Ultra-fast synthesis of Ti/Ru0.3Ti0.7O2 anodes with superior electrochemical properties using an ionic liquid and laser calcination

Here, we combine CO2 laser heating and an ionic liquid solvent (i.e., methylimidazolium hydrogensulfate HMIM+ HSO4–) as an innovative route to produce Ti/Ru0.3Ti0.7O2 anodes. For comparison purposes, the anodes were also prepared using conventional thermal treatment (in a furnace), and by the standard polymeric precursor method (also known as the Pechini method). For the laser heating, the anodes were heated at a power density of 0.4 W mm−2 up to 550 °C and kept at this temperature for 40 s, followed by instantaneous cooling. Using these conditions, the total time spent to produce an anode (considering cooling) is just 9.7 min. It represents a remarkable reduction in 446-fold and 359-fold when compared with the conventional heating for Pechini and IL methods, respectively. The laser-prepared anodes presented an increase of 63.4% and 53.8% in the voltammetric charge, while the charge transfer resistance decreases 9.6-fold and 17.3-fold using IL and Pechini methods, respectively, when compared with their correspondent furnace-made ones. Finally, superior electrocatalytic activity toward the removal of the model pollutant atrazine is observed for the laser-prepared anodes. The anode produced using laser and the IL method is the most efficient, removing 81% of atrazine in 60 min, and presents the highest kinetic rate (0.062 min−1) at the lowest energy consumption (0.179 kWh L–1). The excellent electrocatalytic response of the anodes innovatively synthesized in this study characterizes them as an encouraging advance in the search for efficient materials to be applied in the electrochemical oxidation of organic compoundsAquí, combinamos el calentamiento por láser de CO 2 y un disolvente líquido iónico (es decir, hidrogenosulfato de metilimidazolio HMIM + HSO 4 - ) como una ruta innovadora para producir ánodos de Ti / Ru 0,3 Ti 0,7 O 2 . Para fines de comparación, los ánodos también se prepararon utilizando un tratamiento térmico convencional (en un horno) y por el método estándar de precursor polimérico (también conocido como método Pechini). Para el calentamiento por láser, los ánodos se calentaron a una densidad de potencia de 0,4 W mm -2hasta 550 ° C y se mantiene a esta temperatura durante 40 s, seguido de enfriamiento instantáneo. Usando estas condiciones, el tiempo total empleado para producir un ánodo (considerando el enfriamiento) es de solo 9,7 min. Representa una reducción notable de 446 veces y 359 veces en comparación con el calentamiento convencional para los métodos Pechini e IL, respectivamente. Los ánodos preparados con láser presentaron un aumento de 63,4% y 53,8% en la carga voltamétrica, mientras que la resistencia de transferencia de carga disminuye 9,6 veces y 17,3 veces usando los métodos IL y Pechini, respectivamente, en comparación con sus correspondientes fabricados en horno. Finalmente, se observa una actividad electrocatalítica superior hacia la eliminación del contaminante modelo atrazina para los ánodos preparados con láser. El ánodo producido mediante láser y el método IL es el más eficiente, eliminando el 81% de la atrazina en 60 min.−1 ) con el menor consumo de energía (0,179 kWh L –1 ). La excelente respuesta electrocatalítica de los ánodos sintetizados de manera innovadora en este estudio los caracteriza como un avance alentador en la búsqueda de materiales eficientes para ser aplicados en la oxidación electroquímica de compuestos orgánicos

Understanding the effect of the high hydrophobicity of the laser-prepared Ti/SnO₂-Sb-La₂O₃anode on its electrocatalytic properties

SnO2-Based materials have attracted much attention in the electrochemical oxidation field due to their high electrocatalytic activity. However, efforts are still required to improve their physical and electrochemical properties. Here we employed a CO2 laser thermal process, as a substitute to conventional furnace heating, for the synthesis of two SnO2-based anodes-Ti/SnO2-Sb2O5 and Ti/SnO2-Sb-La2O3. Compared with anodes made using conventional heating, the laser-prepared anodes show a more compact surface and a change from hydrophilic to super-hydrophobic wetting properties. Energy-dispersive X-ray spectroscopy and X-ray diffraction data reveal the uniform distribution of Sn, Sb, and La, as well as the formation of the desired oxides, respectively. The oxidation state and chemical composition were confirmed by X-ray photoelectron spectroscopy. Notably, the laser-prepared anodes exhibit a positive shift in the oxygen evolution overpotential, especially for the Ti/SnO2-Sb-La2O3 anode, and a 2-fold reduction in the charge transfer resistance. The electrochemical degradation of 4-nitrophenol (4-NP) was investigated in aqueous solutions by UV-Vis spectra employing all anodes produced. The results showed that laser-prepared Ti/SnO2-Sb-La2O3 displays the highest degradation efficiency at the lowest energy consumption. Also, a mechanism for the 4-NP oxidation at the SnO2-based anodes under the current working conditions is proposed. Finally, the notable reduction in processing time and energy spent using laser heating makes it a feasible alternative to produce SnO2-based anodes. Their improved properties enhance the potential of these anodes to be applied in the electrochemical treatment of polluted waters.Large Scale Energy Storag