Metal-organic framework-derived rodlike AgCl/Ag/In2O3: A plasmonic Z-scheme visible light photocatalyst

Abstract A novel metal-organic framework (MOF)-derived rodlike AgCl/Ag/In2O3 plasmonic photocatalyst has been successfully prepared by electrostatic self-assembly, co-precipitation, in-situ photoreduction, and calcination. The photocatalytic activity of the samples was systematically investigated by photocatalytic tetracycline (TC) oxidation and Cr(VI) reduction under visible light irradiation. Among the as-prepared samples, AgCl/Ag/In2O3-2 displayed the most effective photocatalytic activity. For photocatalytic TC oxidation, the apparent rate constant of AgCl/Ag/In2O3-2 was 0.5036 min-1, which was 2.7, 6.5, and 1.8 times higher than that of In2O3 (0.1845 min-1), AgCl/In2O3 (0.1544 min-1) and Ag/In2O3 (0.2850 min-1), respectively. In addition, AgCl/Ag/In2O3-2 also exhibited the highest activity for photocatalytic Cr(VI) reduction, and the photocatalytic Cr(VI) reduction rate of AgCl/Ag/In2O3-2 in 3hrs could reach 94.8%. The superior photocatalytic activity was due to the enhanced absorption in the visible light region caused by localized surface plasmon resonance (LSPR) and the efficient interfacial charge migration and separation in AgCl/Ag/In2O3 samples. Moreover, the intermediates formed in the photocatalytic TC oxidation were identified by GC-MS. Finally, a series of characterizations and simulations (density functional theory, cambridge serial total energy package, and finite difference time domain) were carried out to demonstrate the plasmonic Z-scheme photocatalytic mechanism.