Toward a Greener Production of Materials: Water‐Minimized Synthesis of NiAl‐, NiFe‐, and CoAl‐Layered Double Hydroxides for Photocatalytic CO ₂ Reduction

Conventional methods of synthesis of materials generate a large amount of waste owing to the extensive use of solvents and auxiliary agents. Particularly, this is relevant for the production of bulk catalysts and supports, such as layered double hydroxides (LDHs), where the development of greener technologies is desired. In this work, it is reported a water‐minimized synthesis of NiAl, NiFe, and CoAl LDHs using resonant acoustic mixing is reported, allowing a homogeneous dispersion of the precursors in the final materials. The prepared solids exhibited variable crystallinity and successful incorporation of the chosen metal species into the final structure. Additionally, the electronic and optical properties of these solids were found to be strongly dependent on the conditions of the synthesis and can be tuned by the appropriate parameter selection. The application of the prepared materials on the photocatalytic reduction of CO ₂ was assessed, showing activity for all the samples, as well as a strong dependence between their physicochemical properties and catalytic performance. This approach offers a scalable and environmentally friendly alternative for the preparation of bulk catalytic materials.