Periodic Reporting for period 2 - THEIA (Design and engineering of porous nitride-based materials as a platform for CO2 photoreduction)
Berichtszeitraum: 2021-08-01 bis 2023-01-31
Problem addressed and importance: Reshaping our energy portfolio considering the sustainability of global energy resources is central to the European Energy Roadmap 2050. Hence, researchers need to identify efficient routes towards solar fuels production. Unlike H2 evolution, CO2 photoreduction has been poorly studied. Given the scope for CO2 utilisation in a carbon-constrained future, there is an exciting opportunity to devote targeted research towards CO2 photoreduction. Photocatalysis is one route towards CO2 reduction. Yet, the design of a cost-effective, sustainable, efficient and robust photocatalyst remains a highly challenging task.
Proposed project and objectives: In this project, we merge catalysis, materials science and engineering to develop a radically new class of photocatalysts, i.e. porous boron nitride (BN)-based materials for CO2 reduction. Our approach is opposite to many research trends which explore crystalline and non-porous materials. Doing this, we aim to compete with the 40-year old benchmark in the field, TiO2. Porous BN combines key attributes for CO2 photoreduction: (i) chemical, structural and optoelectronic tunability, (ii) high porosity, (iii) semi-crystalline to amorphous nature. These features provide unique pathways towards effective sorption of reactants/products, facile band gap engineering, and enhanced surface charge transfer. Their semi-crystalline to amorphous nature may facilitate scale-up. To carry out this project, we are working towards three objectives:
- Objective 1. Creating a porous BN-based material platform with adsorptive and photocatalytic functionalities
- Objective 2. Adding a new dimension to photocatalyst design via porosity control
- Objective 3. Creating approaches to molecular- and micro-structure engineering in porous BN
Proposed project and objectives: In this project, we merge catalysis, materials science and engineering to develop a radically new class of photocatalysts, i.e. porous boron nitride (BN)-based materials for CO2 reduction. Our approach is opposite to many research trends which explore crystalline and non-porous materials. Doing this, we aim to compete with the 40-year old benchmark in the field, TiO2. Porous BN combines key attributes for CO2 photoreduction: (i) chemical, structural and optoelectronic tunability, (ii) high porosity, (iii) semi-crystalline to amorphous nature. These features provide unique pathways towards effective sorption of reactants/products, facile band gap engineering, and enhanced surface charge transfer. Their semi-crystalline to amorphous nature may facilitate scale-up. To carry out this project, we are working towards three objectives:
- Objective 1. Creating a porous BN-based material platform with adsorptive and photocatalytic functionalities
- Objective 2. Adding a new dimension to photocatalyst design via porosity control
- Objective 3. Creating approaches to molecular- and micro-structure engineering in porous BN
Since the start of the project, we have worked mainly towards Objectives 1 and 2, mentioned above, with greater emphasis on Objective 1. We provide further details below.
- Objective 1. Creating a porous BN-based material platform with adsorptive and photocatalytic functionalities. Here, we have focused on designing, synthesising, characterising and testing porous boron nitride doped with various elements. These elements include O, Cu, P and S. For the former three elements, we have shown how doping can enhance the sorptive and optoelectronic properties of the material. The impact on the CO2 conversion depends on the doping with positive effects seen with Cu and O and negative ones with P. In the case of S, we could not dope to a sufficiently high level to qualitatively and quantitatively confirm doping.
- Objective 2. Adding a new dimension to photocatalyst design via porosity control. Here, we are aiming to synthesise porous boron nitride samples with tunable porosity but similar chemical composition. The rationale is that we are exploring the effect of porosity on photocatalytic performance in the context of CO2 conversion. Characterisation and testing is still on-going.
- Objective 1. Creating a porous BN-based material platform with adsorptive and photocatalytic functionalities. Here, we have focused on designing, synthesising, characterising and testing porous boron nitride doped with various elements. These elements include O, Cu, P and S. For the former three elements, we have shown how doping can enhance the sorptive and optoelectronic properties of the material. The impact on the CO2 conversion depends on the doping with positive effects seen with Cu and O and negative ones with P. In the case of S, we could not dope to a sufficiently high level to qualitatively and quantitatively confirm doping.
- Objective 2. Adding a new dimension to photocatalyst design via porosity control. Here, we are aiming to synthesise porous boron nitride samples with tunable porosity but similar chemical composition. The rationale is that we are exploring the effect of porosity on photocatalytic performance in the context of CO2 conversion. Characterisation and testing is still on-going.
Progress beyond the state of the art: The investigations described above correspond to the first attempts to experimentally dope porous boron nitride with such elements and test its CO2 photoconversion performance. From these studies, we are able to generate new knowledge on the structure-property relationships for porous boron nitride based materials and have so far published 3 research articles on the topic.
Expected results until end of the project: We expect to complete Objective 1 in the next 12 months and Objective 2 in the next 24 months. We will start Objective 3 in the next year. At the end of the project, we envision the collective knowledge generated will provide an understanding of the complex interplay between optical band gap, charge carrier dynamics, excited state life-time, and physical and chemical properties such as porosity, functionalities and vacancies for porous boron nitride based materials.
Expected results until end of the project: We expect to complete Objective 1 in the next 12 months and Objective 2 in the next 24 months. We will start Objective 3 in the next year. At the end of the project, we envision the collective knowledge generated will provide an understanding of the complex interplay between optical band gap, charge carrier dynamics, excited state life-time, and physical and chemical properties such as porosity, functionalities and vacancies for porous boron nitride based materials.