Novack Aline M, Dos Reis Glaydson S, Hackbarth Fabíola V, Marinho Belisa A, Ðolić Maja B, Valle José A B, Sampaio Carlos H, Lima Eder C, Dotto Guillherme L, Ulson de Souza Antônio Augusto, Vilar Vítor J P, Guelli Ulson de Souza Selene M A
Laboratory of Mass Transfer, Federal University of Santa Catarina (UFSC), PO Box 476, Florianópolis, SC, 88040-900, Brazil.
Graduate Program in Mine, Metallurgical, and Materials Engineering (PPGE3M), School of Engineering, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Porto Alegre, RS, Brazil.
Environ Sci Pollut Res Int. 2021 May;28(19):23568-23581. doi: 10.1007/s11356-020-09178-1. Epub 2020 May 30.
This paper presents the synthesis of a hybrid material through the use of natural pozzolan and titanium(IV) isopropoxide using the sol-gel method and its application in the photocatalytic hexavalent chromium reduction. The characterization data indicated a mesoporous material possessing a surface area of 271.7 m g. The morphology studies (SEM and TEM) showed nanosheet hybrid structures. The analysis of DRUV, FTIR, XRD, and Mössbauer spectroscopy provides a different electronic structure of the synthetized material when compared with the originals, proving the hybridization process between pozzolan and titanium(IV) isopropoxide. The photocatalytic reduction of Cr(VI) to Cr(III) using the hybrid material showed a better performance than conventional photocatalysts (precursor and TiO-P25). Operational conditions such as chromium initial concentration (0.02-0.20 mM), solution pH (3-6), and type of scavenger (citric or tartaric acid) were evaluated in order to determine the best experimental conditions for the Cr(VI) photoreduction. At their optimum (catalyst load of 15 mg L, tartaric acid as scavenger, [scavenger]/[Cr(VI)] M ratio = 3:1, pH 3, and 25 °C), the total photoreduction of 0.20 mM Cr(VI) was achieved in 180 min. The novel hybrid materials synthesized from pozzolan and titanium(IV) isopropoxide showed to be a potential catalyst for the Cr(VI) reduction in aqueous solution. Graphical abstract.
本文介绍了通过溶胶-凝胶法使用天然火山灰和异丙醇钛(IV)合成一种混合材料及其在光催化还原六价铬中的应用。表征数据表明该材料为介孔材料，比表面积为271.7 m²/g。形态学研究（扫描电子显微镜和透射电子显微镜）显示为纳米片混合结构。与原始材料相比，漫反射紫外可见光谱、傅里叶变换红外光谱、X射线衍射和穆斯堡尔光谱分析表明合成材料具有不同的电子结构，证明了火山灰与异丙醇钛(IV)之间的杂化过程。使用该混合材料将Cr(VI)光催化还原为Cr(III)的性能优于传统光催化剂（前驱体和TiO-P25）。评估了诸如铬初始浓度(0.02 - 0.20 mM)、溶液pH值(3 - 6)和清除剂类型（柠檬酸或酒石酸）等操作条件，以确定Cr(VI)光还原的最佳实验条件。在最佳条件下（催化剂负载量为15 mg/L，酒石酸作为清除剂，[清除剂]/[Cr(VI)]摩尔比 = 3:1，pH 3，25°C），180分钟内实现了0.20 mM Cr(VI)的完全光还原。由火山灰和异丙醇钛(IV)合成的新型混合材料显示出是水溶液中Cr(VI)还原的潜在催化剂。图形摘要。
