Renewable-energy technologies are often focusing on fuel cells and metal-air batteries. And catalyst of the oxygen reduction reaction (ORR) on the cathode is key factor of the battery property. Platinum (Pt) and platinum alloys are common materials used as the catalyst. However, the high cost of Pt and declining activity limit the application.

 It is found that silver (Ag), the cheapest noble metal has catalytic activity and stability. And the electro-catalytic activities mainly depend on the nanostructure of the catalyst. Thus, Ag nanomaterials with different nanostructure are studied in recent researches.

 It has been reported that 1-dimensional (1D) Ag nanowires (NWs) shows better electro-catalytic activities than 0D Ag nanoparticles but are far from satisfactory. Previous research also found that polyoxometalates (POMs) can be used as effective reducing agents to reduce metal ions and grapheme oxide (GO) in one pot.

 Researchers with Institute of Process Engineering, Chinese Academy of Sciences firstly constructed a POM-mediated green, facile and large-scale 2D Ag nanonet(NN)/grapheme nanosheets(GNSs) nanohybrids by self-weaving of ultra-long Ag NWs with better electro-catalytic performance.

 The nanohybrids were characterized by SEM, EDXTEM, XRD, XPS and Raman spectroscopy. The as-prepared Ag NN/GNS has low vulnerability to aggregation, dissolution and Ostwald ripening and may become a good candidate of electro-catalyst for the ORR.  

 More details please see: http://pubs.rsc.org/en/content/articlehtml/2013/ta/c3ta12941a