“…The FTO surface was modified with CaBi 2 Ta 2 O 9 , Bi 4 O 5 I 2 /Bi 5 O 7 I/CaBi 2 Ta 2 O 9 , BiOI or a mixture of Bi 4 O 5 I 2 /Bi 5 O 7 I/CaBi 2 Ta 2 O 9 and BiOI by employing the doctor blade technique. 26,27 Briefly, a BiOI/Bi 4 O 5 I 2 /Bi 5 O 7 I/CaBi 2 Ta 2 O 9 paste was prepared by mixing 10 mg of Bi 4 O 5 I 2 /Bi 5 O 7 I/CaBi 2 Ta 2 O 9 , 10 mg of BiOI and 30 μL of deionized water. The mixture was sonicated for 30 min.…”