Process optimization for biosynthesis of mono and bimetallic alloy nanoparticle catalysts for degradation of dyes in individual and ternary mixture

Abstract

Nanoparticle (NP) catalysts are widely used for removal of dyes for single use, but there is an acute need for developing catalysts with high efficiency and reusability for mixed dyes. Here we first optimized the process (reactant proportion, temperature, time, and pH) for biosynthesis of monometallic Ag, Au and bimetallic Au-Ag alloy NP catalysts using Polyalthia longifolia leaf extract. The biosynthesized NP catalysts were characterized by UV-vis, DLS, Zeta potential, TEM and EDX study while the probable biomolecules responsible for biosynthesis were identified by FTIR and GC-MS/MS analysis. The NPs are found to be mostly spherical in shape (size 5-20 nm) with prolonged stability. We evaluated their chemo-catalytic performance through degradation of dyes (methyl orange, methyl violet, methylene blue) in individual and ternary mixture in presence of NaBH 4. The degradation percentage (80.06-96.59% within 5 min), degradation kinetics (k = 0.361-1.518 min-1), half-life (T 50 = 0.457-1.920 min) and 80% degradation (T 80 = 1.060-4.458 min) of dyes indicated highest catalytic activity of alloy in ternary mixture. Here we report a unique vacuum filtration system using alloy coated beads with excellent catalytic activity which could be reused thrice for removal of hazardous ternary mixed dyes with great promise for environmental remediation.

Development of Multifunctional Pullulan/Chitosan-Based Composite Films Reinforced with ZnO Nanoparticles and Propolis for Meat Packaging Applications

“…The Z avg and PDI were 451.3 ± 24.8 nm and 0.36 ± 0.01, respectively (Figure S1, Supporting Information), demonstrating the development of monodispersed nano-sized particles. The stability of the nanoparticles in an aqueous condition was checked by zeta potential, and the obtained data (−25.2 ± 0.5 mV, Figure S1, Supporting Information) revealed the moderate stability of the nanoparticles [42,43]. The stability of the ME-capped ZnONPs solution was very similar to the earlier reported melanin-mediated ZnONPs [30].…”

Plasmonic Gold Nanoparticles (AuNPs): Properties, Synthesis and their Advanced Energy, Environmental and Biomedical Applications

“…Finally, there are few vital reviews and articles, which comprehensively describe the utilization of plasmonic AuNPs in various photocatalytic, [7] energy (hydrogen through photocatalytic and photoelectrocatalytic water splitting) [35,36] , and environmental applications (water decontamination, etc.). [37][38][39] In continuation of these efforts, the current review is mainly focusing on the various routes which can be efficiently used for the synthesis of AuNPs, and to tune their plasmonic properties. The later part of the review also summarizes a few vital applications for the interest of the readers.…”

Microwave assisted synthesis of zinc oxide (ZnO) nanoparticles in a noble approach: utilization for antibacterial and photocatalytic activity

“…The photocatalytic degradation and rate of degradation of MB aqueous solution was calculated by the Eqs. (8) and (9) respectively [36].…”