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

Characterization of fly ash molecular sieves loaded with TiO2/WO3 and their photocatalytic performance to reactive red X-3b in water

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TiO2/WO3,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TiO2单晶存在。与F相比,Ti/F新增TiO2晶型为钛锐型TiO2,Ti以锐钛型和金红石型混晶存在;F负载WO3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TiO2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TiO2。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。

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 TiO2/WO3 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-3b 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 TiO2.Compared with F,the crystal type of TiO2 added in Ti/F was anatase type TiO2,Ti existed in anatase and rutile mixed crystals.F Loading WO3 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 TiO2 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 TiO2.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-3b 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%and 87.60%respectively.The photocatalytic reaction was a first-order kinetic reaction at 20℃and a second-order kinetic reaction at 40℃.Ti/F and F molecular sieves had high photocatalytic activity for 2 000 mg·L^-1 Reactive Red X-3b,so that the concentration range of photocatalytic treatment of Reactive Red X-3b was greatly improved.