanoparticle(Ag-BiMnOx/GO) nanocomposites have clearly confirmed by high resolution transmission electron micrographs (HR-TEM). The nanotube diameter obtained in the range of 10–25 nm and length of nanotube obtained in the rage of 40–50 nm. Enhanced thermal stability has achieved for Ag-BiMnOx and Ag-BiMnOx/GO composite compared to pristine manganese oxide. Band gap values of prepared compoiste is calculated from Diffuse reflectance spectral data provide the bandgap values of Ag–Bi-MnOx/GO (1.93 eV) and Bi-MnOx (2.47 eV). As prepared graphene oxide modified Bi-MnOx composite modified electrode have further analyzed for hydrogen peroxide sensor and Oxygen reduction reactions (ORR). Silver nanoparticle-graphene oxide modified Bi-MnOx composite shows an enhanced electrochemical capacitance activity of 2.61 mF and improved electrochemical surface area of 65.25 cm2 towards clean energy technology application. [Display omitted] •Silver nanoparticle/GO deposition on Bi-MnOx nanotube prepared by ultrasonication.•Ag QDs and graphene sheets inserted into the nanotube of Bi-MnOx.•Ag-BiMnOx/GO shows enhanced capacitance activity of 2.61 m.•Ag-BiMnOx/GO shows higher electrochemical surface area of 65 m2.•Ag-BiMnOx/GO shows 4e− oxygen reduction process similar like Pt/C electrode..