The JANUS BI project has made significant technical and scientific advancements during its initial period, achieving key milestones across its objectives.
In Objective 1, the development of a scalable protocol for Janus 2D materials, the team successfully synthesized a library of functionalizing agents, including polymers, inorganic nanocrystals, and carbon dots, designed to selectively adhere to specific faces of 2D materials. The exfoliation of transition metal dichalcogenides (TMDs) such as MoS2 was optimized using both mechanical and chemical approaches, leading to the production of the 1T-phase, a highly conductive variant, via pre-treatment with n-butyllithium. The first fully asymmetric decoration was achieved for a BiOBr/MoS2 heterostructure, with experimental and theoretical analyses confirming a preferential alignment of layers. Advanced characterization methods such as high-resolution TEM, Raman spectroscopy, and photoelectrochemistry and X-ray diffraction were instrumental in validating the structural and functional properties of these heterostructures. Stability in solution-processed inks was achieved enabling high throughput ultrasonic spray coating (see below).
Objective 2 saw progress in processing and assembling Janus 2D materials into solid-state structures, with a focus on thin-film deposition and the development of porous architectures. Using ultrasonic spray-coating, the team demonstrated precise control over film thickness and homogeneity. Preliminary studies also explored the integration of symmetric MoS2 nanosheets into hydrogel matrices to investigate hierarchical structures. These efforts provide foundational insights for fabricating functional interfaces tailored for light-energy conversion.
In Objective 3, the project advanced functionality testing of Janus 2D heterostructures for light-conversion and catalytic applications. The BiOBr/MoS2 junction, classified as a type-II heterojunction, exhibited efficient photo-induced charge transfer, supported by photoluminescence quenching and bandgap reduction. Early testing of photo(electro)catalytic systems demonstrated promising activity in hydrogen evolution reactions, with results documented in two publications. Additional work is underway to study hybrids of MoS2 with CuO and AgBiS2, expanding the library of functional materials.
Overall, these activities establish JANUS BI as a frontrunner in the development of asymmetrically functionalized 2D materials, highlighting their potential for energy conversion technologies and other advanced applications. The outcomes lay a robust foundation for further exploration and scalability, driving innovation in nanochemistry and materials science.
