Metallated Graphynes as a New Class of Photofunctional 2D Organometallic Nanosheets

Abstract

Tw o-dimensional (2D) nanomaterials are attracting mucha ttention due to their excellent electronic and optical properties.H ere,w er eport the first experimental preparation of two free-standing mercurated graphyne nanosheets via the interface-assisted bottom-up method, which integrates both the advantages of metal center and graphyne.T he continuous large-area nanosheets derived from the chemical growth show the layered molecular structural arrangement, controllable thickness and enhanced p-conjugation, whichr esult in their stable and outstanding broadband nonlinear saturable absorption (SA) properties (at both 532 and 1064 nm). The passively Q-switched (PQS) performances of these two nanosheets as the saturable absorbers are comparable to or higher than those of the state-of-the-art 2D nanomaterials (suchasgraphene,black phosphorus,MoS 2 , g-graphyne,etc.). Our results illustrate that the two metallated graphynes could act not only as anew class of 2D carbon-richmaterials,but also as inexpensive and easily available optoelectronic materials for device fabrication.

Metalloporphyrin-Linked Mercurated Graphynes for Ultrastable CO2 Electroreduction to CO with Nearly 100% Selectivity at a Current Density of 1.2 A cm–2

“…From Figures S15 and S16, the almost complete disappearance of the −CCH signal from H 2 TPP and CoTPP, and the appearance of a new characteristic signal of −CC– (∼2100 vs 2140 cm –1 ) from Hg-H 2 TPP and Hg-CoTPP confirm the successful formation of the −CC–Hg–CC– fragment in the structures. The residual weak signal of −CCH in the Hg-H 2 TPP and Hg-CoTPP nanosheets corresponds to the little uncondensed acetylene groups at the edges/termini . A broad peak of the −NH– group is also observed for both H 2 TPP and Hg-H 2 TPP nanosheets.…”

“…There is no residual −NH– stretch for both CoTPP and Hg-CoTPP, as also confirmed by 1 H and 13 C NMR and/or matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) high-resolution mass spectrometry (HRMS) of H 2 TPP and CoTPP, which demonstrates the successful coordination of N to Co atoms (Figures S99 and S100). The 13 C CP-MAS NMR spectral data of Hg-H 2 TPP and Hg-CoTPP bulks confirm the chemical structures of the backbone with a characteristic chemical shift of C–Hg at about 100–110 ppm, , along with the characteristic chemical shifts attributed to the porphyrin and triple bond units (Figure S17). While the peaks of the 13 C CP-MAS NMR spectrum from Hg-CoTPP bulks are not very clear as compared to those of Hg-H 2 TPP, we can still distinguish the characteristic peaks between them (Figure b).…”

“…As inspired by the high hydrogen evolution overpotential of mercury (Hg) and the pioneering study on 2D mercurated graphynes, a series of novel metalloporphyrin-linked mercurated graphyne nanosheets (Hg-MTPP, M = Mn, Fe, Co, Ni, Cu, and Zn) were designed and synthesized, in which the mercurated graphyne was used as the building block to connect the metalloporphyrin units. Density functional theory (DFT) calculations in this work support the fact that the metal (M) center of the metalloporphyrin ring in Hg-MTPP is presumed to act as the active site for the electroreduction of CO 2 to CO.…”

Switching the Nonlinear Optical Absorption of Titanium Carbide MXene by Modulation of the Surface Terminations

“…NLO absorption refers to a phenomenon in which the absorption coefficient of materials differs under low- and high-irradiance light. High-performance NLO absorption materials are desirable for pulse-laser generation (mode locking or Q-switching), optical limiting, multiphoton-pumped lasing, sub-bandgap photodetection, etc . Among the possible NLO materials, two-dimensional (2D) materials are of particular promise because of certain advantages, viz.…”

Antimony Sulfide Nanosheets with Size-Dependent Nonlinear Optical Properties for Q-Switched Pulse Applications

“…Nonlinear optics describes the unique interactions of light and matter and has become the basis of many key techniques in modern optoelectronics. − Nonlinear optical (NLO) materials have enabled various photonic devices such as pulsed lasers, − optical modulators, and laser protection devices. − NLO materials with saturable absorption, in which the absorbance decreases with increasing laser intensity, are used to fabricate saturable absorbers (SAs) in resonant cavities to produce ultrashort laser pulses with ultrashort and high peak power, which are widely applied in advanced molecular spectroscopy, micromachining, biology, and medicine . Organic dyes have been eliminated as SAs due to their short lifetimes, high toxicity, and poor light stability.…”