Green Synthesis and Modification of RuO2 Materials for the Oxygen Evolution Reaction

Abstract

Ion exchange method as a green synthesis route is proposed to prepare hydrous ruthenium oxide nanoparticles (H-RuO 2). Calcination of H-RuO 2 at 350°C resulted in the crystalline rutile RuO 2 nanoparticles (C-RuO 2). Treatment of H-RuO 2 with 20 vol% ammonium hydroxide solution under microwave irradiation and calcination at 350°C resulted in a highly electrocatalytic active crystalline RuO 2 nanoparticles (A-C-RuO 2). Electrocatalytic performances of H-RuO 2 , C-RuO 2 and A-C-RuO 2 for the oxygen evolution reaction in 0.50 mol L −1 H 2 SO 4 medium are evaluated and compared. Improved performances towards the oxygen evolution reaction are observed for A-C-RuO 2 when compared to C-RuO 2. Based on XRD, TEM, XPS and Raman characterizations performed on all the specimens, it is deduced that the physicochemical properties (crystallinity, mean crystallite size, level of hydrous rutile content) are varied for A-C-RuO 2 when compared to C-RuO 2. Structure-property correlation has been established to describe the higher electrocatalytic activity of A-C-RuO 2 .

Revealing the pH-Universal Electrocatalytic Activity of Co-Doped RuO2 toward the Water Oxidation Reaction

“…These red shifts might have originated from the more crystalline nature of Co-RuO 2 as compared to the bare RuO 2 and from the size confinement effect induced by the incident phonon in the RuO 2 after the incorporation of Co ions over the RuO 2 structure as well. From the Raman analysis, it is confirmed that Co is incorporated and well polarized with the RuO 2 structure. − After confirming the formation of Co-RuO 2 , field-emission scanning electron microscope (FE-SEM) analysis was carried out to know the morphological features, which revealed the aggregated nanorod-like structure of Co-RuO 2 , and the corresponding results are given in Figure a–c . Energy-dispersive spectroscopy (EDS) analysis at the FE-SEM mode was carried out to confirm the presence of all of the expected elements like Ru, Co, and O with high purity, as can be seen from the EDS spectrum in Figure S3.…”

“…The crystal structure engineering of Ru-based materials via the doping of an alien cation is a common technique for improving the catalytic activity. Generally, doping alien cations in Ru-based materials specially in the RuO 2 lattice leads to alternation of the d-band center close to the Fermi level, thereby making the catalyst surface suitable for water adsorption with optimum adsorption energy with a higher OER activity in universal pH conditions. − …”

Platinum Nanocrystal Assisted by Low‐Content Iridium for High‐Performance Flexible Electrode: Applications on Neural Interface, Water Oxidation, and Anti‐Microbial Contamination

“…Table 2 compared the performance of some typical metal oxide electrocatalysts for OER in 0.5 m H 2 SO 4 widely reported in literature. [42][43][44][60][61][62][63][64] Notably, IrO x /Pt flower exhibited superior OER performance in 0.5 m H 2 SO 4 compared to other Ru-based or Ir-based catalysts, which could be attributed to Pt nanocrystal structure loading IrO x NPs.…”

Mn-Doped Highly Dispersed RuO2 Catalyst with Abundant Oxygen Vacancies for Efficient Decarboxylation of l-Lysine to Cadaverine

“…Generally, the small peak locating at 530.0 eV corresponded to the crystal lattice oxygen (metal−oxygen bonds) in RuO 2 crystals. 14,48,49 Unlike the uniform assignment of the lattice oxygen around 530.0 eV, there was a little divergence in the accurate assignment of oxygen vacancies. For example, in a study, 50 the peak at the binding energy of 530.5 eV was assigned to the surface oxygen vacancies.…”