synthesis of silver nanoparticles on nitrogen doped carbon quantum dots for oxygen reduction reaction and water splitting

The precious metal platinum (pt) catalysts are suffering from some puddles owing to their high cost, dissolution and aggregation[1]. thus, to cut down the amount of pt or develop new catalysts becomes a crucial issue. silver (ag) is believed as a potential candidate to substitute pt in oxygen reduction reaction (orr) and oxygen evolution reaction (oer). except for its abundance and low cost, ag has relatively high orr and oer activity and stability in alkaline electrolyte[2]. however, its performance has been reported to be low[3]. one of promising strategies for further increasing catalytic properties is to prepare a more conductive supporter coupled with some effective nitrogen doped on carbon quantum dot (n-cqds) catalysts [4].we report ag/rn-cqds catalyst for orr in alkaline media. n-cqds were synthesized through hydrothermal method, then silver was reduced by nabh4 and deposited on n-cqds. to further study synthetic catalyst, x-ray crystallography (xrd), fourier-transform infrared spectroscopy (ft-ir), raman spectrometry (raman) and scanning electron microscopy (sem) are used to investigate crystallite size, absorption spectra, carbon structures and the surface morphologies respectively.the electrochemical characteristic of the ag/rn-cqds catalysts are investigated by cyclic voltammetry (cv), linear sweep voltammetry (lsv) and electrochemical impedance spectroscopy (eis) in o2 saturated 0.1 m koh solution. lsv and cv was used to obtain tafel slop and onset potential as shown in figs.1&2.