Sustainable Chemistry

The development of sustainable methodologies for the synthesis of organic compounds is a fundamental challenge in modern organic chemistry. This project is focused on advancing the fields of photoredox catalysis (PRC) and synthetic photoelectrochemistry, exploring their applications in oxidative C-H substitution reactions.

In recent years, there has been a significant increase in textile production and, consequently, in the generation of waste. In Brazil alone, approximately 175,000 tons of this type of waste are generated, of which only 36,000 tons are reused. In this context, this work aimed to use textile waste as a base for conversion into conductive materials, adding value to a discarded material.

Graphitic carbon nitride is a semiconducting material of a graphite-like 2D layered structure. It is well known for its photocatalytic properties, which can be exploited for solar-light-driven water splitting and degradation of organic pollutants. Here, we report its capabilities of catalyzing the reduction of the azo bond by hydrazine to two amines under visible light. This photocatalytic reaction provides a novel, appealing way to reduce azo dye wastes as pollutants other than degradation.

Our growing population, development, and increasing energy demands will strain the environment in the coming decades, necessitating breakthroughs in sustainable energy generation and storage. State-of-the-art lithium-ion batteries face significant challenges, including limited lithium resources, safety issues, and electrochemical performance nearing theoretical limits. Novel rechargeable batteries, such as magnesium-ion batteries, present promising alternatives due to their material abundance and improved safety.

The widespread use of synthetic dyes has led to the release of substantial amounts of dye-contaminated wastewater, posing significant environmental and health concerns. This study focuses on the use of anodic and electrochemically activated persulfate oxidation for the degradation of organic contaminants. Specifically, the structural variations of nine dyes in the indigoid and azo families, and their impact on the efficiency of electrochemical oxidation were analyzed. An in situ continuous monitoring apparatus with a UV-visible detector was employed to collect data in real-time.

Polymeric membranes have gained considerable interest in both the scientific and industrial communities due to their wide range of applications. This technology has emerged as a cost-effective and environmentally friendly alternative for gas separation. A polymeric material for gas separation applications must exhibit high permeability and selectivity for one of the components in the mixture. Therefore, the development of new materials with high performance in gas separation involves finding a balance between these two parameters.

The textile industry is one of the most water-intensive sectors, primarily attributed to the substantial amount of water required for dyeing. During dyeing, wastewater containing synthetic dyes and auxiliary chemicals is produced, underscoring the need for more sustainable dyeing methods to address environmental concerns such as the release of pollutants. Supercritical carbon dioxide (scCO2) dyeing is an attractive sustainable method, as it is zero-water and zero-effluent.

Advancements in photocatalysis have transformed synthetic organic chemistry, using light as a powerful tool to drive selective chemical transformations.

The innovation in this study lies in enhancing conventional sensors through the integration of advanced materials such as graphene and its derivatives. These materials, derived from carbon, a widely abundant, renewable, and sustainable element, exhibit exceptional properties, including high molecular adsorption capacity, superior electrical conductivity, and remarkable mechanical strength. Their multifunctionality not only enhances sensor performance but also promotes material efficiency by significantly reducing the resources required for production.