Degradation of 4-Chlorophenol in a Batch Electrochemical Reactor Using BDD Electrodes

The influence of current density (j) (0.25, 0.30, 0.25 and 0.40 A/cm2), initial pH (2.6, 6.5 and 12), stirring speed (As) (400, 500 and 600 rpm), and initial concentration of 4-chlorophenol ([4-CP]0) (300, 500 and 700 mg/L) on degradation of persistent pollutant in a batch electrochemical cell without divisions is presented in this paper. The electrochemical cell was composed of two boron-doped diamond electrodes (BDD). The results of the study showed that best conditions for total degradation of 4-CP were: j of 0.40 A/cm , initial pH of 6.5, As of 500 rpm, and [4-CP]0 of 500 mg/L, after 150 min of reaction time. Removal of total organic carbon (TOC) was 83% at these conditions. The byproducts were identified by UHPLC. This allowed for the proposal of a degradation pathway of 4-CP at the best conditions. Furthermore, these results demonstrate that the electrochemical method employed in this study allows high percentages (96%) of degradation of 4-CP and that the process is applicable to wastewater treatment.CONACYT 26909

A Promising Thermodynamic Study of Hole Transport Materials to Develop Solar Cells: 1,3-Bis(N-carbazolyl)benzene and 1,4-Bis(diphenylamino)benzene

The thermochemical study of the 1,3-bis(N-carbazolyl)benzene (NCB) and 1,4-bis(diphenylamino)benzene (DAB) involved the combination of combustion calorimetric (CC) and thermogravimetric techniques. The molar heat capacities over the temperature range of (274.15 to 332.15) K, as well as the melting temperatures and enthalpies of fusion were measured for both compounds by differential scanning calorimetry (DSC). The standard molar enthalpies of formation in the crystalline phase were calculated from the values of combustion energy, which in turn were measured using a semi-micro combustion calorimeter. From the thermogravimetric analysis (TGA), the rate of mass loss as a function of the temperature was measured, which was then correlated with Langmuir’s equation to derive the vaporization enthalpies for both compounds. From the combination of experimental thermodynamic parameters, it was possible to derive the enthalpy of formation in the gaseous state of each of the title compounds. This parameter was also estimated from computational studies using the G3MP2B3 composite method. To prove the identity of the compounds, the 1H and 13C spectra were determined by nuclear magnetic resonance (NMR), and the Raman spectra of the study compounds of this work were obtained