Cobalt molybdate(CoMoO4)is prepared via precipitation method,and then used to prepare cobalt molybdenum sulfide(CoMoS4)through an ion exchange method.The prepared CoMoS4 is characterized by means of XRD,SEM and XPS.Cyclic voltammetry and differential pulse voltammetry are utilized to investigate the electrochemical detection performance of CoMoS4 modified electrode for ascorbic acid.The results show that the response current(Ip)exhibits a good linear relationship with ascorbic acid molar concentration(c)when a phosphoric acid buffer with a pH of 6 is used as the electrolyte,the molar concentration of ascorbic acid ranges from 0 mmol·L-1 to 10 mmol·L-1 and the applied voltage ranges from-2.0 V to 1.0 V.The linear regression equation is Ip=-116.05c+717.99,R2=0.960 3,and the detection limit is 0.001 mmol-L-1.MS software is employed to simulate ascorbic acid molecule,and calculate the electro-negativity and electron cloud distribution.Combined with the results by infrared spectrum analysis,the oxidation mechanism is speculated as follows:The hydroxyl groups of ascorbic acid have undergone a chemical reaction and been converted into keto groups.It is indicated through the repeated experiments that the CoMoS4-modified glassy carbon electrode has higher reproducibility and better anti-interference.
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