Layered Double Hydroxides (LDHs): Highly Effective Electrocatalysts for Oxygen Evolution Reaction (OER)

The oxygen evolution reaction (OER) has aroused extensive interest from materials scientists in the past decade by virtue of its great significance in the energy storage/conversion systems such as water splitting, rechargeable metal–air batteries, carbon dioxide (CO2) reduction, and fuel cells. Among all the materials capable of catalyzing OER, layered double hydroxides (LDHs) stand out as one of the most effective electrocatalysts for this reaction. LDHs are a class of inorganic compounds with a layered structure, consisting of positively charged metal hydroxide layers and intercalated anions in the interlayer space.

The unique structure of LDHs provides several advantages for OER catalysis. Firstly, the presence of metal hydroxide layers offers a large number of active sites for the adsorption and activation of oxygen species, facilitating the OER process. Additionally, the interlayer anions can serve as charge-balancing species, enhancing the electrical conductivity of LDHs and improving the overall catalytic performance.

In recent years, various strategies have been developed to enhance the OER activity of LDHs. These include doping with transition metal ions, introducing heteroatoms into the structure, and modifying the LDH surface with functional groups. These approaches aim to optimize the electronic structure and surface properties of LDHs, thereby promoting the OER kinetics and reducing energy barriers.

Moreover, the stability of LDHs as OER catalysts has also been a focus of research. The use of protective coatings, such as carbon or metal oxides, can effectively prevent the corrosion and degradation of LDHs during the OER process, leading to improved durability and long-term performance.

Overall, the exceptional electrocatalytic performance and tunable properties of LDHs make them promising candidates for efficient OER catalysis. Further research and development in this field will contribute to the advancement of renewable energy technologies and the realization of a sustainable energy future.