AsianScientist (Feb. 5, 2019) – In a study published in the journal Small, a team of scientist in South Korea has developed a nickel-based hydroxide catalyst that can split water to generate renewable energy.
In the search for greener energy sources, scientists have found that water molecules can be broken apart in an electrochemical reaction known as electrolysis, allowing them to convert energy from the sun or other renewable sources into chemical energy. However, electrochemically splitting water molecules requires an overpotential—an excess voltage that has to be applied so that the necessary reactions can occur.
In the present study, researchers led by Professors Im Hyunsik and Kim Hyungsang at Dongguk University, South Korea, have developed electrocatalysts to raise the efficiency of water-splitting. By intercalating polyoxovanadate (POV) nanoclusters into nickel hydroxide (Ni(OH)2) arranged in ordered layers, the researchers were able to improve the conducting and morphological properties of their electrolysis system.
To obtain the necessary structure for their electrcatalyst, the researchers used a method called chemical solution growth (CSG), wherein a highly saturated solution is prepared and the desired material structure naturally forms as the solutes precipitate in a predictable and controlled fashion.
The team demonstrated that the resulting house-of-cards-like structure greatly reduced the overpotential needed for the electrolysis of water. The POV nanoclusters increased the spacing between the Ni(OH)2 layers and induced the formation of micropores, which increased the surface area of the final material and the number of catalytic sites where water molecules can be split.
“Our results demonstrate the advantages of the CSG method for optimizing the pore structure of the resulting material,” Im explained. “The facile CSG deposition of nanohybrid materials may be useful for applications such as the production of lithium-ion batteries and biosensors.”
The article can be found at: Gunjakar et al. (2018) Two‐Dimensional Layered Hydroxide Nanoporous Nanohybrids Pillared with Zero‐Dimensional Polyoxovanadate Nanoclusters for Enhanced Water Oxidation Catalysis.
Source: Dongguk University; Photo: Pexels.
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