| What the target of this paper is that we want to find the methods which can be used efficiently and low-costly to restore the CO2, what’s more, we also want to build several interface which is activity in restoring the CO2. In this paper, we utilized some methods, such as electro-chemistry,to restore the CO2. Above all,we used the gold cluster (Au25) which have efficient activity as a catalyst in reduction of CO2 to build four activity interface that can be used to CO2 efficiently and low-costly. They are gold cluster (Au25) modified glass carbon electrodes, gold cluster (Au25) modified Au electrode,2-Pyrazinylethanethiol nanometer-gold cluster (Au25) modified glass carbon electrode and 2-Pyrazinylethanethiol nanometer-gold cluster (Au25) modified Au electrode. We utilized cyclic voltammetry (CV), transmission electron microscope (TEM), electrochemical impedance spectroscopy(EIS), in-situ ftir spectroelectrochemistry (FT-IR), ultraviolet spectrophotometer(UV) and other analysis and determination methods studied the reduction of CO2 on these four activity interface. Especially the over potential of them. In the end, we discuss the reaction mechanism of carbon dioxide on these interface. We can make a summary as follows.1. The reduction of CO2 on gold cluster (Au25) modified glass carbon electrode.At the beginning, we used double-phase method which is mature for a long time to synthesis ngold cluster (Au25). After the synthesis, the production was characterized by ultraviolet spectrophotometer(UV) and transmission electron microscope (TEM).Then, we prepare nanometer-gold cluster (Au25) modified glass carbon electrode through the adsorption from the glass carbon electrode and gold cluster (Au25). After that,the new prepared nanometer-gold cluster (Au25) modified glass carbon electrode was characterized by electrochemical impedance spectroscopy(EIS).The result of electrochemical impedance spectroscopy(EIS) suggest that gold cluster (Au25) modified glass carbon electrode were well prepared. We utilized Cyclic voltammetry and IR spectroelectrochemistry to study the reduction of CO2 on gold cluster (Au25) modified glass carbon electrode, and we perform several control experiment,such as the gold cluster (Au25) modified glass carbon electrode in blank solution acetonitrile+TBAP (0.15 mol·L-1) which is without carbon dioxide and blank glass carbon electrode in acetonitrile +TBAP (0.15 mol·L-1) with CO2.In the Cyclic Voltammetry experiment, we set the volt scandal range from 0 V to-2.4 V and we can see the peak of the reduction of CO2 at-2.1V. In contrast, there was no peak in this position when we used glass carbon electrode. This phenomenon suggest that the reduction of CO2 on glass carbon electrode had lower faraday current that we can’t see the peak apparently compared with the gold cluster (Au25) modified glass carbon electrode. In conclusion, gold cluster (Au2s) modified glass carbon electrode show that it can be catalyze at the reduction of carbon dioxide and we successfully prepared the interface at the reduction of CO2.When it comes to the in situ infrared difference spectrum, we studied the change of several infrared characteristic peak include O2 (2340 cm-1), CO2" (1650 cm-1), C=O (1670 cm-1), C2O42- (1250 cm-1), CO32-(1375 cm-1) and C—O (1100 cm-1).Combined with the result of in situ infrared difference spectrum and Cyclic Voltammetry, we can make a conclusion that gold cluster (Au25) change the reduction mechanism of CO2 that at the glass carbon electrode, because it not only decrease the over potential of the reduction of CO2 but also increase the faraday current of the reaction. In a word, the gold cluster (Au25) modified glass carbon electrode is a good interface at the reduction of carbon dioxide because it can complete the reduction of CO2 efficiently and low-costly.2. The electro-catalysis reduction of CO2 on self-assembly gold cluster (Au25) modified Au electrode.We used the gold cluster (Au25) through the method of self-assembly to modified the Au electrode. In our experiment, self-assembly method made the gold cluster (Au2s) modified electrode uniformity and stability because it can make full use of the Au-S bond between gold cluster (Au25) and Au electrode.According to the Cyclic Voltammetry curve,we can safely draw a conclusion that gold cluster (Au25) modified Au electrode decrease the over potential of the reduction of CO2 about 100 m V, in other words,we may cost less energy when we restore the CO2. Meanwhile, from the Cyclic Voltammetry curve, we can find the reduction of CO2 appear twice because the double reduction current peak and the second peak decrease 150 mV than the first peak. These can state that the gold cluster (Au2s) modified Au electrode is a good electro-catalytic reduction interface. In situ infrared difference spectrum, we study the reduction mechanism of carbon dioxide on gold cluster (Au25)modified Au electrode. We discussed the infrared peak of 1100cm-1、2343cm-1、 1370cm-1、1515cm-1、1645cm-1 and 2115cm-1.The analytical result suggests that nanometer-gold cluster (Au25) change the reaction mechanism of carbon dioxide on Au electrode. The reduction of CO2 on nanometer-gold cluster (Au25) modified Au electrode become more efficient and lower-costly.3. The electro-catalysis reduction of CO2 on 2-Pyrazinylethanethiol modified nanometer-gold cluster (Au25) modified glass carbon electrode and Au electrode.(1) The electro-catalysis reduction of CO2 on 2-Pyrazinylethanethiol modified gold cluster (Au25) modified glass carbon electrode.We select 2-Pyrazinylethanethiol as our electro-catalysis materials to modified prepared nanometer-gold cluster (Au25) modified glass carbon to build a new electro-catalysis interface. Combined the in situ infrared difference spectrum result and Cyclic Voltammetry curve, we may easily draw a conclusion that 2-Pyrazinylethanethiol gold cluster (Au25) modified glass carbon electrode decrease the over potential in the reduction of carbon dioxide from -2.1 V to-1.85 V. There are nearly 250 mV lower than the gold cluster (Au25) modified glass carbon electrode in reduction of CO2, in other words,2-Pyrazinylethanethiol is a more activity electro-catalysis when it is used to the reduction of CO2. Above all, we successfully get another efficiently and lower-costly electro-catalysis in the reduction of CO2.(2) The electro-catalysis reduction of CO2 on 2-Pyrazinylethanethiol modified nanometer-gold cluster (Au25) modified Au electrode.After analyzed the experiment result, we found that 2-Pyrazinylethanethiol modified gold cluster (Au25) modified Au electrode has a little catalytic activity in reduction of CO2, because it highly improves the faraday current but raise the potential at the same time. |
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