Construction Of C-PANI@PtAg/Pt And Its Performance As A Dual Electrocatalyst

Looking for new renewable material is intensely research topic to solve the current energy and environmental crisis.High-efficiency electrochemical energy conversion,a renewable energy conversion and storage system is receiving more and more attention.Formate oxidation reaction(FOR)and hydrogen evolution reaction(HER)have attracted much consideration due to their high efficiency and no pollution.It is of much concern to fabricate heterogeneous electrocatalysts with high efficiency under simple and easy operating conditions.Up to now,Pt and Pt-based materials,although scarce and expensive,are still the most highly efficient and widely used electrochemical catalysts for FOR and HER.Prepare bimetallic alloy has been proven to be an effective method to improve catalytic efficiency.Introducing a second metal(such as Pd,Co,Ni or Ag)into Pt also make possible less use of platinum.Surface modification and nanoalloying have been recognized as effective methods to control the construction of noble-metal catalysts.However,alloy particles on the surface of catalyst are easy loss and leads to a decrease in stability sequentially.Therefore,a suitable carrier is required to support the metal nanoparticles.There are many kinds of carriers,such as polymers.Polyaniline doped with protonic acid is widely used due to its low price,good electrical conductivity and high stability.In our work,we successfully synthesize of partially crystallized polyaniline(c-PANI)induced PtAg nanoalloy(c-PANI@PtAg)by using a simple and easy method.And it was characterized by SEM,TEM,HRTEM,XRD,UV-Vis,FT-IR,XPS and TGA.The results show that Pt and Ag form nano-alloy spherical particles.c-PANI forms hollow tubulars while the composite has a crosslinked fiber structure with a diameter of about 30 nm.There is no new chemical bond formation between c-PANI and PtAg,only physical interaction,and the embedding of PtAg enhances the conductivity of c-PANI.The ordered c-PANI as electrocatalyst prefers to increase reaction selectivity by controlling the potential of the electrolytic cell.We fabricate PtAg nanomaterial alloy through liquid phase reduction on Pt sheet(PtAg/Pt).Then in-suit growth c-PANI coated on PtAg/Pt for encapsulating the nanoparticles(c-PANI@PtAg/Pt).Further electrocatalysis evaluation of formate oxidation reaction(FOR)shows that c-PANI@PtAg/Pt presents significantly improved catalytic path selectivity and excellent current holding ratio that as bigger as 91.4%after 1000 circles CV scanning.For HERs,all the onset potential and the Tafel slope of c-PANI@Pt1Ag0.5/Pt are both low and the current exchange density is relatively increased in acid.The results show that c-PANI@PtAg/Pt is a dual-functional electrochemical catalyst with excellent performance,which can be used to catalyze FOR and HER.