Chemically reduced silver nanoparticles towards photocatalytic and electrocatalytic applications

In virtue of unique physiochemical properties, silver nanoparticles (AgNPs) have attracted enormous research interest for versatile applications. It is critical to study the effect of the microstructure, e.g., the shape and the size of AgNPs on their performance. Herein, AgNPs with varying shapes and sizes were synthesized by varying the manner of the reducing agent NaBH4 added (i.e., multi-step and one-step reduction methods), and then were studied for photocatalytic of dyes and electrocatalytic oxidation of glucose. The results showed that triangular, spherical, or the mixture of triangular/spherical shaped AgNPs were obtained from multi-step reduction method, whereas only spherical shaped AgNPs were yielded from the one-step reduction method. The sizes could be manipulated by changing the concentrations of the reagents or the reaction temperature. The triangular shaped and smaller-sized AgNPs were more effective for photocatalytic of dyes, and the degradation percent of methylene blue was enhanced to 95% for the Ag-TiO2 complex from 50% for pure TiO2. Moreover, the spherical shaped AgNPs with smaller size could effectively detect glucose at a very low concentration of 5 to 10 mM with an excellent glucose tolerance.