Simplified synthesis of silver nanoparticles on graphene oxide and their applications in electrocatalysis

Abstract

In this work the possibility was investigated to synthesize in-situ silver nanoparticles (AgNP) on graphene oxide (GO) surface without commonly used additional reducing or alkalizing agents or increased temperature. Using diverse microscopic (AFM, TEM) and spectroscopic methods, it was proved that very small AgNPs were formed on GO by simple incubation for 2 hours a mixture of GO dispersion and AgNO3. The prepared nanomaterial (GO_Ag) was also assessed using electrochemical methods and it exhibited electrochemical behavior similar to GO_Ag nanomaterial prepared with a help of citric acid as a reducing agent. Furthermore, it was found that i) electrochemical reduction of the GO_Ag on electrode surface decreased the voltammetric response even though this step has increased the surface conductivity and ii) GO_Ag can be employed for sensing of chlorides with detection limit of 79 M and a linear range up to 10 mM. It could also provide electrochemical response toward chloroacetanilide herbicide metazachlor. Hence, the reducing capabilities of GO were proved to be applicable for insitu synthesis of metal nanoparticles with the highest possible simplification and the as-prepared nanomaterials could be employed for fabrication of different electrochemical sensors.

Silver Integrated with Carbonaceous 2D Nanomaterials as an Electrocatalyst for Reductive Dechlorination of Chloroacetanilide Herbicide

“…Another interesting result is the emergence of absorption bands at about 1080 cm -1 (C-O in alkoxy group [68][69][70] ) observed in GO_AgNP and ErGO_AgNP samples with much higher intensity than in GO and ErGO sample (in the latter one, this band diminished entirely). It may sound in the contradiction with previous findings 54 where incubation of GO with Ag + was accompanied by decrease of 1080 cm -1 band. However, it should be noted that the samples here were measured on films pealed-off from the carbon electrode surfaces, not only deposited on aluminium foil.…”

“…This fact may suggest thatthe prolonged incubation leads to the integration of silver also into the inner structure of MXene particles/agglomerates. It should be noted that the same method revealed only about 0.2 % (w/w) of silver in GO_AgNP material 54 .…”

“…The calculated size also corresponds well with those reported by Zou et al 59 . Interestingly, the typical XRD peaks were not detected in any GO_AgNP sample (data not shown), most probably as a result of their small size 54 .…”

“…They can also attach positively charged metal ions, which is known to promote the rate of in-situ metal nanoparticle synthesis. In fact, graphene oxide has been also determined as the possible agent for reduction of metal ions, as investigated in our previous study 54 and elsewhere. Therefore, similarly to MXene-metal nanoparticles nanohybrides, graphene oxide has been also employed for synthesis of GO-metal nanoparticles hybrid nanomaterials which exhibited good electrocatalytic properties.…”

“…Examples include Au nanoparticles decorated GO employed for determination of chloramphenicol (no dechlorination, but reduction of nitro-group observed) 55 , Pd/GO/Ti nanohybrid employed for electrodegradation of 2,4-dichlorophenol 56 or GO-Ag nanoparticles for detection of hydrogen peroxide 57 . Furthermore, in our previous study it was found that silver nanoparticles deposited on the surface of electrochemically reduced graphene oxide can provide electrochemical signal related to metazachlor dechlorination, but without a focus on its quantitative determination 54 .…”