Application of BiFeO3 and Au/BiFeO3 decorated kaolinite nanocomposites as efficient photocatalyst for degradation of dye and electrocatalyst for oxygen reduction reaction

Structural, optical and photocatalytic properties of Sr‐doped and Ca‐doped BiFeO3 compounds prepared by Pechini method

“…68 The textural properties of the catalyst, such as specific surface area, pore areas, pore width and pore volume, an important role in the number of active catalytic sites, adsorption abilities and photocatalytic response of the samples. 5 In this sense, conventional analysis of the N 2 adsorption-desorption isotherms was realized. The effective Brunauer-Emmett-Teller (BET) specific surface area and the estimation of the pore size distributions by the Barrett-Joyner Halenda (BJH) method were obtained.…”

“…These results indicate samples with mesoporous structure. 5,11,33 On the other hand, the BFO specimen displayed a BET area of 4.779 m 2 g −1 and this value slightly increased with the Sr and Ca addition, obtaining values up to 6.807 and 6.467 m 2 g −1 , respectively (Table 2). In addition, the Sr addition increased the pore size almost 10 times compared with the undoped sample.…”

“…Bismuth ferrite or BiFeO 3 (BFO), which has a rhombohedrally distorted perovskite structure, has been considered as a promising visible-light responsive catalyst, and in recent years scientific reports on the synthesis, characterization, and photocatalytic and doping effects of BFO have increased significantly. [1][2][3][4][5][6] This ceramic material shows a high chemical stability, lower cost and a narrow band gap of ∼2.2 eV, [7][8][9][10] which provides the possibility of using a large portion of visible light from the total solar energy. 4 However, the photocatalytic efficiency of BFO is still limited due to its low conduction band position compared to the hydrogen (or O 2 ) reduction level, small specific areas for catalytic reactions 11 and, also, impurities or secondary phases formed during the synthesis process.…”

“…21,22 Almost all the elements -La, Sm, Au, Nd, Y, Ni, Gd, Dy, Ca, Sr, among othershave been used as dopants in the crystalline structure of BiFeO 3 to modulate the optical, magnetic, optical, electronic and photocatalytic properties. 4,[23][24][25][26][27][28][29][30][31] In this sense, cations, such as Sr and Ca have shown good incorporation in the BFO structure, as well as good photocatalytic performance in the reduction of Cr(VI) 32 and the degradation of rhodamine. 33 However, usually the BFO is accompanied by secondary phases that, in photocatalysis, could present synergistic effects.…”

“…Bismuth ferrite or BiFeO 3 (BFO), which has a rhombohedrally distorted perovskite structure, has been considered as a promising visible‐light responsive catalyst, and in recent years scientific reports on the synthesis, characterization, and photocatalytic and doping effects of BFO have increased significantly 1‐6 . This ceramic material shows a high chemical stability, lower cost and a narrow band gap of ~2.2 eV, 7‐10 which provides the possibility of using a large portion of visible light from the total solar energy 4 .…”