Cleiser Thiago Pereira da Silva

AuNp@MOF composite as electrochemical material for determination of bisphenol A and its oxidation behavior study

A composite material based on a metal organic framework (MOF), nanowhisker of Al2O3 silanized with (3-aminopropyl)triethoxysilane (APTES) and gold nanoparticles (AuNp) was synthesized and characterized. This material was used to prepare an electrode based in carbon paste (CPE) and applied as a sensor for the determination of bisphenol A (BPA). The electrochemical characterizations and behaviour of the electrode containing the AuNp@MOF composite exhibited a 2.3 higher electroactive surface area, when compared with just CPE. Using differential pulse voltammetry (DPV), it can be noted that the presence of AuNp plays an important role in enhancing the analyte signal detection of BPA 2.5-fold. A linear increase in emphasizing the response as a function of analyte concentration is demonstrated. In this account, we believe that this composite may be applied in analyticals methods for the determination of BPA and others endocrine disruptors.

Synthesis of zeolite from multilayer food packing and sugar cane bagasse ash for CO2 adsorption

The X/A zeolite crystal mixtures were synthesized using sugar cane bagasse ash (SCBA) as a silicon source and multilayer food packing (MFP) as an aluminum source under hydrothermal conditions at 80 °C for 79–296 hours. The silicon was extracted by alkaline fusion for 40 min at 550 °C with an alkali–SCBA weight ratio of 1:1. The aluminum solution was obtained from MFP using NaOH 1 M (3:1 water–acetone) solution. The synthesized zeolites were analyzed by XRD, FTIR, SEM, and BET. In the XRD results, most of the signals were indexed to zeolite X, and some signals were indexed to zeolite A. The vibration bands in the region 1200–400 cm−1 suggested the presence of the double-six-ring (D6R) zeolite X structure. The crystal morphology is characteristic of the zeolite X, and the specific area found by the BET method was 810.47 m2 g−1. The zeolite with the higher specific area was applied in the CO2 adsorption process until it reached 25 bar by the gravimetric method. The experimentally adsorbed amounts were adjusted with the Langmuir, Freundlich, and Toth models.