酸浸浓度对高钛酸浸渣光催化活性的影响

摘要

以低浓度硫酸、高钛渣为原料，采用高能球磨复合水热法，在不同酸浸浓度下合成高钛酸浸渣(ALHTS)光催化剂。利用X射线荧光光谱(XRF)、X射线衍射(XRD)、傅立叶红外(FTIR)、扫描电镜(SEM)、氮气吸附−脱附等温线、差热−热重(TG−DTA)、紫外可见漫反射光谱(DRS)和光致发光谱(PL)分析等对ALHTS催化剂的结构和性能进行分析和表征。在不同酸浸浓度下，通过甲基橙的脱色率来评价ALHTS催化剂的光催化活性。结果表明：当酸浸浓度为20%时，由于钙钛矿含量较高，ALHTS 催化剂的硫酸钙含量较低，BET 的比表面积最大，在紫外−可见区域的光吸收能力最大，电子−空穴对具有较低的再复合率。因此，ALHTS催化剂有较高的光催化活性。采用汞灯光照30 min，不调pH时甲基橙废水脱色率达到87.03%。%Acid leaching of high titanium slag (ALHTS) photocatalysts under different acid concentrations were prepared by the high energy ball milling method combining with hydrothermal method using high titanium slag and dilute sulphuric acid as the starting materials. The structure and performance of ALHTS photocatalysts were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), N 2 adsorption−desorption isotherms, TG−DTA, diffuse reflectance spectrophotometry (DRS) and photoluminescence (PL) methods. The photocatalytic activity of ALHTS photocatalysts under different acidconcentrations was checked by the photocatalytic oxidation of methyl orange as a model compound under UV-vis light irradiation. The results show that, ALHTS catalysts acid leached by 20%sulphuric acid exhibit the highest photocatalytic activity, which can be attributed to the synergic effect of higher content of perovskite, the largest BET specific surface area and UV-visible absorption capacity, and the lower recombination rate of the electron−hole pairs. The decoloration rate of methyl orange without adjusting pH reaches 87.3%under mercury lamp irradiation for 30 min.