Application of layered double hydroxide-biochar composites in wastewater treatment: Recent trends, modification strategies, and outlook

In recent years, layered double hydroxide-biochar (LDH-BC) composites as adsorbents and catalysts for contaminants removal (inorganic anions, heavy metals, and organics) have received increasing attention and became a new research point. It is because of the good chemical stability, abundant surface functional groups, excellent anion exchange ability, and good electronic properties of LDH-BC composites. Hence, we offer an overall review on the developments and processes in the synthesis of LDH-BC composites as adsorbents and catalysts. Special attention is devoted to the strategies for enhancing the properties of LDH-BC composites, including (1) magnetic treatment, (2) acid treatment, (3) alkali treatment, (4) controlling metal ion ratios, (5) LDHs intercalation, and (6) calcination. In addition, further studies are called for LDH-BC composites and potential areas for future application of LDH-BC composites are also proposed.

Automated summary

Layered double hydroxide-biochar (LDH-BC) composites have gained increasing attention as adsorbents and catalysts for contaminant removal due to their good chemical stability, abundant surface functional groups, excellent anion exchange ability, and good electronic properties. Strategies for enhancing the properties of LDH-BC composites, such as magnetic treatment, acid treatment, and LDHs intercalation, are highlighted in this review, with further studies and potential future applications being recommended.