AgI Nanoparticles Decorated Bi 24 O 31 Br 10 Nanosheets: An Efficient 0D/2D Z-Scheme Heterojunction Photocatalyst for the Degradation of Rhodamine B

A novel 0D/2D Z-scheme AgI/Bi 24 O 31 Br 10 photocatalyst was prepared through the simple solvothermal and coprecipitation method, in which AgI nanoparticles were decorated on the surface of Bi 24 O 31 Br 10 nanosheets. The AgI/Bi 24 O 31 Br 10 composites exhibited improved photocatalytic activity for the degradation of rhodamine B (RhB) in comparison with pristine Bi 24 O 31 Br 10 and AgI under simulated sunlight irradiation. Specifically, AB-30 (mass fraction of AgI, 30%) composite exhibited remarkable photocatalytic activity of 97.6% towards RhB degradation under 120 min of simulated sunlight irradiation, and its RhB degradation rate constant ( k ) was approximately 20.7 and 2.9 times higher than that of pure Bi 24 O 31 Br 10 and AgI, respectively. The improvement of photocatalytic performance of as-prepared AgI/Bi 24 O 31 Br 10 heterojunction composites was ascribed to the synergistic effect of wide visible-light harvest capacity and the rapid transfer and separation efficiency of charge carriers. UV–vis diffuse reflectance spectra (DRS) analysis validated that the introduction of AgI could broaden the visible-light absorption of AgI/Bi 24 O 31 Br 10 composite. The results of electrochemical impedance (EIS), photocurrent response and photoluminescence spectra (PL) tests showed that AgI/Bi 24 O 31 Br 10 composite possessed the efficient separation and migration of photogenerated charge carriers. Trapping experiments of free radicals certified that ·O 2 − was the main reactive species in the process of degradation. And a probable photocatalytic mechanism of Z-scheme heterojunction between Bi 24 O 31 Br 10 and AgI was proposed.