## 1 Introduction  
The decrease in environmental quality made clear the need to fill the void between development and sustainability. High amounts of pollutants end up in the aquatic environment [1]. Among the different xenobiotics that enter into the environment, synthetic dyes are a common class of organic pollutants with high concentrations in wastewater since they are used in many different industries (paper, printing, textiles, food, and pharmaceutical industry) [2; 3; 4; 5]. Different technologies have been suggested for dye removal from effluents, among which adsorption [6; 7; 8; 9] and photocatalysis [10; 11; 12] are considered suitable mostly due to the environmentally friendly character of the process. Adsorption offers the benefit of simplicity, high efficiency, and cost-effectiveness. On the other hand, photocatalysis is highly favorable when solid materials are applied as photocatalysts and when solar light is used for the decomposition of organic pollutants. In both processes, efficiency is driven by the properties of the material used. Regarding adsorption, many different types of materials have been developed and applied in dye removal from the aquatic phase [13; 14; 15]. Metal-organic frameworks (MOFs) have been effectively applied as solid absorbing media including dye removal [2; 16; 17; 18; 19; 20; 21]. MOFs are highly porous synthetic materials that offer the benefit of chemical, textural, and compositional tunability [2]. In addition, they have also been applied as photocatalysts for the degradation of organic dyes [11; 22] and have been coupled efficiently with traditional photocatalysts to improve performance [16; 17; 23; 24] or the development of multifunctional composites [17; 25]. Clay minerals have been also extensively studied as adsorbents for dyes removal [19; 26; 27]. They are low-cost, nontoxic materials with significant cation exchange capacity. However, their negative charge in neutral conditions limits their application as adsorbents of anionic chemical species [28; 29]; therefore, chemical modification is required [30; 31]. TiO\({}_{2}\) is the most used photocatalyst owing to its inherent properties such as high photocatalytic activity and nontoxicity [32; 33; 34]. Among the different polymorphs of TiO\({}_{2}\), anatase is preferred mostly due to the better charge handling properties [33]. Numerous studies have applied TiO\({}_{2}\)-based materials for the degradation of dyes [35]. Formation of composites through the coupling of TiO\({}_{2}\) with MOF structures has also been exploited in photocatalytic reactions [11; 16; 17; 22; 24; 25; 36]. Clay mineral/TiO\({}_{2}\) composites have also proven to be more active than the individual counter parts in a variety of photocatalytic reactions [37; 38; 39]. Since adsorption is a prerequisite for photocatalytic degradation reactions, adsorption of dyes on TiO\({}_{2}\)[40; 41] or MOF/TiO\({}_{2}\) composites [42] has also been investigated. As expected, pure TiO\({}_{2}\) materials present much lower adsorption capacity than MOF structures. Recently, [PERSON] et al. showed that coupling MIL-101 (Cr) with TiO\({}_{2}\) increased the adsorption performance against methyl orange (MO) (Scheme 1) [42]. In addition, the adsorption of cationic dyes onto Ui0-66/TiO\({}_{2}\) composites was not affected by the presence of TiO\({}_{2}\), while the composites presented superior photocatalytic activity [25]. Clay/MOF composites have also been developed and studied as adsorbents. However, the effect of the presence of both clay minerals and TiO\({}_{2}\) has never been studied. Herein, novel ternary composites bearing UiO-66, palygorskite, and TiO\({}_{2}\) were developed using wet chemical processes. The materials were characterized and tested as adsorbents and photocatalysts for the removal of MO from aqueous solutions. The presence of palygorskite in the composite increased the adsorption efficiency while TiO\({}_{2}\) provided photocatalytic properties able to decompose MO.