Controlled synthesis and enhanced toluene-sensing properties of mesoporous NixCo1-xFe2O4 nanostructured microspheres with tunable composite

The mesoporous NixCo1-xFe2O4 (x = 0, 0.33, 0.50, 0.67) nanostructured microspheres with tunable composite were successfully controllable synthesized by a simple solvothermal method. The results of XRD, XPS and FT-IR demonstrated that the Ni, taking the place of Co, were successfully doped into CoFe2O4. The gas sensing results demonstrated that the Ni0.33Co0.67Fe2O4 nanostructured microspheres showed higher gas-sensing response and better selectivity to harmful toluene than that of other samples. Moreover, the influences of Ni-doping amount on the structure, morphology and gas-sensing property of NixCo1-xFe2O4 were investigated. The enhanced gas-sensing properties of gas sensor based on Ni0.33Co0.67Fe2O4 to toluene may be due to appropriate Ni-doping into cobalt ferrite which resulted in the increased concentration of oxygen vacancies, large specific surface area (77.2 m2 g−1) and suitable catalytic activity. Therefore, the NixCo1-xFe2O4 will be a promising candidate for gas-sensing material for detecting toluene.