磷掺杂g-C_(3)N_(4)纳米片光催化降解盐酸四环素

Photocatalytic degradation of tetracycline hydrochloride by phosphorus-doped g-C_(3)N_(4) nanosheets

针对无金属g-C_(3)N_(4)基光催化材料光激发载流子的快速复合限制了其光催化活性的问题,以双氰胺和羟基乙叉二膦酸(HEDP)为前驱体,结合形貌调控和磷掺杂两种改性方法,制备了不同磷(P)掺杂量的石墨相氮化碳(g-C_(3)N_(4))纳米片(PCNNS),对其形貌结构和光学性质进行了表征分析,并研究了降解盐酸四环素(TCH)的光催化性能和降解机理。结果表明:PCNNS-0.5降解速率最高,为块体g-C_(3)N_(4)(BCN)的2.52倍,降解动力学均符合伪一级反应动力学模型;·O^(-)_(2)和h^(+)是降解过程中的主要活性物种;经过4次循环实验,PCNNS-0.5仍具有较高的稳定性和良好的性能。PCNNS良好的光催化性能归因于P原子取代g-C_(3)N_(4)中碳原子所产生的良好的结构、光学和电子性质。

Metal-free g-C_(3)N_(4) based photocatalytic materials are widely used for the degradation of antibioticwastewater due to their non-toxic and non-hazardous nature, stable chemical structure and low cost. However,the rapid compounding of their photoexcited carriers limit their photocatalytic activity. In this study, combiningmorphology modulation and phosphorus doping two modification methods, graphite-phase carbon nitride(g-C_(3)N_(4)) nanosheets(PCNNS) with different phosphorus(P) doping amounts are prepared using dicyandiamideand hydroxyethylidene diphosphonic acid(HEDP) as the precursors. The morphological structure and opticalproperties are characterized, and the photocatalytic performance and degradation mechanism of tetracyclinehydrochloride(TCH) are investigated. The results show that the degradation rate of PCNNS-0. 5 is the highest,which is 2. 52 times of that of bulk graphitic phase carbon nitride(BCN), and the degradation kinetics are allconsistent with a pseudo primary reaction kinetic model;·O^(-)_(2) and h^(+) are the main active species in the degradationprocess;after four cycles of experiments, PCNNS-0. 5 still has high stability and good performance. Thegood photocatalytic performance of PCNNS is attributed to the good structural, optical and electronic propertiesresulting from the substitution of phosphorus atoms for carbon atoms in g-C_(3)N_(4).