Enhanced magnetic, ferroelectric and optical properties of Sr and Co co-doped BiFeO3 powders

The effects of Sr and Co doping on structural, multiferroic and optical properties were investigated in the Bi1-xSrxFe1-yCoyO3 (x, y = 0, 0.05) powders prepared by the hydrothermal method. The structure of powders changes from distorted rhombohedral for BiFeO3 to tetragonal for Bi0.95Sr0.05Fe0.95Co0.05O3. With Sr and Co doping, the particle size decreases and the surface morphology become homogeneous. A maximum magnetization of 5.66 emu/g has been achieved in the Bi0.95Sr0.05Fe0.95Co0.05O3. Sr and/or Co doped Bi1-xSrxFe1-yCoyO3 samples show enhanced ferroelectric properties. The energy band gap of Bi1-xSrxFe1-yCoyO3 has been modulated from 2.06 eV to 1.24 eV. The photocatalytic performance of the Bi1-xSrxFe1-yCoyO3 powders is represented by the degradation rate of methyl orange and the highest degradation efficiency of ∼76% is obtained in Bi0.95Sr0.05Fe0.95Co0.05O3 within 3 h under the visible light. The improved photocatalytic performance can be attributed to the reduction in band gap, the improvement of ferroelectric properties and the decrease of grain size induced by Sr and Co doping. •The pure Bi1-xSrxFe1-yCoyO3 (x, y = 0, 0.05) powders were synthesized by hydrothermal method.•The magnetic and ferroelectric properties have been improved with Sr and Co co-doping.•Doping of Sr and Co enhance the absorption of visible light and tuned band gap from 2.06 to 1.24 eV.•The highest photocatalytic efficiency was obtained in Bi0.95Sr0.05Fe0.95Co0.05O3 powders.