Enhanced hydrogen evolution reaction on highly stable titania‐supported PdO and Eu₂O₃nanocomposites in a strong alkaline solution

Abstract

Summary In this work, PdO/TiO2 and Eu2O3/TiO2 nanocomposites (NCs) were synthesized using a new facile, template‐free, and one‐step solvothermal approach and characterized by several instrumentation techniques. X‐ray photoelectron spectroscopy studies revealed the presence of oxidized form of the Pd and Eu nanoparticles within the NC materials (PdO and Eu2O3). The two catalysts exhibited remarkable activity for the hydrogen evaluation reaction (HER) in a strong alkaline solution (4.0 M NaOH) with PdO/TiO2 catalyst being the best, which recorded an exchange current density (jo) of 0.26 mA cm−2 and a Tafel slope (βc) of 125 mV dec−1. Such parameters are not far from those recorded for a commercial Pt/C catalyst (0.71 mA cm−2 and 120 mV dec−1) performed here under the same operating conditions. Eu2O3/TiO2 catalyst recorded jo and βc values of 0.05 mA cm−2 and 135 mV dec−1. The Tafel slopes 125 and 135 mV dec−1 calculated on the PdO/TiO2 and Eu2O3/TiO2 catalysts suggest a HER kinetics controlled by the Volmer step. PdO/TiO2 catalyzed the HER with a high turnover frequency of 2.3 H2/s at 0.2 V versus the reversible hydrogen electrode, while Eu2O3/TiO2 catalyst only measured a turnover frequency value of 1.25 H2/s at the same overpotential. The two catalysts exhibited excellent stability and durability after 10 000 cycles and 72 hours of controlled potential electrolysis at a high cathodic overpotential, reflecting their practical applicability. Scanning electron microscope and X‐ray photoelectron spectroscopy examinations revealed that the morphology and chemistry of both catalysts were not altered as a result of the performed long‐term stability and durability tests.

NiFeCo oxide as an efficient and sustainable catalyst for the oxygen evolution reaction

“…Hydrogen possesses outstanding properties as an energy source, such as carbon neutrality, high efficiency, and nontoxic to environment. 1 Electrocatalysis is an important emerging technology, because it is an inexpensive, clean, and environmentally friendly source of hydrogen energy. [2][3][4][5] It is a simple process by which the strong bonds in water are broken to yield oxygen and hydrogen.…”

Crystalline ZnO and ZnO / TiO 2 nanoparticles derived from tert ‐butyl N‐(2 mercaptoethyl)carbamatozinc( II ) chelate: Electrocatalytic studies for H 2 generation in alkaline electrolytes

“…This is clear from the catalysts' E HER values presented in Table 6. It follows from Figure 10A that the supporting material, namely TiO 2 NPs, exhibits considerable HER catalytic activity, even in the dark 71,72 . This is clear from its E HER value (−390 mV vs RHE), which is 360 mV vs RHE lower than that determined for bare GC electrode, −750 mV vs RHE.…”

Hydrogen Evolution Reaction-From Single Crystal to Single Atom Catalysts

“…Electrocatalytic activities of Titania supported PdO and Eu 2 O 3 , prepared by template-free one-step solvothermal method, were reported by Ibrahim et al Pd or Eu salt was allowed to react with titanium butoxide in dimethyl sulfoxide (DMSO). Such preparation approach yielded PdO/TiO 2 with the average particle size of 46 ± 0.78 nm and better HER activity and stability, compared to Eu 2 O 3 /TiO 2 obtained by the same method with the average particle size of 39 ± 0.67 nm [107].…”