Deep insights into LDH reconstruction for enhanced capacitive deionization

To ensure the availability of safe and sustainable freshwater resources, capacitive deionization (CDI) has emerged as a promising technology for the treatment of seawater and wastewater. The choice of electrode materials plays a critical role in CDI, as it directly influences the adsorption performance. However, traditional carbon materials are limited by their low adsorption capacity and poor cycling stability, which hinder their practical application in CDI. To overcome these limitations, layered double hydroxides (LDHs) have garnered significant attention due to their larger interlayer spacing and strong ion storage capability, making them highly promising for real-world CDI applications. Despite their advantages, few reviews have comprehensively addressed the adsorption performance and potential challenges of LDHs produced through various design strategies in the CDI field, thus impeding the cross-referencing and further development of these strategies. This paper presents a thorough review of the adsorption performance and design strategies for LDHs, with an emphasis on interface, surface, and structural engineering to enhance CDI efficiency, and compares the advantages of different design approaches. Additionally, it highlights several key challenges in improving the adsorption performance of LDHs and proposes corresponding solutions. The insights provided in this review aim to guide the development of high-performance LDHs-based electrodes, paving the way for more efficient and durable CDI technologies.