RESUMO
Silver cluster-assembled materials (SCAMs), by virtue of their tunable structure, accessible surface area and excellent stability, hold great promise as highly efficient catalysts. Herein, we report a new SCAM [Ag12(StBu)6(CF3COO)3(TPyP)]n (denoted as Ag12TPyP) composed of a Ag12 chalcogenolate cluster core stabilized by porphyrinic ligands. Ag12TPyP showed superior sulfur mustard simulant (2-chloroethyl ethyl sulfide, CEES) degradation efficiency and achieved a half lifetime (t1/2) of 1.5 min with 100% selectivity. The experimental results demonstrated that synergistic effects between the silver cluster and photosensitizer ligand promote the efficiency of the generation of singlet oxygen (1O2), which accelerates the decontamination rate. Additionally, benefiting from strong affinity between the silver cluster and CEES, Ag12TPyP exhibits a CEES uptake of 74.2 mg g-1. This work demonstrates that SCAMs offer a new route to the rational design of novel materials for the detoxification of mustard gas.
RESUMO
Based on first-principles calculations, we present a systematic investigation of the electronic and magnetic properties of armchair phosphorene nanoribbons (APNRs) functionalized by 3d transition metal (TM) atoms. We found that the central hollow site is the most favorable adsorption site for Mn, Co and Ni, while Fe preferentially occupies the edge hollow site. All of the TM atoms bind to the adjacent P and their adsorption energies are in the range of -4.29 eV to -1.59 eV. Meanwhile, the large ratio of the adsorption energy to the cohesive energy of the metal bulk phase indicates that TM atoms have a preferred 2D growth mode on the edge hydrogenated armchair phosphorene nanoribbons (H-APNRs). The magnetic moments reduce by about 2-4 µB, relative to their free atom states, depending on whether the TM atom is in the high-spin or low-spin state. This reduction is mainly attributed to the electrons transferring from the high-level TM 4s shell to the low-lying 3d shell. Our results demonstrate that TM atom adsorption is a feasible approach to functionalizing the H-APNRs chemically, which results in peculiar electronic and magnetic properties for potential applications in nano-electronics and spintronics.
RESUMO
Motivated by recent experimental developments of graphitic-CN (g-CN) sheets, we investigate the suitability of hydrogen storage on Li decorated g-CN via first-principles calculations. We find that the binding energies of Li atoms are very large, ranging from 2.70 to 4.73 eV, which are significantly higher than the cohesive energy of bulk Li. Lithium atoms therefore tend to form 2D rather than 3D patterns on g-CN, promoting reversible hydrogen adsorption and desorption. Remarkably, the average adsorption energy of H2 molecules falls in the 0.14-0.23 eV range, and the Li decorated CN shows a high theoretical gravimetric density of 10.81 wt%, which is favorable for massive hydrogen storage. Our results suggest that the Li decorated CN could be a promising hydrogen storage material under realistic conditions.