SBA-16 Cage-Like Porous Material Modified with APTES as an Adsorbent for Pb2+ Ions Removal from Aqueous Solution

© 2020 by the authors.Tridimensional cubic mesoporous silica, SBA-16, functionalized with aminopropyl groups, were employed as adsorbents for Pb2+ ion removal from aqueous solution. The adsorption capacity was investigated for the effect of pH, contact time, temperature, and concentration of 3-aminopropyltriethoxysilane (APTES) employed for adsorbent functionalization. The textural properties and morphology of the adsorbents were evaluated by N2 physisorption, small-angle X-ray diffraction (XRD), diffuse reflectance spectroscopy (UV-vis), and transmission electron microscopy (TEM). The functionalization of the SBA-16 was evaluated by elemental analysis (N), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). Batch adsorption studies show that the total Pb2+ ions removal was archived on adsorbent having an optimized amount of aminopropyl groups (2N-SBA-16). The maximum of Pb2+ ions removal occurred at optimized adsorption conditions: pH = 5–6, contact time 40 min, and at a low initial lead concentration in solution (200 mg L−1). Under the same adsorption conditions, the amino-functionalized SBA-16 with cubic 3D unit cell structure exhibited higher adsorption capability than its SBA-15 counterpart with uniform mesoporous channels.Financial support by FOFI UAQ-2018 is gratefully acknowledged. V. Palos-Barba and A. Moreno-Martell thank the CONACyT for the scholarships

Development of an Adsorbing System Made of DMS-1 Mesh Modified by Amino Groups to Remove Pb(II) Ions from Water

Water pollution by heavy metals represents several health risks. Conventional technologies employed to eliminate lead ions from residual or drinking water are expensive, therefore an efficient and low-cost technique is required and adsorption processes are a good alternative. In this work, the goal was to determine the adsorption capacity of a Disordered Mesoporous Silica 1 material (DMS-1) functionalized with amino groups, for Pb(II) ions removal. DMS-1 was prepared by sol-gel method and the incorporation of amino groups was performed by ex-situ method. As the source of amine groups, (3-Aminopropyl) triethoxysilane (APTES) was used and three different xNH2/DMS-1 molar ratios (0.2, 0.3, 0.4) were evaluated. In order to evaluate the incorporation of the amino group into the mesopore channels, thermal and structural analysis were made through Thermogravimetric Analysis (TGA), nitrogen adsorption–desorption at 77 K by Specific Brunauer–Emmett–Teller (SBET) method, Fourier Transfer Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS). The higher Pb(II) ions removal was achieved with the 0.3 molar proportion of xNH2/DMS-1 reaching 99.44% efficiency. This result suggests that the functionalized material can be used as an efficient adsorbent for Pb(II) ions from aqueous solution.The authors acknowledge financial support of FOFI-UAQ2018. The authors V. Palos-Barba and C. Lugo-Nabor acknowledge the CONACYT for the scholarships.Peer reviewe

Antiviral Activity of TiO₂ NPs against Tobacco Mosaic Virus in Chili Pepper (<i>Capsicum annuum</i> L.)

Tobacco mosaic virus is the etiological agent of one of the most critical diseases limiting chili pepper production. Various practices have been used to manage the disease, e.g., the use of resistant varieties and interference with the vector through chemical control. However, these practices are not helpful once the virus has been established in the plant. There is still no effective method for the sustainable management of the disease; therefore, exploring new options is required. Currently, some studies have reported the activity of TiO2 NPs against viruses in plants, although not against TMV in chili pepper. The present work aims to determine a possible direct action of TiO2 NPs against TMV and if there is a relationship between the amount of virus and symptoms. The application of TiO2 NPs at 150 μg/mL in infected pepper plants reduced symptoms and viral load and improved the morphological characteristics compared to the control. Incubation of 150 µg/mL TiO2 NPs with the virus for 6 and 8 h before infection decreased viral concentration significantly after infection compared to the control. In this work, it is reported, for the first time, that the use of TiO2 NPs is a novel practice for the control of TMV in chili pepper