scispace - formally typeset
Search or ask a question
Author

Cheng-An Li

Bio: Cheng-An Li is an academic researcher from Nanjing Tech University. The author has contributed to research in topics: Computer science & Catalysis. The author has an hindex of 3, co-authored 5 publications receiving 31 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: In this article, a facile in situ surface assembly strategy was designed to construct polymeric [Cu 2 I 2 L 2 ] n on the surface of TiO 2 nanoparticles.
Abstract: 1D loop chain copper(I) cluster, [Cu 2 I 2 L 2 ] n , can be obtained based upon 9-(3-phenylselanyl-2-phenylselanylmethylpropyl)anthracene ( L ) and CuI. A facile in situ surface assembly strategy was designed to construct polymeric [Cu 2 I 2 L 2 ] n on the surface of TiO 2 nanoparticles. The visible-light photocatalytic property of core-shell TiO 2 -[Cu 2 I 2 L 2 ] n was confirmed by effective reduction of aqueous chromium(VI), showing a clear correlation to optical absorption ( E g = 2.8 eV). The key points of this strategy include high reactivity between copper(I) and soft selenium atom, efficient charge-transfer through polymeric cluster shell, and visible-light photoactivity of copper(I) halogen clusters.

17 citations

Journal ArticleDOI
Cheng-An Li1, Wei Ji1, Jian Qu1, Su Jing1, Fei Gao2, Dunru Zhu1 
TL;DR: A catalytic procedure using poly(ethylene glycol) (PEG-400) as a greener alternative organic solvent has been developed and can achieve 99% targeted yield with a mild reaction temperature and short reaction time.
Abstract: The catalytic activities of eight copper(i) halide clusters assembled from copper(i) halide and ferrocenyltelluroethers, 1-8, were investigated in C-N formation under various conditions. A catalytic procedure using poly(ethylene glycol) (PEG-400) as a greener alternative organic solvent has been developed. The PEG-400/5 system can achieve 99% targeted yield with a mild reaction temperature and short reaction time. After the isolation of the products by extraction with diethyl ether, this PEG-400/cluster system could be easily recycled. Spectroscopic studies elucidate a stepwise mechanism: firstly, proton-coupled electron transfer (PCET) involving the transfer of an electron from Cu+ and a proton from imidazole results in the formation of a labile penta-coordinated Cu2+ and aryl radical; the following effective electron transfer from the ferrocene unit reduces Cu2+ and forms the target product; finally, the ferrocenium unit is reduced by the I- anion. The merits of this eco-friendly synthesis are the efficient utilization of reagents and easy recyclability.

10 citations

Journal ArticleDOI
TL;DR: In this paper, a series of ferrocenyltelluroether based cuprous halide clusters were investigated as effective single-molecule metallaphotocatalysts (SMP) in white light-driven C H arylation at room temperature and air.

7 citations

Journal ArticleDOI
TL;DR: This work proposes a versatile and real-time trajectory optimization method that can generate a high-quality feasible trajectory using a full vehicle model under arbitrary constraints, leveraging the differential property of car-like robots to simplify the trajectory planning problem.
Abstract: —As a core part of autonomous driving systems, motion planning has received extensive attention from academia and industry. However, there is no efficient trajectory planning solution capable of spatial-temporal joint optimization due to nonholonomic dynamics, particularly in the presence of unstruc- tured environments and dynamic obstacles. To bridge the gap, we propose a versatile and real-time trajectory optimization method that can generate a high-quality feasible trajectory using a full vehicle model under arbitrary constraints. By leveraging the differential flatness property of car-like robots, we use flat outputs to analytically formulate all feasibility constraints to simplify the trajectory planning problem. Moreover, obstacle avoidance is achieved with full dimensional polygons to generate less conservative trajectories with safety guarantees, especially in tightly constrained spaces. We present comprehensive bench- marks with cutting-edge methods, demonstrating the significance of the proposed method in terms of efficiency and trajectory quality. Real-world experiments verify the practicality of our algorithm. We will release our codes as open-source packages with the purpose for the reference of the research community. 1

5 citations

Patent
21 Sep 2016
TL;DR: In this paper, a cuprous selenide cluster supported visible-light-induced catalyst with a property of reducing Cr (VI) ions is presented, which performs catalysis only under irradiation of a visible light source; chemical conversion of pollutants is fast, and the period of water purification can be shortened; the selected compounds are stable, and secondary pollution caused by decomposition or difficulty in recycle can be avoided.
Abstract: The invention discloses a cuprous selenide cluster supported visible-light-induced catalyst with a property of reducing Cr (VI) ions. According to the principle of the catalyst, a selenide-containing aromatic nucleus ligand is designed, a cuprous cluster complex of the selenide-containing aromatic nucleus ligand is taken as a sensitizer, the selenide-containing aromatic nucleus ligand is supported to TiO2 through physical absorption step by step, and then the compounds are taken as the catalyst for characterizing optical properties; analysis validation is performed with a diphenylsemicarbazide color developing agent. The invention further discloses a preparation method of the catalyst. The catalyst performs catalysis only under irradiation of a visible light source; chemical conversion of pollutants is fast, and the period of water purification can be shortened; the selected compounds are stable, and secondary pollution caused by decomposition or difficulty in recycle can be avoided; a chemical material for wastewater treatment is abundant, low in cost, non-toxic and environment-friendly.

3 citations


Cited by
More filters
01 Apr 2010
TL;DR: Computational investigations of ligand-directed selectivities in Ullmann-type coupling reactions of methanol and methylamine with iodobenzene by beta-diketone- and 1,10-phenanthroline-ligated Cu(I) complexes are reported, finding N-arylation is predicted to be favored in these cases, in agreement with experimental results.
Abstract: Computational investigations of ligand-directed selectivities in Ullmann-type coupling reactions of methanol and methylamine with iodobenzene by β-diketone- and 1,10-phenanthroline-ligated CuI complexes are reported. Density functional theory calculations using several functionals were performed on both the nucleophile formation and aryl halide activation steps of these reactions. The origin of ligand-directed selectivities in N- versus O-arylation reactions as described in a previous publication (J. Am. Chem. Soc. 2007, 129, 3490−3491) were studied and explained. The selectivities observed experimentally are derived not from initial CuI(nucleophile) complex formation but from the subsequent steps involving aryl halide activation. The arylation may occur via single-electron transfer (SET) or iodine atom transfer (IAT), depending on the electron-donating abilities of the ligand and nucleophile. Mechanisms involving either oxidative addition/reductive elimination or σ-bond metathesis are disfavored. SET mec...

272 citations

Journal ArticleDOI
TL;DR: In this article, a review on the investigation and development of various support materials in TiO2 photocatalyst system with special emphasis on the photodecolorization of synthetic dyes is presented.
Abstract: This review focuses on the investigation and development of various support materials in TiO2 photocatalyst system with special emphasis on the photodecolorization of synthetic dyes. Efforts have been devoted to find suitable support material of TiO2 for improving its recovery efficiency and adsorption capability. The relationship between the structural characteristics and physicochemical reactivity properties of the supported TiO2 photocatalysis has been highlighted. The vicinity of photocatalysis and support system significantly accelerated the transfer step between adsorption and overall oxidative of decolorization process. Comparison of the photodecolorization with several synthetic dyes has been made and concluded that the photocatalytic activities have been influenced by the structural and surface properties of the photocatalyst.

72 citations

Journal ArticleDOI
TL;DR: In this paper, the degradation performance of BiOBr/Ti3C2 nanocomposite was evaluated by the degradation efficiency of rhodamine B (RhB), 2,4Dinitrophenol (2,4-DNP) and Cr(VI).
Abstract: Photocatalytic purification of wastewater is a very attractive method to remove pollutants. However, it has not been widely used in the industry due to limitations in photocatalytic performance and the complexity and diversity of contaminants. It is of great significance to simultaneous treatment of multiple pollutants. In this work, we designed and successfully synthesized a BiOBr/Ti3C2 nanocomposite by electrostatically driven self-assembly method. The degradation performance of BiOBr/Ti3C2 nanocomposite was evaluated by the degradation efficiency of rhodamine B (RhB), 2,4-Dinitrophenol (2,4-DNP) and Cr(VI). By coupling the Ti3C2 with BiOBr, the degradation activity of BiOBr was greatly improved. The degradation apparent rate constant of rhodamine B(RhB), 2,4-Dinitrophenol (2,4-DNP) and Cr(VI) with BiOBr/Ti3C2 were 1.2, 1.3, 6 times that of BiOBr, respectively. The photocatalytic performance of BiOBr/Ti3C2 toward RhB still maintained 85.6% after 5 cycles. The use of BiOBr/Ti3C2 deal with the multicomponent pollutants has also been achieved. The results showed that RhB and Cr(VI) can be completely removed with 80 min by BiOBr/Ti3C2. The enhanced catalytic performance mainly arises from the formation of Schottky junction at BiOBr-Ti3C2 interface, which greatly promoted the separation of carriers. This work provides a new insight into the design of Ti3C2 based Schottky photocatalysts.

64 citations

Journal ArticleDOI
TL;DR: In this paper, a sunlight-active photocatalyst capable of magnetically separating prepared by depositing various amounts of N-doped carbon quantum dots (N-CQDs) on the Fe3O4/C/TiO2 (FCT) nanocomposite was investigated in the decolorization of methylene blue (MB), under UV, visible and sunlight irradiation.

46 citations

Journal ArticleDOI
TL;DR: In this article, the photocatalytic rate constant (0.0449min−1) of C/TiO2 nanocomposites with 3 ¼wt% CQDs is 8.6 times higher than that of pure TiO2 nanoparticles.
Abstract: Carbon quantum dots (CQDs) having sizes of 5–10 nm have been prepared facilely by a hydrothermal method and incorporated with TiO2 nanoparticles to produce CQDs-decorated TiO2 (C/TiO2) nanocomposites with various dosages of CQDs. Under visible-light irradiation, the photocatalytic activities of Cr(VI) reduction via C/TiO2 nanocomposites have been monitored and found to depend highly on the dosage of CQDs. In particular, the photocatalytic rate constant (0.0449 min−1) of C/TiO2 nanocomposites with 3 wt% CQDs is 8.6 times higher than that of pure TiO2 nanoparticles. When CQDs are excited by visible light, photo-generated electrons transfer from CQDs into the conduction band of TiO2 on the time scale of 1500 ps. Transferred electrons are subsequently captured by Cr(VI) ions, reducing Cr(VI) into Cr(III). Thus, π-conjugated CQDs act as sensitizers to provide visible-light response to the TiO2 nanoparticles of C/TiO2 dyade structures, leading to the highly efficient photocatalytic reduction of Cr(VI). Our as-prepared C/TiO2 nanocomposites are applicable in an inexpensive way to treat wastewater by utilizing solar energy without employing electron donors.

43 citations