ZnO复合石墨相氮化碳纳米片的制备及其光催化性能研究

为了提高石墨相氮化碳光催化性能，本文以尿素、硫脲、醋酸锌为前驱体，通过氧化热剥离与共混煅烧法分别制备g-C₃N₄纳米片和ZnO/g-C₃N₄异质结复合材料，并采用TEM、FTIR、XRD、UV-Vis DRS、BET等表征手段对制备的催化剂进行结构表征。以罗丹明、大肠杆菌为探针，考察了催化剂的光催化降解性能和抑菌活性。结果表明：以尿素和硫脲为前驱体，经过氧化热剥离处理后能得到的g-C₃N₄ 2D纳米片，其比表面积更大、光催化性能更加优异，且其对罗丹明的降解率较未剥离的g-C₃N₄提高了21.2%。在40 min氙灯照射下，纯g-C₃N₄并未表现出良好的抑菌性能，而通过ZnO复合制备的ZnO/g-C₃N₄异质结复合材料，在光催化降解率和抑菌活性方面均有很大提高，其中复合20%ZnO制得的ZnO异质结复合材料表现出最佳的光催化性能...

Preparation and photocatalytic properties of ZnO composite graphitic carbon nitride nanosheets

In order to improve the photocatalytic performance of graphite phase carbon nitride, g-C₃N₄ nano-sheet and ZnO/g-C₃N₄ heterojunction composite were prepared using urea, thiourea and zinc acetate as precursors by oxidative thermal stripping and blending calcination, respectively. The structure of the prepared catalyst was characterized by TEM, FTIR, XRD, UV-Vis DRS, BET and other characterization methods. Using Rhodamine and Escherichia coli as probes, the photocatalytic degradation performance and antibacterial activity of the catalyst were investigated. The results showed that the specific surface area of g-C₃N₄ 2D nano-sheets obtained from urea and thiourea as precursors after oxidative thermal stripping treatment was larger, and their photocatalytic performance was better, and their degradation rate of rhodamine was 21.2% higher than that of g-C₃N₄ without stripping. Under 40 min xenon lamp irradiation, pure g-C₃N₄ did not show good bacteriostatic performance, while ZnO/g-C₃N₄ heterojunction composite prepared by ZnO composite showed great improvement in photocatalytic degradation rate and bacteriostatic activity, among which ZnO heterojunction composite prepared by 20%ZnO composite showed the best photocatalytic performance, and under 60 min xenon lamp illumination, the degradation rate of rhodamine solution with a mass concentration of 10 mg/L reached 91.2%. 20%ZnO/g-C₃N₄ showed excellent antibacterial activity against Escherichia coli. After 40 minutes of xenon lamp irradiation, its antibacterial rate against 10⁶ cfu/mL bacterial suspension reached 100%. Graphite phase carbon nitride can increase the specific surface area by oxidative thermal stripping, and then compound with metal oxide ZnO. By reducing the band gap, the utilization range of visible light can be expanded, in order to improve the photocatalytic performance.