Sustainable preparation of AuAg alloy@AgBr Janus nanoparticles via dissipative self-assembly for photocatalysis

We report a facile synthesis of cetyltrimethylammonium bromide (CTAB) templated AuAg alloy@AgBr Janus-nanoparticles (JNPs) using a non-conventional top-down approach with precise control over symmetry breaking. The addition of AgNO3 to a micellar solution of CTAB results in micelle-stabilized AgBr colloids having excess Ag+ at the interstitial sites of AgBr. AgBr colloids undergo weak self-assembly supported by inter-micellar interactions. The interfacial disturbance of self-assembled colloids via electrostatic adsorption of AuCl4- or Au(OH)4- at the micelle-AgBr interface downsizes the colloids. This is followed by the growth of the AuAg phase onto AgBr resulting in AuAg alloy@AgBr JNPs via different reduction pathways (photoreduction or chemical reduction) in the presence of ascorbic acid. The prepared JNPs act as efficient visible light photocatalysts for the degradation of aqueous rhodamine B. Interestingly, the trapping of holes favors the photocatalytic efficiency. Furthermore, the JNPs have shown proficiency in inhibiting the growth of both Gram-positive and Gram-negative bacteria as compared to the commercial antibiotic kanamycin, with a very low MIC value of ∼35 μg ml-1. In this way, a new single-pot strategy for the controlled preparation of photo-catalytically active and antimicrobial AuAg alloy@AgBr JNPs governed by dissipative self-assembly is reported for the first time.

Synthesis of Positively Charged Photoluminescent Bimetallic Au-Ag Nanoclusters by Double-Target Sputtering Method on a Biocompatible Polymer Matrix

Herein, we report a novel positively charged photoluminescent Au-Ag bimetallic nanocluster synthesized using 11-mercaptoundecyl-N,N,N-trimethylammonium bromide as the capping ligand by means of "green" double-target sputtering method on a biocompatible polymer matrix. The photoluminescent Au-Ag bimetallic cluster showed emission tunability from blue to near infrared (NIR) regions with respect to change in the composition.

Singlet oxygen formation in bio-inspired synthesis of a hollow Ag@AgBr photocatalyst for microbial and chemical decontamination

Singlet oxygen has been identified as a contributor to the degradation of contaminants using biosynthesised hollow Ag@AgBr catalysts.

Synthesis of cationically charged photoluminescent coinage metal nanoclusters by sputtering over a liquid polymer matrix

A generic green synthetic approach to synthesize photoluminescent metal nanoclusters of known plasmonic elements via sputtering on a biocompatible polymer matrix.