AgI nanoparticles decorated Bi3O4Cl microspheres: An efficient Z-scheme heterojunction photocatalyst for the degradation of rhodamine B and tetracycline

A novel Z-scheme AgI/Bi3O4Cl composite was fabricated through solvothermal-calcination method followed by an in-situ deposition process. The AgI/Bi3O4Cl composites exhibited improved photocatalytic activity for degrading rhodamine B (RhB) and tetracycline (TC) in comparison with pristine Bi3O4Cl and AgI under simulated sunlight irradiation. Specifically, BAI-3 composite (mass content of 30% of AgI) showed the highest removal efficiency of RhB and TC. And the degradation rate constants (k) of RhB over BAI-3 was 0.038 min(-1), which was 25.3 and 3.8 times than that of pristine Bi3O4Cl (0.0015 min(-1)) and AgI (0.01 min(-1)), respectively. The photoelectrochemistry measurements and photoluminescence (PL) spectra manifested that the recombination of photogenerated electrons and holes in AgI/Bi3O4Cl composite was suppressed evidently because of the construction of AgI/Bi3O4Cl heterojunction. Radicals trapping experiments and electron spin resonance (ESR) test showed that center dot O-2(-) and h(+) were the main reactive species. Combined with the analysis of band structures, a Z-scheme charge transfer mechanism of AgI/Bi3O4Cl composite was confirmed.