Structurally and Compositionally Tunable Absorption Properties of AgCl@AgAu Nanocatalysts for Plasmonic Photocatalytic Degradation of Environmental Pollutants

Abstract

Composite nanomaterials having Ag nanoparticles (NPs) that decorate nanostructured AgCl (Ag/AgCl) are promising as plasmonic photocatalysts because of the visible-light absorption of Ag NPs. However, the narrow absorption bands of Ag NPs near 400 nm cause inefficient absorption in the visible range and, consequently, unsatisfactory photocatalytic activity of Ag/AgCl nanomaterials. In this study, we introduce a new class of AgCl-based photocatalysts that are decorated with bimetallic Ag and Au NPs (AgCl@AgAu NPs) for visible-light-driven photocatalytic degradation of organic pollutants. Polyvinylpyrrolidone induces selective reduction of noble metal precursors on AgCl while leaving AgCl intact. The extended composition of the decorating NPs red-shifts the absorption band to 550–650 nm, which allows the catalysts to take advantage of more energy in the visible range for improved efficiency. Furthermore, we control the structures of the AgCl@AgAu NPs, and investigate their correlation with photocatalytic properties. The versatility, chemical stability, and practical application of the AgCl@AgAu NPs are demonstrated using various organic pollutants, recycling experiments, and natural aqueous media, respectively. Our fundamental investigation on the synthesis and applications of AgCl-based nano-photocatalysts is highly valuable for designing plasmonic photocatalysts and expanding their utilization.

Unveiling the Role of Precursors in the Byproduct Formation of AgCl-Replicated Bimetallic Nanostructures and Their Stability-Dependent Photothermal Properties

“…Although there are several reports on AgCl nanostructures with AuCl 4 – , to the best of our knowledge, this is the first report associated with the undesired formation of AgCl debris from a mixture of the AgCl NCs and AuCl 4 – , as the tiny size and small quantity of debris make its identification highly challenging. 1 , 6 , 10 The CMNs collapse after the removal of the template possibly due to a deficiency of Au that was partially consumed during the formation of byproduct NPs. In Figure 4 b, we propose a fundamental solution to this issue using a new ligand-exchanged Au precursor, Au(NH 3 ) 4 3+ , which is less oxidative and contains no halogen element.…”

“…Recently, AgCl nanoparticles (AgCl NPs) have received increased interest as efficient structural building blocks for the synthesis of nanomaterials with controlled shapes and sizes. − Many multimetallic nanomaterials are currently synthesized by constructing three-dimensional cubic and spherical mesh nanostructures using AgCl NPs as templates due to the excellent chemical and physical properties of AgCl, such as rapid and facile synthesis at room temperature, controllable shapes and sizes, and cost-effectiveness. , Easy removal of the AgCl template with a dilute NH 3 solution is a significant advantage in a sacrificial template compared to other inorganic and organic nano-templates. Moreover, AgCl itself can play a role as a reactive Ag precursor under precise chemical control, which significantly increases interfacial fabrication between the template and metallic replica.…”

Nanomaterials in Photo (Electro) Catalysis

“…Experimental results from the paper of Ryu et al describe a valuable approach to control the reduction of metal ions, thus controlling the plasmonic properties of the nanostructure. Further, the correlation between the structural, compositional, and photocatalytic properties of AgCl-based nanomaterials is demonstrated [15].…”