Gembo Robert O, Aoyi Ochieng, Majoni Stephen, Etale Anita, Odisitse Sebusi, King'ondu Cecil K
Department of Chemical and Forensic Sciences, Botswana International University of Science and Technology, Palapye, Botswana.
Department of Chemical, Materials, and Metallurgical Engineering, Botswana International University of Science and Technology, Palapye, Botswana.
AAS Open Res. 2022 Feb 4;4:43. doi: 10.12688/aasopenres.13249.2. eCollection 2021.
The removal of textile wastes is a priority due to their mutagenic and carcinogenic properties. In this study, bismuth oxyhalide was used in the removal of methylene blue (MB) which is a textile waste. The main objective of this study was to develop and investigate the applicability of a bismuth oxyhalide (BiOBr I ) solid solutions in the photodegradation of MB under solar and ultraviolet (UV) light irradiation. Bismuth oxyhalide BiOBr I ) (0 ≤ z ≤ 1) materials were successfully prepared through the hydrothermal method. Brunauer-Emmett-Teller (BET), transmission electron microscope (TEM), X-ray diffractometer (XRD), and scanning electron microscope (SEM) were used to determine the surface area, microstructure, crystal structure, and morphology of the resultant products. The photocatalytic performance of BiOBr I materials was examined through methylene blue (MB) degradation under UV light and solar irradiation. The XRD showed that BiOBr I materials crystallized into a tetragonal crystal structure with (102) peak slightly shifting to lower diffraction angle with an increase in the amount of iodide (I ). BiOBr I materials showed a point of zero charge of 5.29 and presented the highest photocatalytic activity in the removal of MB with 99% and 88% efficiency under solar and UV irradiation, respectively. The kinetics studies of MB removal by BiOBr I materials showed that the degradation process followed nonlinear pseudo-first-order model indicating that the removal of MB depends on the population of the adsorption sites. Trapping experiments confirmed that photogenerated holes (h ) and superoxide radicals ( O ) are the key species responsible for the degradation of MB. This study shows that bismuth oxyhalide materials are very active in the degradation of methylene blue dye using sunlight and thus they have great potential in safeguarding public health and the environment from the dye's degradation standpoint. Moreover, the experimental results agree with nonlinear fitting.
由于纺织废料具有致突变性和致癌性，因此去除纺织废料是当务之急。在本研究中，卤氧化铋被用于去除作为纺织废料的亚甲基蓝（MB）。本研究的主要目的是开发并研究卤氧化铋（BiOBrI）固溶体在太阳光和紫外（UV）光照射下对MB光降解的适用性。通过水热法成功制备了卤氧化铋BiOBrI（0≤z≤1）材料。使用布鲁诺尔-埃米特-泰勒（BET）法、透射电子显微镜（TEM）、X射线衍射仪（XRD）和扫描电子显微镜（SEM）来确定所得产物的表面积、微观结构、晶体结构和形态。通过在紫外光和太阳光照射下亚甲基蓝（MB）的降解来考察BiOBrI材料的光催化性能。XRD表明，BiOBrI材料结晶为四方晶体结构，随着碘化物（I）含量的增加，（102）峰向较低衍射角略有偏移。BiOBrI材料的零电荷点为5.29，在去除MB方面表现出最高的光催化活性，在太阳光和紫外光照射下的效率分别为99%和88%。BiOBrI材料去除MB的动力学研究表明，降解过程遵循非线性准一级模型，这表明MB的去除取决于吸附位点的数量。捕获实验证实，光生空穴（h）和超氧自由基（O）是导致MB降解的关键物种。本研究表明，从染料降解的角度来看，卤氧化铋材料在利用太阳光降解亚甲基蓝染料方面非常活跃，因此在保障公众健康和环境方面具有巨大潜力。此外，实验结果与非线性拟合结果相符。
