硫掺杂强化铜基氮化碳材料电催化还原CO_(2)

Enhancement of electrocatalytic reduction of carbon dioxide by sulfur doping in to a copper-based carbon nitride material

制备了硫掺杂铜基氮化碳(CuSx-C_(3)N_(4))催化材料,运用SEM、EDS、TEM、XRD、XPS等技术对其进行了表征,并将其用于以CO为目标产物的电催化CO_(2)还原反应(CO_(2)RR),采用CO法拉第效率和分电流密度分别表征催化材料的CO选择性和催化活性。结果表明:硫掺杂提高了Cu-C_(3)N_(4)材料的CO选择性和催化活性;在掺硫量为1.5%、电位为-0.65 V(相对于可逆氢电极)的最佳条件下,CuSx-C_(3)N_(4)材料的CO选择性最高,CO法拉第效率高达90%;吡啶N比石墨N更易催化CO_(2)RR生成CO,硫掺杂提高了催化材料中吡啶N的占比;相对于Cu-C_(3)N_(4)材料,掺硫量为1.5%的CuSx-C_(3)N_(4)材料中吡啶N占比从22%升至35%,石墨N占比从15%降至12%。

In this study,the CuSx-C_(3)N_(4)catalyst was prepared and characterized by SEM,EDS,TEM,XRD,and XPS.Then,the catalyst was used for the electrocatalytic reduction reaction of CO_(2)(CO_(2)RR)with CO as the target product.Faraday efficiency and partial current density were used to characterize the CO selectivity and catalytic activity of the CuSx-C_(3)N_(4)catalyst,respectively.The results show that sulfur doping improves the CO selectivity and catalytic activity of the Cu-C_(3)N_(4)catalyst.When the sulfur content is 1.5%,and the potential is-0.65 V(relative to the reversible hydrogen electrode),the CO selectivity of the CuSx-C_(3)N_(4)catalyst achieves the highest,and the Faraday efficiency of CO is as high as 90%.Pyridine N is easier to catalyze CO_(2)RR to produce CO than graphite N,and sulfur doping increases the proportion of pyridine N in the catalyst.Compared with the Cu-C_(3)N_(4)catalyst,the proportion of pyridine N in the CuSx-C_(3)N_(4)catalyst with a sulfur content of 1.5%increases from 22%to 35%,and the proportion of graphite N decreases from 15%to 12%.