Optimization of the synthesis conditions for LaNiO3 catalyst by microwave assisted citrate method for hydrogen production

LaNiO3 was prepared by microwave assisted citrate method. The effect of the synthesis condition such as, the operating microwave power and the microwave irradiation time, on structural, surface and catalytic properties was investigated by XRD, SEM, Tafel linear polarization and impedance measurements. The XRD results suggested successful incorporation of Ni3+ at the La3+ cations sites confirming the formation of the hexagonal distorted rhombohedral perovskite phase of LaNiO3 at all the investigated microwave operating powers and irradiation times. The average particle size ranges between 18 and 32 nm. The largest surface area (ca. 25 m2 g−1) and the highest catalytic activity for LaNiO3 prepared by the microwave assistant-citrate method toward the hydrogen evolution reaction (HER) were obtained at an operating microwave power of 720 W and increased by increasing the microwave irradiation time. In addition, the reaction order, the activation energy and the reaction mechanism were identified.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (80 K)Download as PowerPoint slideHighlights► LaNiO3 perovskite was prepared by microwave-assistant citrate method. ► Hexagonal distorted rhombohedral perovskite phase of LaNiO3forms. ► Microwave power and time of synthesis affected perovskite electrocatalytic activity. ► Highest rate for HER obtained with microwave power of 720 W. ► Catalyst has dimensions ranging from 18 nm to 32 nm.