MXene-semiconductor composites for hydrogen production by photocatalytic water splitting reaction
Project Director: Dr. Stefan NEATU
Project ID: PN-III-P4-PCE-2021-1461 / MAXIM
Project coordinator: Dr. Ștefan Neațu
Project type: National
Project Program: PCE
Funded by: Romanian National Authority for Scientific Research, UEFISCDI
Contractor: National Institute of Materials Physics
Converting solar energy into clean energy, such as hydrogen energy, is admitted as one of the most effective approaches to resolve the energy problem, in this regard, photocatalysis being considered as a spearhead of such an approach. The major hurdle that needs to be overcome in this area however is the recombination of photogenerated electrons and holes. In this regard, the combination of MXenes with various semiconductor photocatalysts led to a marked increase in photoactivity. In this view, through this project, we aim to develop new photocatalytic systems that comprise the use of i-MXene-semiconductor composites for hydrogen production by photocatalytic water splitting reaction. The project approach is to develop operational powder composites based on i-MXene and stable and active semiconductor photocatalyst materials, which should be able in the end to perform easily the hydrogen evolution reaction on their surface. The originality of this project stands in the enrichment of current knowledge in the field of hydrogen evolution reaction by photocatalytic water splitting. It has to be underlined that, currently there is no studies published in the literature comprising the use i-MXene as co-catalysts for this application.
The main MAXIM’s goal is to develop new photocatalytic systems based on 2D layered i-MXenes for photocatalytic water splitting. The derived specific objectives of the MAXIM project are:
O1. Design and optimization of the synthesis of active photocatalytic systems based on i-MXenes.
O2. Achievement of high apparent quantum efficiencies for hydrogen production through water splitting.
O3. Insights in the reaction mechanism based on the correlations of material characteristics with their photocatalytic performances. A special focus will be devoted to the use of in situ studies, paying particular attention to the study of the mechanism of hydrogen production through water splitting and electrons movement, as well as to the regeneration of active sites.
The proposal aims to expand the existing knowledge in the field of hydrogen production through photocatalytic water splitting reaction by introducing new approaches to improve the development of new MXene-based composite able to directly convert the light into energy stored in chemicals, a hot topic of these days. Thus, the estimated results of the project are:
- Methods for the preparation of photocatalytic composites based on i-MXenes;
- Thermal and oxidative stability of the photocatalytic composites based on i-MXenes;
- Morphology of surfaces and textural properties;
- Optimal synthesis method and reproducibility of the synthesis method;
- Photocatalytic performance and conditions for efficient realization of the water splitting reaction with hydrogen production;
- Optical, vibrational and structural properties of i-MXenes-based composites;
- The key characteristics of i-MXenes-based composites that influence photoactivity;
- The mechanism of the water splitting reaction on i-MXenes-based composites;
- Publication of at least two articles in high-impact journals (greater than 6);
- Participation in international conferences (at least two participations / year);
- 1 patent application.
Project coordinator: Dr. Ștefan Neațu - Senior researcher II
Dr. Florentina Neațu - Senior researcher I
Dr. Mihaela Mirela Trandafir - Senior researcher III
Dr. Anca Coman - Senior researcher
Drd. Maria-Iuliana Chirică - Assistant researcher
Dr. Andrei Cristian Kuncser - Senior researcher III
Drd. Alexandra Corina Iacoban - Assistant researcher
Within this stage, the following research activities were foreseen: 1) Synthesis of i-MXenes starting from i-MAX phases; 2) Synthesis of composites based on i-MXene. Ensuring the stability of these composites; 3) Characterization of MXene-based composites by investigating thermal, oxidative, morphological and textural properties. Determination of structural properties; 4) Verification of the photoactivity of i-MXene-based composites. Ensuring good photocatalytic results by adding small amounts of noble metal (Pt, Pd, etc.); and 5) Dissemination of results.
Starting from experimental data present in the specialized literature, in this first stage of the project several i-MAX phases of the type Mo2/3Y1/3AlC and (W2/3Sc1/3)2AlC were prepared. Starting from these parent i-MAX phases, we moved on to the synthesis of i-MXenes of the Mo1.33C type, materials that were further used to obtain i-MXene/TiO2 composites by applying a hydrothermal approach. The composites were characterized using several types of characterization techniques, and their photocatalytic performance was verified in the production of H2 through the water splitting reaction. The best performing composite generates a hydrogen production rate of over 500 µmol g–1 h–1, which is among the highest values reported in the literature on MXene-based photocatalysts. The obtained results open new opportunities in the preparation of highly active materials for the production of H2 through the photocatalytic water splitting reaction.
The objectives were fully met. The detailed results can be found in the scientific report submitted to the Contracting Authority.
Ștefan NEAȚU, Doctor in the field of Chemistry
Senior researcher II
Department: Laboratory of Catalytic Materials and Catalysis
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