eprintid: 10194590 rev_number: 8 eprint_status: archive userid: 699 dir: disk0/10/19/45/90 datestamp: 2024-07-16 13:38:27 lastmod: 2024-07-16 13:38:27 status_changed: 2024-07-16 13:38:27 type: article metadata_visibility: show sword_depositor: 699 creators_name: Büchner, Carina creators_name: Kubitza, Niels creators_name: Malik, Ali M creators_name: Jamboretz, John creators_name: Riaz, Aysha A creators_name: Zhu, Yujiang creators_name: Schlueter, Christoph creators_name: McCartney, Martha R creators_name: Smith, David J creators_name: Regoutz, Anna creators_name: Rohrer, Jochen creators_name: Birkel, Christina S title: Chemical Conversions within the Mo–Ga–C System: Layered Solids with Variable Ga Content ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F56 note: This version is the author-accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. abstract: Layered carbides are fascinating compounds due to their enormous structural and chemical diversity, as well as their potential to possess useful and tunable functional properties. Their preparation, however, is challenging and forces synthesis scientists to develop creative and innovative strategies to access high-quality materials. One unique compound among carbides is Mo₂Ga₂C. Its structure is related to the large and steadily growing family of 211 MAX phases that crystallize in a hexagonal structure (space group P6₃/mmc) with alternating layers of edge-sharing M₆X octahedra and layers of the A-element. Mo₂Ga₂C also crystallizes in the same space group, with the difference that the A-element layer is occupied by two A-elements, here Ga, that sit right on top of each other (hence named “221” compound). Here, we propose that the Ga content in this compound is variable between 2:2, 2:1, and 2: ≤1 (and 2:0) Mo/Ga ratios. We demonstrate that one Ga layer can be selectively removed from Mo₂Ga₂C without jeopardizing the hexagonal P6₃/mmc structure. This is realized by chemical treatment of the 221 phase Mo₂Ga₂C with a Lewis acid, leading to the “conventional” 211 MAX phase Mo₂GaC. Upon further reaction with CuCl₂, more Ga is removed and replaced with Cu (instead of fully exfoliating into the Ga-free Mo₂CTx MXene), leading to Mo₂Ga₁₋ₓCuₓC still crystallizing with space group P6₃/mmc, however, with a significantly larger c-lattice parameter. Furthermore, 211 Mo₂GaC can be reacted with Ga to recover the initial 221 Mo₂Ga₂C. All three reaction pathways have not been reported previously and are supported by powder X-ray diffraction (PXRD), electron microscopy, X-ray spectroscopy, and density functional theory (DFT) calculations. date: 2024-04-29 date_type: published publisher: RSC official_url: https://doi.org/10.1021/acs.inorgchem.4c00107 full_text_type: other language: eng verified: verified_manual elements_id: 2269871 doi: 10.1021/acs.inorgchem.4c00107 medium: Print-Electronic lyricists_name: Regoutz, Anna lyricists_id: AREGO48 actors_name: Regoutz, Anna actors_id: AREGO48 actors_role: owner funding_acknowledgements: NNCI-ECCS-1542160 [University College London]; I-20221270 [University College London]; NHR4CES [University College London]; [Federal Ministry of Education and Research] full_text_status: restricted publication: Inorganic Chemistry volume: 63 number: 17 pagerange: 7725-7734 pages: 10 event_location: United States issn: 2052-1553 citation: Büchner, Carina; Kubitza, Niels; Malik, Ali M; Jamboretz, John; Riaz, Aysha A; Zhu, Yujiang; Schlueter, Christoph; ... Birkel, Christina S; + view all <#> Büchner, Carina; Kubitza, Niels; Malik, Ali M; Jamboretz, John; Riaz, Aysha A; Zhu, Yujiang; Schlueter, Christoph; McCartney, Martha R; Smith, David J; Regoutz, Anna; Rohrer, Jochen; Birkel, Christina S; - view fewer <#> (2024) Chemical Conversions within the Mo–Ga–C System: Layered Solids with Variable Ga Content. Inorganic Chemistry , 63 (17) pp. 7725-7734. 10.1021/acs.inorgchem.4c00107 <https://doi.org/10.1021/acs.inorgchem.4c00107>. document_url: https://discovery.ucl.ac.uk/id/eprint/10194590/1/Mo2Ga2C_Birkel_rev.pdf