以硝酸银为银源、次磷酸钠为磷源、双氢胺为氮化碳前驱体,制备了磷银共掺杂氮化碳(P/Ag-CN)。通过X射线衍射、扫描电镜(SEM)、紫外-可见光分光光度计、荧光光谱、BET对样品进行了结构表征,通过光催化降解亚甲基蓝对其进行了光催化性能分析。结果表明:通过元素掺杂有效地改善了直接热缩聚法所得氮化碳比表面积小、光生电子-空穴复合率高的缺陷。与纯g-C3N4相比,P/Ag-CN的形貌由紧密堆积的层状结构转变为类似棉花糖的疏松结构,同时展示出更高的比表面积和更优异的光催化性能。当Ag掺杂量为2.5%、P掺杂量为3.0%时,银磷共掺杂g-C3N4的光催化性能最优,可达90.02%,其一阶反应速率常数分别是同等掺杂量时单掺杂样品的5.6倍和3.5倍,是纯g-C3N4的7.62倍。
In this study,silver phosphate co-doped carbon nitride (P/Ag-CN) was prepared by using silver nitrate as silver source,sodium hypophosphate as phosphorus source and dihydroamine as carbon nitride precursor.The results showed that the defects of small specific surface area and high photoelectron-hole recombination rate of carbon nitride obtained by direct thermo condensation were effectively improved by element doping.The structures of the samples were characterized by XRD,SEM,UV-Vis and PL spectra,and the photocatalytic properties of the samples were also analyzed by photocatalytic degradation of methylene blue.The results indicated that,compared with pure g-C3N4,the morphology of Ag/P-CN changed from tightly packed layered structure to loose structure similar to cotton candy,and exhibited higher specific surface area and better photocatalytic performance.When the doping amount of Ag was 2.5wt% and the doping amount of P was 3.0wt%,the photocatalytic performance of P/Ag-CN was the best,reaching 90.02%.The first-order reaction rate constants of Ag/P-CN were 5.6 and 3.5 times of that of single doped sample under the same doping condition,and 7.62 times of that of pure g-C3N4.
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基金资助
国家自然科学基金(31960297、31660179和31960296)云南省省级大学生创新创业训练计划项目(20191364001)
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