CQDs/TiO_(2)二元复合材料的制备及光催化性能研究

Preparation and photocatalytic properties of CQDs/TiO_(2)binary composites

以柠檬酸、硫脲、尿素等廉价易得的药品为原料,采用水热法制备了3种不同荧光性能的碳量子点CQDs(绿色荧光碳量子点GCQDs、蓝色荧光碳量子点BCQDs、红色荧光碳量子点RCQDs);同时采用溶胶-凝胶法制备了纳米TiO_(2),然后通过物理法制备了3种二元复合光催化剂GCQDs/TiO_(2)、BCQDs/TiO_(2)、RCQDs/TiO_(2)。采用FTIR、PL、XRD、BET等表征方法对产品进行了结构性能表征。通过紫外光谱分析,探究了TiO_(2)和3种二元复合材料对次甲基蓝溶液的催化降解性能。光催化实验结果表明,纳米TiO_(2)在日光照射下10min对次甲基蓝的降解率为42.2%;GCQDs/TiO_(2)、BCQDs/TiO_(2)、RCQDs/TiO_(2)在日光照射下10min对次甲基蓝溶液的降解率分别为73.13%、46.82%、50.82%;3种二元复合材料的催化降解性能均优于纯TiO_(2),其中GCQDs/TiO_(2)催化降解性能最优异。

Three kinds of carbon quantum dots CQDs(green fluorescent carbon quantum dots GCQDs,blue fluorescent carbon quantum dots BCQDs,red fluorescent carbon quantum dots RCQDs)with different fluorescence properties were prepared by hydrothermal method using cheap and readily available drugs such as citric acid,thiourea and urea as raw materials.At the same time,nano-TiO_(2)was prepared by sol-gel method,and then three binary composite photocatalysts GCQDs/TiO_(2),BCQDs/TiO_(2)and RCQDs/TiO_(2)were prepared by physical method.The structure and properties of CQDs and CQDs/TiO_(2)were characterized by FTIR,PL,XRD and BET.The catalytic degradation performance of TiO_(2)and CQDs/TiO_(2)on methylene blue solution was investigated by ultraviolet spectrum analysis.The results of photocatalytic experiments showed that the degradation rate of methylene blue by nano-TiO_(2)is 42.2%in 10 minutes under sunlight.The degradation rates of methylene blue solution by GCQDs/TiO_(2),BCQDs/TiO_(2)and RCQDs/TiO_(2)under sunlight for 10 minutes were 73.13%,46.82%and 50.82%,respectively.The catalytic degradation performance of CQDs/TiO_(2)was better than that of TiO_(2),and the catalytic degradation performance of GCQDs/TiO_(2)was the best.