混晶纳米二氧化钛乳液光催化降解农药的研究

为了降解农药废水,以混晶纳米TiO2乳液为催化剂,以太阳光为光源,对降解农药模拟废水进行了系统研究.结果表明:降解体系的pH值、催化剂和农药质量浓度、光源辐照时间等因素对乳液光催化降解农药有一定影响,反应动力学研究表明此降解反应是一级反应(K=0.014 35 min-1).

负载型TiO_2/ACF光催化剂的制备及同时脱硫脱硝实验研究

选用活性炭纤维(ACF)为载体,浸渍提拉法制备出负载型TiO2/ACF光催化剂,采用扫描电镜(SEM)、X-射线能谱(EDS)等分析手段,对薄膜的表面形貌和成分进行了分析。研究了浸渍时间、浸渍液浓度和浸涂次数对TiO2负载量的影响,发现影响TiO2负载量的主要因素是浸渍液浓度和浸涂次数,而浸渍时间对负载量的影响不明显。利用该催化剂进行了光催化同时脱除SO2和NO实验,在最佳实验条件下,SO2脱除效率为97.5%,NO脱除效率为49.6%。

TiO_2/ACF催化剂的制备、表征及对水中甲基橙的降解

以TiCL4、氨水、吐温80为主要原料,分步水解法制备出混晶纳米二氧化钛分散乳液,采用XRD、TEM等分析手段,对乳液的物相、形貌进行了表征。选用活性炭纤维(ACF)为载体,浸渍提拉法制备出混晶型TiO2/ACF光催化剂,采用SEM,EDS等分析手段,对薄膜的表面形貌和成分进行了分析。在可见光下研究了影响甲基橙降解效率的因素,结果表明,在最佳实验条件下,日光照射30 min后对甲基橙溶液的降解率为94.6%,混晶纳米二氧化钛在可见光下的光催化活性明显。

Preparation of amphiphilic TiO_2 Janus particles with highly enhanced photocatalytic activity

Stearic-acid-modified TiO2 (STA-TiO2) particles were prepared via the impregnation approach and used as a precursor for preparing TiO2 Janus particles. The morphology, structure, and properties of the TiO2 Janus particles were characterized using Fourier-transform infrared spectroscopy, ultraviolet- visible diffuse reflectance spectroscopy, thermogravimetric analysis, fluorescence microscopy, high-resolution transmission electron microscopy, contact angle analysis, dynamic light scattering, biological microscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy measurements. The results show that TiO2 Janus particles can be successfully prepared via toposelective surface modification. STA grafted on the surface of TiO2 enhances its hydrophobicity, promotes charge separation, and improves its adsorption capacity for organic compounds. The TiO2 Janus particles strongly adsorb on an oil-water interface to form a stable Pickering emulsion. The degradation rates of high-concentration kerosene and nitrobenzene wastewaters when the photocatalyst is pure TiO2, STA-TiO2, or TiO2 Janus particles are discussed and compared. The degradation rates were determined using an ultraviolet-visible spectrophotometer. It was found that the Pickering emulsion stabilized by the TiO2 Janus particles exhibited the best photocatalytic performance;these Janus particles show promising potential for catalytic application.