Resumo em Inglês:

This work produced chemically activated sugarcane bagasse-based activated carbon (AC) for the controlled release of urea. Fourier transform infrared (FTIR) and Raman analysis confirmed the presence of graphitic structures and multiple oxygen-containing functional groups. After the solid-state reaction that formed the material, their surface area reached 1401 m2 g-1 for the sample prepared with a pyrolysis temperature of 400 °C, a concentration of sodium hydroxide equivalent to 11 mol L-1, and an activation temperature of 900 °C (AC 400-11-900). Zeta potential measures indicated negative charges at pH > 4, reaching almost (–50 mV) at pH 9. The adsorptive capacity of the AC with the highest surface area was equal to (758.7 ± 263.8) mg g-1. Nevertheless, the matrix did not release the urea molecules previously adsorbed into it, which is appealing for fertilizer-releasing purposes because the activated carbon would be able to re-adsorb the non-absorbed urea molecules, sustaining nutrient availability for longer periods.

Resumo em Inglês:

The increase in anthropogenic activity over time has led to an exponential increase in greenhouse gas emissions, especially CO2. Proftable technologies for CO2 capture and separation are conspicuous, and porous biochars derived from biomass waste can be a useful solution. Herein, we produced activated nitrogen-doped biochars for CO2 capture from corn husk waste, urea and K2CO3, named N-Bio-X (X = 600, 700, and 800 °C). N-Bio-X exhibited microporosity and different nitrogen contents and thus played an important role in the adsorption of CO2. N-Bio-700 exhibited the highest CO2 adsorption capacity, fastest adsorption kinetics and excellent stability after multiple adsorption-desorption cycles. N-Bio-600 showed excellent CO2/N2 selectivity, induced by nitrogen sites, particularly pyridinic and graphitic nitrogen. The cost-effectiveness of the raw material, coupled with its high adsorption capacity, rapid kinetics, and stable properties, provided highly promising N-doped biochars for practical implementation in CO2 capture and separations in postcombustion processes.

Resumo em Inglês:

Niobium pentoxide shows an interesting reactivity that allows the control of different aspects of its morphology and chemistry. In this study, Nb2O5 nanoparticles were modified with protoporphyrin IX (PPIX) and tris(ethynylphenyl) pyrene derivative (PyPh3) by using 3-aminopropyltriethoxysilane as linkage group and used as photosensitizers against lung cancer. The antitumor photoactivity against the A549 tumor cell line as a model of in vitro study showed half maximal inhibitory concentration (IC50) ca. 15 μmol L-1 for both materials and the absence of dark activity, indicating the viability of dye-modified Nb2O5 as a photodynamic therapy (PDT) agent.