With the rapid progress of society, the level of industrial development has reached an unprecedented height, the Earth's environment has suffered irreversible pollution and destruction [[1], [2], [3]]. Water pollution has become one of the key issues related to human health under the rapid extension of industrialization [4] and the influence of human activities [5]. Corresponding treatment technologies for different pollutants in water have been proposed, including biochemical methods [6], artificial wetlands [7], membrane separation technologies [8,9], advanced oxidation process [[10], [11], [12]], flocculation sedimentation [13], and adsorption methods [14]. Biochemical methods have become the preferred solution for organic wastewater treatment due to their low cost, long continuous operation time, and mild conditions [15]. However, wastewater containing heavy metals can easily cause poor biochemical performance, toxicity to microorganisms or other treatment materials, so the removal of heavy metals is a prerequisite for deep purification of wastewater [16]. Heavy metals in water bodies have also become a typical water pollution problem, mainly involved in industries such as printing and dyeing, electroplating, mining, metallurgy, chemical engineering, etc. [17] The discharge of wastewater containing heavy metals into the environment can cause large-scale natural water pollution, indirectly affecting soil and air, and ultimately threatening human life, health, and safety [18]. Common toxic metals include Pb, Cd, Hg, Cu, Mn, and Cr, among others. At present, the global water environment is universally threatened by heavy metals pollution, primarily characterized by complex contamination states and distinct spatial distribution patterns of total metal concentrations [19]. Relevant studies indicates that over 80 % of water bodies are contaminated with heavy metals in China [20], with the most severe pollution found in the Yangtze River, Yellow River, and Liao River basins [21]. The decline of heavy metals pollution in water bodies driven by the global water cycle will seriously affect human water safety, so the disposal of heavy metals in water is a necessary means to ensure water safety [22,23].

Compared with the removal of organic matter in wastewater [24], the removal of heavy metals seems to be a very severe challenge [25]. Without timely treatment of wastewater containing heavy metals, heavy metals entering living organisms will accumulate and accumulate in tissue structures and cells [26,27], particularly in the liver and kidneys, causing organ damage and posing a serious threat to living organisms survival safety [28]. Of course, the growth metabolism and reproduction of living organisms require trace amounts of heavy metals. However, excessive intake of heavy metals can lead to acute and chronic toxicity, including oxidative stress, developmental and reproductive damage, genetic toxicity effects, and potential carcinogenicity [29]. Especially, among numerous toxic heavy metals, Pb and Cd have received widespread attention due to their persistent bioaccumulation and toxicological effects [30]. Pb is among the most hazardous heavy metals in wastewater, characterized by a long biological half-life of 10–35 years and pronounced bioaccumulation potential, inducing a range of physiological, biochemical, and behavioral impairments upon substantial exposure [31]. Cd is non-biodegradable with strong persistence, and even low levels pose a significant ecological threat due to its high toxicity [32]. According to guidelines established by the World Health Organization (WHO) and the Environmental Protection Agency (EPA), the anthropogenic sources, toxicological profiles, and provisional safety limits for Cd and Pb are presented in Table 1 [33]. In the context of heavy metals posing a serious threat to human life health and safety, a series of heavy metals removal technologies in water have gradually attracted attention [34], including ion exchange method [35], flocculation sedimentation method [36], electrodeposition [37], functional membrane separation [38,39], and material adsorption method [40]. The material adsorption method has become the preferred solution for heavy metals removal in water due to its low cost and fast response speed [41,42]. Although there are numerous literature reports on the removal of Pb and Cd from water using adsorption methods [43], there is currently no systematic summary and analysis reports on the relevant adsorption materials, nor a clear overview of their application scenarios.

The core function of adsorption technology is the adsorption materials, numerous adsorption materials have been reported one after another [44], including carbon-based nanomaterials [[45], [46], [47]], zeolite [[48], [49], [50]], bio-derived materials [51], magnetic nanocomposites [52], mesoporous clay minerals [53], synthetic ion exchange resins [54], chitosan and zeolitic structures [55], silica-based gels [56], and metal-organic framework materials [57]. Most adsorption materials have achieved significant breakthroughs in heavy metals adsorption capacity, but their stability, service life, renewability, selectivity, and practical industrial application scenarios in complex water bodies have not yet been reflected in most research [58]. In addition, most adsorption materials also have disadvantages such as difficulty in controlling internal pore size and inability to control material morphology [59]. To address these challenges, there is an urgent need to develop advanced, structurally tunable porous materials to enhance adsorption performance, overcome current limitations, and ensure the cost-effective synthesis and sustainable recovery of these adsorbents [60]. In this regard, MOF materials have become promising candidate materials for purifying polluted water systems due to their strong adsorption performance, large adsorption capacity, controllable material structure, directional control of pore channels, and certain selectivity [61], thereby reducing the adverse effects of pollutant emissions on the environment [62]. In addition, MOF materials also have broad development prospects in the fields of photocatalysis [63], electrocatalytic organic degradation [64], chemical synthesis, and CO2 reduction [65].

MOF materials are typical representatives of directed synthesis of organic and inorganic materials [66], its utilization direction covers industries such as energy, chemical, and environmental [67]. Especially, strong adsorption capacity advantages have been demonstrated in the treatment of organic pollutants and heavy metals, mainly including organic compound rhodamine B [68] and heavy metals(Ni [69], Cd [70], and Pb [71]). In addition, these material exhibits rapid response, high sensitivity, and selectivity towards Pb and Cd [72]. Typically arising from the self-assembly of metal ions or clusters with rigid organic linkers that contain nitrogen and oxygen [73]. Over the past decade, MOF materials have garnered significant research interest as innovative materials for the detoxification and purification of heavy metals from water [74]. Ahmed S. Mubarak et al. [75] used MOF materials compounds to evaluate their effectiveness in removing common heavy metals from aqueous solutions, including Pb, Cd, As, and Cr, and found that MOF materials have adjustable structures and high adsorption efficiency. Kosar Hikmat Hama Aziz et al. [76] Reviewed MOF materials adsorption has been proven to be cost-effective and effective in removing various water pollutants such as heavy metals, organic dyes, and persistent organic compounds due to its excellent physical and chemical properties. In order to further improve the adsorption and selectivity performance of MOF materials, their functionalization has gradually received attention [77]. Incorporating organic groups into MOF materials enhances their affinity for metal ions, rendering them exemplary adsorbents for diverse purification technologies [78]. Furthermore, MOF materials can be synthesized with metal nodes featuring diverse geometric configurations, such as Zn, Cu, Mg, Ca, Zr, Ti, Co, Cd, and others [79]. Although there are many reports on MOF materials designed for Pb and Cd adsorption, many materials exhibit high adsorption capacity and selectivity for single metal, thus there is still significant potential for development in multi-metal co-removal [80]. Consequently, developing practical MOF materials that are more durable, adaptable to multiple scenarios, have significant selectivity and regeneration performance, especially those with enhanced hydrothermal stability, while being cost-effective and easy to prepare and functionalize for synergistic adsorption of various metals or direct application in wastewater treatment, remains a formidable challenge [81].

This review examines recent advances in MOF materials for aqueous Pb and Cd removal, summarizes the synthesis methods and adsorption effects of common MOF materials, analyzes the shortcomings of different materials in practical applications, clarifies the application scenarios of different MOF materials, and proposes several key research directions for the future use of MOF materials to separate, purify, and recover heavy metals from wastewater. This review aims to provide theoretical support for researchers in the field of MOF materials, reduce the time and workload of literature pre-research, and provide basic guidance for beginners.