Preparation of Z-scheme AgI/Bi5O7I plate with high visible light photocatalytic performance by phase transition and morphological transformation of BiOI microspheres at room temperature

AgI/Bi5O7I plate composite was fabricated at room temperature by the phase transition and morphological transformation of BiOI microspheres. The orange BiOI microsphere was transferred to light yellow AgI/Bi5O7I plate by the addition of NaOH and AgNO3 to the system. The formation process and possible transformation mechanism of AgI/Bi5O7I plate were detected and are discussed. The visible light absorption area of AgI/Bi5O7I extended to 667 nm and photo-excited electrons migrated from Bi5O7I to AgI to effectively inhibit the recombination of photo-generated carriers in the Z-scheme AgI/Bi5O7I plate. As a result, the photocatalytic ability of AgI/Bi5O7I plate increased by a factor of 21.9 than that of pure Bi5O7I and a factor of 45.7 than that of pure AgI under visible light irradiation. This study provides a facile fabrication of Z-scheme visible light photocatalysts with high performance and a method for designing semiconductor photocatalysts with controllable morphology.