负载TiO2/WO3粉煤灰分子筛表征及对水中高浓度活性红X-3b光催化性能

用水热合成法将热电固废粉煤灰制备成分子筛F,将其作为材料基板,用浸渍法分别负载TiO_2/WO_3,制成粉煤灰分子筛光催化剂Ti/F、W/F、W&Ti/F。通过SEM-EDS、XRD和BET对4种材料作表征,研究催化剂光催化去除水中高浓度活性红X-3b效果及反应动力学特性。结果表明,F中含Ti不含W,Ti主要以金红石型TiO_2单晶存在。与F相比,Ti/F新增TiO_2晶型为钛锐型TiO_2,Ti以锐钛型和金红石型混晶存在;F负载WO_3改变表面结构,平均孔径增加,活性红吸附率增加,W取代F中金红石型Ti明显降低Ti含量;W&Ti/F的Ti、W双负载(0.5:0.5)使Ti和W负载量分别高于Ti/F和W/F,但锐钛型和金红石型混晶TiO_2量明显低于Ti/F,光催化活性低于Ti/F。Ti/F、W/F、W&Ti/F、F均对水中高浓度活性红X-3b具有光催化活性。催化活性成分主要为锐钛型和金红石型TiO_2。Ti/F光催化效果最好;在最优条件下,紫外光照630 min,2 000 mg·L~(-1)活性红X-3b去除率为95.74%;其次为F,93.83%;W&Ti/F和W/F去除率分别为87.78%和87.60%。光催化反应20℃下符合一级动力学反应,40℃下符合二级动力学反应。Ti/F和F分子筛对2 000 mg·L~(-1)活性红X-3b具有高光催化活性,使光催化处理活性红X-3b浓度范围显著提高。

Characterization of fly ash molecular sieves loaded with TiO_2/WO_3 and their photocatalytic performance to reactive red X-3b in water

In this experiment, thermoelectric solid waste fly ash was prepared into molecular sieve F by hydrothermal synthesis method. F was used as carbon material substrate, and photocatalysts loaded with TiO_2/WO_3 such as Ti/F, W/F, W&Ti/F were respectively prepared by general impregnation method. The photocatalysts Ti/F, F, W/F, W&Ti/F were characterized by SEM-EDS, XRD, and BET, and the photocatalytic removal effect of high concentration Reactive Red X-3 b in water by various catalysts and the reaction kinetics characteristics were studied. The results showed that F contained Ti but not W and Ti was mainly rutile type single crystal TiO_2. Compared with F, the crystal type of TiO_2 added in Ti/F was anatase type TiO_2, Ti existed in anatase and rutile mixed crystals. F Loading WO_3 changed the surface structure and the average pore size increased, and the adsorption rate of Reactive Red increased. W replaced rutile Ti in F, so that Ti content decreased significantly. The Ti and W double loads(0.5:0.5) of W&Ti/F made Ti and W content higher than Ti/F and W/F, respectively, but the amount of anatase and rutile mixed crystals TiO_2 was significantly lower than Ti/F, so that the photocatalytic activity was lower than Ti/F. Ti/F, W/F, W&Ti/F, F had photocatalytic activity for high concentration Reactive Red X-3b in water. The catalytically active components were mainly anatase type and rutile type TiO_2. Ti/F had the best photocatalytic effect. Under the optimum conditions, the ultraviolet light irradiation for 630 min, the removal rate of 2 000 mg · L~(-1) Reactive Red X-3 b was as high as 95.74%, followed by F, 93.83%. The removal rate of W&Ti/F and W/F were similar, 87.78% and87.60% respectively. The photocatalytic reaction was a first-order kinetic reaction at 20 ℃ and a secondorder kinetic reaction at 40 ℃. Ti/F and F molecular sieves had high photocatalytic activity for 2 000 mg·L~(-1) Reactive Red X-3 b, so that the concentration range of photocatalytic treatment of Reactive Red X-3 b was greatly improved.