Institute of Chemistry, São Paulo State University, 14800-060 Araraquara, SP, Brazil.
Institute of Chemical Sciences, University of Peshawar, PO Box 25120, Peshawar, Pakistan.
ACS Appl Mater Interfaces. 2020 Sep 16;12(37):41627-41643. doi: 10.1021/acsami.0c14137. Epub 2020 Sep 1.
To address the problems associated with the use of unsupported nanomaterials, in general, and molybdenum disulfide (MoS), in particular, we report the preparation of self-supported hybrid aerogel membranes that combine the mechanical stability and excellent textural properties of bacterial nanocellulose (BC)-based organic macro/mesoporous scaffolds with the excellent adsorption-cum-photocatalytic properties and high contaminant removal performance of MoS nanostructures. A controlled hydrothermal growth and precise tuning of the synthetic parameters allowed us to obtain BC/MoS-based porous, self-supported, and stable hybrid aerogels with a unique morphology resulting from a molecular precision in the coating of quantum-confined photocatalytic MoS nanostructures (2-4 nm crystallite size) on BC nanofibrils. These BC/MoS samples exhibit high surface area (97-137 m·g) and pore volume (0.28-0.36 cm·g) and controlled interlayer distances (0.62-1.05 nm) in the MoS nanostructures. Modification of BC with nanostructured MoS led to an enhanced pollutants removal efficiency of the hybrid aerogels both by adsorptive and photocatalytic mechanisms, as indicated by a detailed study using a specifically designed membrane photoreactor containing the developed photoactive/adsorptive BC/MoS hybrid membranes. Most importantly, the prepared BC/MoS aerogel membranes showed high performance in the photoassisted removal of both organic dye (methylene blue (MB)) molecules (96% removal within 120 min, = 0.0267 min) and heavy metal ions (88% Cr(VI) removal within 120 min, = 0.0012 min), separately and/or simultaneously, under UV-visible light illumination as well as excellent recyclability and photostability. Samples with interlayer expanded MoS nanostructures were particularly more efficient in the removal of smaller species (CrO) as compared to larger (MB) dye molecules. The prepared hybrid aerogel membranes show promising behavior for application in water purification, representing a significant advancement in the use of self-supported aerogel membranes for photocatalytic applications in liquid media.
为了解决与使用非支持性纳米材料相关的问题，特别是二硫化钼（MoS），我们报告了制备自支撑混合气凝胶膜的方法，该方法将具有机械稳定性和优异的结构特性的基于细菌纳米纤维素（BC）的有机大/介孔支架与 MoS 纳米结构的优异吸附-共光催化性能和高污染物去除性能相结合。通过控制水热生长和精确调整合成参数，我们获得了具有独特形态的基于 BC/MoS 的多孔、自支撑和稳定的混合气凝胶，这种形态是由于量子受限光催化 MoS 纳米结构（2-4nm 晶粒尺寸）在 BC 纳米纤维上的分子精度涂层所致。这些 BC/MoS 样品具有高的比表面积（97-137m·g）和孔体积（0.28-0.36cm·g）以及可控的层间距离（0.62-1.05nm）在 MoS 纳米结构中。通过用纳米结构 MoS 对 BC 进行改性，通过吸附和光催化机制，使混合气凝胶的污染物去除效率得到了提高，这一点通过使用专门设计的包含所开发的光活性/吸附性 BC/MoS 混合膜的膜光反应器进行的详细研究得到了证实。最重要的是，所制备的 BC/MoS 气凝胶膜在光辅助去除有机染料（亚甲蓝（MB））分子（120min 内去除 96%， = 0.0267min）和重金属离子（120min 内去除 88%Cr(VI)， = 0.0012min）方面表现出高的性能，分别和/或同时在紫外-可见光照射下，以及良好的可回收性和光稳定性。与较大的（MB）染料分子相比，具有层间扩展 MoS 纳米结构的样品在去除较小的物种（CrO）方面更为有效。所制备的混合气凝胶膜在水净化应用中表现出良好的应用前景，这代表了自支撑气凝胶膜在液体介质中光催化应用的重大进展。
