“Engineering of Titanium Suboxide architectures for Photocatalytic Upcycling of CO₂ into Chemical Feedstock with Comprehensive Mechanistic Investigation”

• Applicant: Dr. Surendra Saini
• Subject Area: Synthesis and Properties of Functional Materials ; Organic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 568486797

The core thrust of the project is to develop unique three-dimensional (3D) titanium suboxide (TSO)-based photocatalysts for the photoreduction of CO2 into chemical feedstock, supported by a comprehensive mechanistic understanding of interfacial band-gap structures, surface bonding states, and charge carrier dynamics. The 3D TSO-based photocatalysts will be engineered through oxygen defect manipulation, band gap tuning, and copper incorporation (particularly using single atoms and core-shell structures), with a specific emphasis on mechanisms affecting stability, interfacial interactions, surface redox kinetics, charge separation, charge recombination, selectivity and apparent quantum yield. Gaining such insights is crucial for constructing efficient photocatalytic systems for multi-electron redox transformations in CO2 reduction, where reaction rates must surpass charge recombination rates. The project seeks to enhance CO2 reduction selectivity for industrial applications by strategically adjusting the redox potentials of TSO-based photocatalysts and optimizing photon utilization through advanced catalyst support and reactor design and improved mass transfer along the light trajectory. Additionally, the proposal will investigate new reaction engineering aspects of the CO2 photoreduction process, leveraging the expertise of Prof. Ulrich Ulmer’s group. Beyond essential catalyst thermodynamic potentials, product selectivity will be governed by reaction kinetics-refined via controlled CO2 concentration, H2 concentration, light intensity, adsorption characteristics, and electron/hole transfer efficiency. Ultimately, this project seeks to establish a knowledge-based framework for designing effective TSO-based photocatalytic architectures with high rectifying behavior for the conversion of CO2 into mono-carbon and multi-carbon chemical entities. It will involve operando and post-mortem investigations of model photocatalysts and extensive photophysical characterization of light-induced electron transfer processes across various redox states. The expected outcomes are anticipated to advance the fundamental understanding of the advantages and limitations of TSO-based architectures for CO2 photoreduction and provide unprecedented design principles for creating new visible light-responsive TSO-based architectures.

• DFG Programme: WBP Position