Surfactant-free gold nanoparticles: rapid and green synthesis and their greatly improved catalytic activities for 4-nitrophenol reduction

It is highly desired but still remains a key challenge to develop a simple and green strategy for greatly improving the catalytic activity of catalysts. In this communication, surfactant-free gold nanoparticles (sf-AuNPs) were quickly synthesized (<30 s) using reductive carbon dots (r-CDs) instead of traditional surfactants; this is the fastest strategy for sf-AuNP synthesis based on r-CDs without using a strong reductant and protective agent. What's more, the catalytic activity of sf-AuNPs/r-CDs for the 4-nitrophenol reduction is greatly improved due to the surfactant-free properties and the synergistic effects of AuNPs and r-CDs. Our work would open up a new avenue for the design of catalyst materials with high performance and catalytic activity.