Layered double hydroxides mediated persulfate activation for organic pollutants degradation: A review

The rapid development of modern industry has caused a large number of refractory organic pollutants to enter the water body, there is an urgent need for economic and efficient pollution control and reduction technologies for refractory organic pollutants. In recent years, advanced oxidation technologies (SR-AOPs) based on sulfate radicals (SO₄^•–) have attracted much attention because of their strong oxidizing properties, wide pH tolerance, and ease of operation. Different types of metal oxygen/sulfide, carbon-based materials, metal-non-metal composite materials and organic metal materials are used to activate persulfate to generate active oxygen, thereby achieving oxidative degradation and further mineralization of organic pollutants. Among them, layered double hydroxides (LDHs) show excellent reactivity and catalytic advantages in activating persulfate due to their unique layered structure advantages, anion exchangeability and guest molecule adjustability. This article reviews the current research status of LDHs and their composites as heterogeneous catalysts to activate persulfate from the aspects of catalyst type, catalytic performance and mechanism, and degradation system influencing factors, and proposes relevant prospects for the continuous improvement of the catalytic system and future development.