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Here,Ag_2S nanoparticles on reduced graphene oxide(Ag_2S NPs/RGO) nanocomposites with relatively good distribution are synthesized for the first time by conversing Ag NPs/RGO to Ag_2S NPs/RGO via a facile hydrothermal sulfurization method.As an noval catalyst for the reduction of 4-nitrophenol(4-NP),it only takes 5 min for Ag_2S NPs/RGO to reduce 98% of 4-NP,and the rate constant of the composites is almost 13 times higher than that of Ag NPs/RGO composites.The high catalytic activity of Ag_2S NPs/RGO can be attributed to the following three reasons:(1) Like metal complex catalysts,the Ag_2S NPs is also rich with metal center Ag(δ~+),with pendant base S(δ) close to it,and thus the Ag and basic S function as the electron-acceptor and proton-acceptor centers,respectively,which facilitates the catalyst reaction;(2)RGO features the high adsorption ability toward 4-NP which provides a high concentration of 4-NP near the Ag_2S NPs;and(3) electron transfer from RGO to Ag_2S NPs,facilitating the uptake of electrons by 4-NP molecules.
Here, Ag_2S nanoparticles on reduced graphene oxide (Ag_2S NPs / RGO) nanocomposites with relatively good distribution are synthesized for the first time by conversing Ag NPs / RGO to Ag_2S NPs / RGO via a facile hydrothermal sulfurization method. As no no catalyst for the reduction of 4-nitrophenol (4-NP), it only takes 5 min for Ag_2S NPs / RGO to reduce 98% of 4-NP, and the rate constant of the composites is almost 13 times higher than that of Ag NPs / RGO composites. The high catalytic activity of Ag_2S NPs / RGO can be attributed to the following three things: (1) Like metal complex catalysts, the Ag_2S NPs is also rich with a metal center Ag (δ ~ +), with pendant base S to it, and thus the Ag and basic S functions as the electron-acceptor and proton-acceptor centers, respectively, which facilitates the catalyst reaction; (2) RGO features the high adsorption ability toward 4-NP which provides a high concentration of 4 -NP near the Ag_2S NPs; and (3) electron transfer from RGO to Ag_2S NPs, facilitating the uptake of electrons by 4-NP molecules.