Interlayer Coordination of Pd–Pd Units in Exfoliated Black Phosphorus

Abstract

The chemical functionalization of 2D exfoliated black phosphorus (2D BP) continues to attract great interest, although a satisfactory structural characterization of the functionalized material has seldom been achieved. Herein, we provide the first complete structural characterization of 2D BP functionalized with rare discrete Pd 2 units, obtained through a mild decomposition of the organometallic dimeric precursor [Pd(η 3 -C 3 H 5 )Cl] 2 . A multitechnique approach, including HAADF-STEM, solid-state NMR, XPS, and XAS, was used to study in detail the morphology of the palladated nanosheets (Pd 2 /BP) and to unravel the coordination of Pd 2 units to phosphorus atoms of 2D BP. In particular, XAS, backed up by DFT modeling, revealed the existence of unprecedented interlayer Pd−Pd units, sandwiched between stacked BP layers. The preliminary application of Pd 2 /BP as a catalyst for the hydrogen evolution reaction (HER) in acidic medium highlighted an activity increase due to the presence of Pd 2 units.

Rapid Melt‐Quenching Enables General Synthesis of High‐Loading Single‐Atom Catalysts with Bicontinuous Nanoporous Structure

“…This is evidenced by the decrease of white line intensity (Ir) or the negative-shift of absorptionedge (Ru, Pd, and Rh) of SACs in comparison with corresponding precursors in the XANES spectra (Figure S33, Supporting Information). [7,8,11] The analyses of electronic state of noble-metal atoms by XPS also support the above view (Figures S34-S37, Supporting Information). Furthermore, the atomic structure of these SACs was investigated by EXAFS spectra (Figure 3d-g).…”

“…[1,2] Due to this exciting feature, single-atom catalysts (SACs) show unconventional catalytic activities in comparison with bulk or nano catalysts, which sparked the development of general synthetic strategies of SACs. [2][3][4][5][6][7] Recent advances in synthetic strategies of SACs are usually dominated by bottom-up approaches which always need meticulous design and synthesis, [2] such as defect engineering, [8] spatial confinement, [9][10][11] and coordination design strategies. [12,13] High-temperature synthesis strategies, as a typical top-down method, [6,[14][15][16][17] exhibited a great potential for the scalable nanomanufacturing of SACs.…”

Chemically functionalized phosphorenes and their use in the water splitting reaction

“…Noble metals such as dipallada unit (Pd 2 ) have been sandwiched between phosphorene sheets. 64 The extended X-ray absorption fine structure (EXAFS) analysis and the DFT modelling have highlighted that the coordination of Pd 2 occurs between the layer, bridging two phosphorene sheets.…”

Reaction Chemistry at Discrete Organometallic Fragments on Black Phosphorus

“…A report that employs a more versatile synthetic approach utilizes an organometallic precursor, [Pd(η 3 -C 3 H 5 )Cl] 2 , to intercalate discrete Pd 2 units into bP, creating an effective catalyst for hydrogen evolution. [22] Such molecular methods hold extraordinary synthetic potential, as they leverage decades of knowledge in homogeneous phosphine chemistry and utilize mild and accessible reaction conditions. Yet, metallation of bP using molecular reagents remains little explored, [23][24][25][26][27][28][29][30] and evidence of direct metal-tophosphorus bonding in the resulting materials is rare.…”