Preparation, Characterization, and Photocatalytic Performance of Ag/BiOBr_0.85I_0.15 Nanocomposites

Abstract

In the present paper, a series of Ag/BiOBr0.85I0.15 composite nanoparticles with different silver loading were prepared by a combined solvothermal and photocatalytic reduction method. The composite samples have been characterized by XRD, XPS, SEM, EDX, TEM, UV-Vis, and N2 adsorption/desorption techniques. The characterization results showed that BiOBr0.85I0.15 composite nanoparticles have a tetragonal phase structure. Silver nanoparticles are uniformly distributed on the BiOBr0.85I0.15, which results in surface plasmon resonance absorption, effectively increasing the visible light absorption ability of BiOBr0.85I0.15. The photocatalytic activity of the samples was evaluated by photocatalytic degradation of ammonia nitrogen in circulating aquaculture water under simulated sunlight irradiation. The effect of the Ag loading amount on the photocatalytic degradation of ammonia nitrogen was investigated. Silver loading of 1% (molar ratio) can effectively improve the degradation capacity of the catalyst for ammonia nitrogen in water. The recycling experiments show that 1%Ag/BiOBr0.85I0.15 has good photocatalytic stability. ESR characterization and oxidation species scavenging experimental results suggest that h+, 1O2, and ·O2− are the main oxidizing species in the photocatalytic system.

Keywords

• Ag/BiOBr_0.85I_0.15
• silver loading
• photocatalysis
• ammonia nitrogen degradation