Hidróxidos duplos lamelares e derivados como materiais multifuncionais para processos de adsorção, fotocatálise e energia limpa

Abstract

This thesis investigates the development and application of layered double hydroxides (LDHs) and their derivatives, mixed metal oxides (MMOs), as multifunctional materials aimed at environmental remediation and clean energy production. The research was structured in interconnected chapters, ranging from a systematic literature review to the experimental evaluation of the synthesized materials. The systematic review revealed a growing interest in LDHs and MMOs for adsorption, photocatalysis, and photocatalytic hydrogen production processes, highlighting limitations related to efficiency, stability, and action mechanisms. Based on these challenges, bimetallic (CoAl and NiAl) and trimetallic (NiCoAl) systems were synthesized, along with their calcined derivatives, which were extensively characterized in terms of their structural, morphological, textural, and electronic properties. The results demonstrated that CoAl-LDH exhibited a high adsorption capacity for naproxen, with rapid kinetics influenced by parameters such as pH, initial concentration, and temperature. The process was well described by kinetic and isothermal models, indicating a predominance of chemical and electrostatic interactions. In the energy context, NiAl-LDH and CoAl-LDH showed photocatalytic activity for hydrogen production via water splitting, highlighting the influence of metallic composition on charge separation and process efficiency. Furthermore, mixed metal oxides, particularly the trimetallic NiCoAl-MMO system, exhibited high performance in the photodegradation of ciprofloxacin, with effective removal under different operating conditions and evidence of mechanisms mediated by reactive species. Overall, the results reveal a direct relationship between composition, structure, and functional performance, demonstrating that modulation between lamellar phases and derived oxides is a promising strategy for the development of multifunctional materials. Thus, this thesis contributes significantly to scientific advancement in the area of materials applied to environmental remediation and clean energy generation, offering perspectives for sustainable applications in the real world.