Development of bijels derived from Prussian blue and its analogues for use as electrodes

• Grant number: 24/19156-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2025
• End date: June 30, 2028
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Denise Freitas Siqueira Petri
• Grantee: João Victor Mattioni
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Bicontinuous interfacially jammed emulsion gels (bijels) represent an innovative platform for the development of functional materials. However, traditional stabilization employs silica nanoparticles, with few studies on the use of electroactive nanoparticles. This project proposes the study of bijel stabilization using Prussian Blue nanoparticles and their analogs (PBAs), aiming not only to optimize colloidal stability but also to explore their potential as catalytic electrodes in water splitting reactions.A key challenge of this study is the controlled stabilization of bijels with PBA nanoparticles, which require specific surface modifications to ensure interfacial affinity. Chemical functionalization strategies, including polymer coatings and surfactant adsorption, will be explored to optimize the hydrophobicity and surface charge of PBAs and ensure their effective positioning at the water-oil interface. It is important to note that the oil phase contains photoreactive monomers and initiators. The systems demonstrating the highest interfacial stability will undergo photopolymerization, resulting in three-dimensional porous structures, which will be subsequently evaluated for their electrocatalytic performance.The main objectives of this research are: (i) to synthesize and characterize PBA nanoparticles with controlled size and surface properties; (ii) to develop stable bijels using modified PBAs; (iii) to fabricate and characterize bijel-based electrodes; and (iv) to evaluate their electrochemical performance in oxygen evolution (OER) and hydrogen evolution (HER) reactions under different pH conditions. The aim is to achieve overpotentials lower than 250 mV for OER and 120 mV for HER, surpassing the efficiency of current non-noble metal-based catalysts. It is expected to develop hierarchically structured electrocatalysts with enhanced stability and high catalytic performance. The successful implementation of this approach may lead to scalable and sustainable hydrogen production. (AU)