Thermochromic behaviors of boron-magnesium co-doped BiVO4 powders prepared by a hydrothermal method

Pure BiVO4, B-doped BiVO4, Mg-doped BiVO4, and B-Mg co-doped BiVO4 were prepared using a mixed aqueous solution of bismuth nitrate (Bi(NO3)3) and ammonium vanadate (NH4VO3) using a hydrothermal method. The crystal structure and thermochromic behaviors of BiVO4 samples were investigated using X-ray diffraction, UV-Vis spectrophotometry, and in situ X-ray diffraction to compare the effects of the doping elements on the thermochromic behaviors of BiVO4. The results showed that B and Mg ions co-doped into the lattice of BiVO4 led to lattice deformation, higher impurity levels, more new band gap states, a narrower band gap, and an improvement in thermochromic behaviors than either ion alone. The thermochromic behavior of B4%-Mg4% co-doped BiVO4 was remarkably improved in comparison with the others owing to the synergistic effects of the co-doped ions.