No abstract

Methyl parathion (MP) is one of the most neurotoxic pesticides. An inexpensive and reliable one-step degradation method of MP was achieved through an aqueous suspension of copper(I) oxide nanoparticles (NPs). Three different NPs sizes (16, 29 and 45 nm), determined with X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM), were synthesized using a modified Benedict’s reagent. 1H nuclear magnetic resonance (NMR) results show that the hydrolytic degradation of MP leads to the formation of 4-nitrophenol (4-NPh) as the main product. While the P=S bond of MP becomes P=O, confirmed by 31P NMR. Although Cu2O is a widely known photocatalyst, the degradation of methyl parathion was associated to the surface basicity of Cu2O NPs. Indirect evidence for the basicity of Cu2O NPs was achieved through UV–vis absorption of 4-NPh. Likewise, it was shown that the surface basicity increases with decreasing nanoparticle size. The presence of CuCO3 on the surface of Cu2O, identified using X-ray photoelectron spectroscopy (XPS), passivates its surface and consequently diminishes the degradation of MP.

Synthesis of carbon nanotubes (CNTs) using porous anodic alumina membrane (PA) as template and the chemical functionalization of their inner walls is presented. The CNT were prepared by catalyst-free process using the pyrolysis of liquid aerosol of toluene: ethanol (1:1 v/v). The surface modification of the inner surface walls of CNT was performed using the gas phase synthesis by aliphatic amines (1,8-diaminooctane, DO). SEM, TEM and XPS analysis confirmed the morphology of prepared CNT inside of PA pores and their successful functionalization by amino groups. The presence and growth of interesting carbon nanoparticle inside CNT was observed during amination process. We hypothesized their origin as nanodiamonds formed as a result of the heat treatment in the presence of air that support etching mechanism and defects formation which acts as a diamond growth sites.