| Nanomaterials made of a transition metal core and platinum shell are widely used in the field of fuel cells,solar cells and electrochemical sensors,due to their superior electrocatalytic activity.In this paper,M@Pt/C(M = Fe,Co,Ni,Cu)core-shell nanocomposites were synthetized by two-step chemical reduction method and applied to construct of nonenzymatic electrochemical sensors.The sensors based on M@Pt/C were used to detect glucose,hydrogen peroxide and dopamine,showing high sensitivity,fast response speed,excellent selectivity,and they could be used in practical application.Compared with nonenzymatic electrochemical sensors based on Pt/C,the sensors based on M@Pt/C showed superior electrocatalytic ability,wider linear range,lower detection limit,better anti-interference ability.Besides,they could reduce the usage of the platinum and improve the utilization rate of platinum.At the same time,the Fe@Pt/C core-shell nanocomposites were used as electrocatalyst for oxygen reduction reaction at cathode of hydrogen-oxygen fuel cells,and their electrocatalytic activity and stability were better than that of Pt/C.The main contents and results are summarized as follows:(1)The controllable synthesis of Fe@Pt/C core-shell nanocomposites and their applicationsFe@Pt/C core-shell nanocomposites were synthetized by spontaneous replacement reaction,using iron(?)sulfate heptahydrate(FeSO4·7H2O)and dipotassium tetrachloroplatinate(K2PtCl4)as precursors.They were applied to construct of nonenzymatic electrochemical sensors.The composition and morphology of the Fe@Pt/C nanocomposites were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy,and transmission electron microscopy.The results indicated that the Fe@Pt nanoparticles present the face centered cubic phase of platinum,and the particle size was about 5 nm with high dispersion.The results of the electrochemical testings indicated that the sensors had wider linear range,high sensitivity,lower detection limit,better selectivity,excellent stability and reproducibility for detection of hydrogen peroxide and glucose.The sensors based on Fe@Pt/C could be used to detect the concentration of glucose in human serum samples,hydrogen peroxide in lake water and hydrogen peroxide antibacterial lotion(3%).Besides,the Fe@Pt/C core-shell nanocomposites were used as electrocatalysts for oxygen reduction reaction at cathode of hydrogen-oxygen fuel cells,and the results was also good.(2)The synthesis of Co@Pt/C core-shell nanocomposites and their application in nonenzymatic glucose sensorCo@Pt/C core-shell nanocomposites were synthetized by two-step chemical reduction method and they were applied to construct of nonenzymatic glucose sensor.The results of the electrochemical testings indicated that the Co@Pt/C nanocomposites showed better electrocatalytic activity than that of Pt/C.When they were used to detect the concentration of glucose,the best working potential was-0.05 V,the linear range was 1.00-30.00 mM,the limit of detection was 0.30 mM.Besides,they showed high anti-interference ability and they could be used to measure the glucose in real samples.(3)The synthesis of Ni@Pt/C core-shell nanocomposites and their application in nonenzymatic glucose sensorNi@Pt/C core-shell nanocomposites were synthesized by a successive reduction approach and they showed better electrocatalytic activity than that of Pt/C.When they were used to detect the concentration of glucose,the linear range was 0.10-30.10 mM,the sensitivity was 66.9 ?A mM-1 cm-2,the limit of detection was 30.00 ?M with good selectivity.(4)The synthesis of Cu@Pt/C core-shell nanocomposites and their application in nonenzymatic electrochemical sensorsCu@Pt/C core-shell nanocomposites were synthesized by a two-step reduction method,and the morphology,composition,size and electrocatalytic performance were evaluated.The results indicated that the electrocatalytic activities of Cu@Pt/C towards hydrogen peroxide and dopamine were better than that of Pt/C.When they were used to detect dopamine and hydrogen peroxide,they could overcome the interferences of AA and UA. |
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