Carboxylation of sodium arylsulfinates with CO2 over mesoporous K-Cu-20TiO2

A mesoporous ternary metal oxide (K-Cu-20TiO2) from a simple sol–gel method was prepared to catalyze heterogeneously the carboxylation reaction of various sodium arylsulfinates under atmospheric carbon dioxide.

PREDICTION OF BONDING ENERGY BY STRUCTURAL DESCRIPTORS OF METAL NANOALLOYS

Обсуждается проблема предсказания энергии связи для тернарных металлических наночастиц и построение моделей обучения на базе структурных дескрипторов. Были построены регрессионные зависимости удельной межатомной энергии связи для тернарной наносистемы Au - Ag - Cu. Использовался ряд из пяти радиальных признаков, зависящих от попарного межатомного расстояния дескрипторов структуры наночастицы. Для более корректной оценки точности была применена кросс-валидация, далее полученные на валидационных частях выборки результаты усреднялись. Полученная модель ограниченно предсказывает значение удельной межатомной энергии связи внутри группы данных для наночастиц одного состава, а для всей выборки средняя по модулю ошибка составляет 14%. При этом модель практически безошибочно определяет состав наночастицы из нескольких вариантов. Наибольшее значение коэффициента детерминации на всей выборке получено с помощью ансамблевого алгоритма случайный лес. Обнаружена отрицательная корреляция между энергией связи наносплава и положением первого пика радиальной функции распределения для атомов меди. The problem of predicting the binding energy for ternary metal nanoparticles and the construction of learning models based on structural descriptors are discussed. Regression dependences of the specific interatomic bond energy were constructed for the ternary Au - Ag - Cu nanosystem. A number of five radial features were used, depending on the pairwise interatomic distance of the nanoparticle structure descriptors. For a more correct assessment of the accuracy, cross-validation was applied, then the results obtained on the validation parts of the sample were averaged. The resulting model limitedly predicts the value of the specific interatomic binding energy within a group of data for nanoparticles of the same composition. For the entire sample the average error in modulus is 14 %. In this case, the model almost accurately determines the composition of a nanoparticle of several variants. The largest value of the coefficient of determination in the entire sample was obtained using an ensemble random forest algorithm. A negative correlation was found between the binding energy of the nanoalloy and the position of the first peak of the radial distribution function for copper atoms.

Novel Ternary Metal Oxide Nanoparticles (La2Cu0.8Zn0.2O4) as Potential Photocatalyst for Visible Light Photocatalytic Degradation of Methylene Blue and Desulfurization of Dibenzothiophene

In this work, we present preparation of novel ternary metal oxide nanoparticles, La2Cu0.8Zn0.2O4 (LCZO), using simple co-precipitation method. The crystalline structure, morphology and composition of the prepared LCZO nanoparticles were characterized by XRD, SEM and EDX analysis. The DRS investigation shows the LCZO nanoparticles have considerable light absorption in the visible light region. Also, the LCZO nanoparticles possess the band-gap energy of 2.82 eV. To investigate the visible light photocatalytic potential of the prepared LCZO nanoparticles, two photocatalytic reactions were conducted toward degradation of methylene blue (MB) solution and desulfurization of dibenzothiophene (DBT). In the presence of 3:1 molar ratio of H2O2/DBT, the high photocatalytic desulfurization rate (93.7%) of dibenzothiophene (DBT) was obtained over 0.2 gr of LCZO photocatalyst. In addition, the photocatalytic degradation rate of methylene blue (MB) solution was 91.4%. The mechanism involving both photocatalytic reactions were studied using different radical scavenging agents which showed that the hydroxyl radicals (OH•) are responsible for highly efficient desulfurization and degradation reactions. Moreover, reusability experiments reveal that the prepared LCZO photocatalyst has great stability and recyclability for both desulfurization of DBT and degradation of MB after 6 reaction cycles.