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This review critically examines the latest advancements in clay mineral-based photocatalysts for water purification. Clay minerals, owing to their natural abundance, low cost, and unique physicochemical properties, have emerged as promising candidates for enhancing photocatalytic efficiency. This article delves into various activation methods for clay minerals, including acid, alkali, calcination, and mechanochemical activation, highlighting their roles in enhancing surface area, creating active sites, and improving photocatalytic performance. Moreover, the review explores various modification strategies for photocatalysts, such as doping with metal and non-metal ions, deposition of metals, and the design of heterojunctions, to further boost photocatalytic activity. In particular, the utilization of kaolinite, montmorillonite, attapulgite, and sepiolite as clay mineral supports for photocatalysts is discussed in detail, showcasing their potential in wastewater treatment. The review underscores the significant strides made in the development of clay mineral-based photocatalysts, highlighting their effectiveness in degrading organic contaminants under light exposure. Nevertheless, there are persisting challenges such as the optimization of loading quantities, improvement in compatibility between clay minerals and photocatalysts, and reduction in preparation costs for large-scale applications. In summary, this review offers valuable insights into the current status of clay mineral-based photocatalysts for water purification, thereby stimulating future research in this promising field. [ABSTRACT FROM AUTHOR]

Cerussite is an essential lead oxide mineral with increasing economic importance as lead sulfide resources deplete. This study utilizes density functional theory (DFT) to investigate the structural and electronic properties of the sulfurized cerussite (110) surface. The results show that when the cerussite crystal cleaves along the (110) plane, only the surface layer atoms undergo relaxation to reconstruct the surface, while the atoms located deeper have almost no impact on the reconstructed surface structure. The Pb atoms on the cerussite (110) surface react with the sulfurizing agent to form a PbS deposition layer with a structure similar to galena. This PbS deposition layer is tightly adsorbed onto the lead oxide layer through Pb-S bonds formed by S and subsurface lead oxide structure Pb atoms. The chemical reactivity of Pb atoms in the PbS layer on the sulfurized cerussite (110) surface is more potent than that of Pb atoms on the galena surface; additionally, the Pb atoms closer to the lead oxide layer exhibit slightly higher chemical reactivity than those farther away. This study provides insight into sulfurized cerussite surfaces' structure and properties at an atomic level and assists in explaining the floating behavior of cerussite. [ABSTRACT FROM AUTHOR]

One of the most challenging problems for people around the world is the lack of clean water. In the past few decades, the massive discharge of emerging organic pollutants (EOPs) into natural water bodies has exacerbated this crisis. Considerable research efforts have been devoted to removing these EOPs due to their biotoxicity at low concentrations. Heterogeneous photocatalysis via coupling clay minerals with nanostructured semiconductors has proven to be an economical, efficient, and environmentally friendly technology for the elimination of EOPs in drinking water and watershed water. Natural zeolite minerals (especially clinoptilolites) are regarded as appropriate supports for semiconductor-based photocatalysts due to their characteristics of having a low cost, environmental friendliness, easy availability, co-catalysis, etc. This review summarizes the latest research on clinoptilolites used as supports to prepare binary and ternary metal oxide or sulfide semiconductor-based hybrid photocatalysts. Various preparation methods of the composite photocatalysts and their degradation efficiencies for the target contaminants are introduced. It is found that the good catalytic activity of the composite photocatalyst could be attributed to the synergistic effect of combining the clinoptilolite adsorbent with the semiconductor catalyst in the heterogeneous system, which could endow the composites with an excellent adsorption capacity and produce more e−/h+ pairs under suitable light irradiation. Finally, we highlight the serious threat of EOPs to the ecological environment and propose the current challenges and limitations, before putting the zeolite mineral composite photocatalysts into practice. The present work would provide a theoretical basis and scientific support for the application of zeolite-based photocatalysts for degrading EOPs. [ABSTRACT FROM AUTHOR]