ABSTRACT
Generally, preparing high-efficiency heterojunction photocatalysts via a facile room-temperature route is attractive from the perspective of energy and labor saving. Herein, by using dried and glacial acetic acid (HAc)-adsorbed bismuth nitrate, instead of Bi(NO3)3·5H2O, as a Bi source, a ß-Bi2O3/Bi5O7I heterojunction with well dispersed flowery hierarchical architecture was synthesized, which endows it with high surface area, open channels and good light harvest. More importantly, the change of the precursor achieved a successful transformation for both of phase and heterojunction type, i.e. from type-â BiOI/[Bi6O5(OH)3](NO3)5·3H2O (labeled as BiOI/BBN) to Z-scheme ß-Bi2O3/Bi5O7I heterojunction. Since both ß-Bi2O3 and Bi5O7I are visible light responsive, ß-Bi2O3/Bi5O7I exhibited improved visible-light photocatalytic activity for the degradation of tetracycline (TC) and malachite green (MG) with apparent reactant rate (kapp) values about 10 and 11 times higher than those of BiOI/BBN. Besides, the presence of more oxygen vacancies also contributed to the enhancement in photocatalytic performance.