Latest ArticlesPressure-related sensing materials in mechanochromic luminescent materials have received wide attention. However, at present, most piezochromic luminescence (PCL) materials have problems such as aggregation-caused quenching (ACQ) effect due to the presence of powder form, complicated preparation methods and fluorescence quenching effect under high pressure. To solve these problems, we employ three components containing carbon dots (CDs), layered double hydroxides (LDHs) and polyvinyl alcohol (PVA) to construct the CDs-LDHs/PVA film. The LDHs can provide a rigid environment for CDs and improve the luminescent efficiency of CDs. The film shows high sensitivity, stability and reversibility. Moreover, the compressed film can recover to its original state by heating. Therefore, the PCL film with dual emission (fluorescence and phosphorescence) characteristic is constructed, which boosts the sensitivity of pressure-sensing.
Electrochemical oxidation of water to produce highly reactive hydroxyl radicals (OH) is the dominant factor that accounts for the organic compounds removal efficiency in water treatment. As an emerging carbon-based material, the investigation of electrocatalytic of water to produce OH on Graphdiyne (GDY) anode is firstly evaluated by using first-principles calculations. The theoretical calculation results demonstrated that the GDY anode owns a large oxygen evolution reaction (OER) overpotential (ηOER=1.95 V) and a weak sorptive ability towards oxygen evolution intermediates (HO*, not OH). The high Gibbs energy change of HO* (3.18 eV) on GDY anode makes the selective production of OH (ΔG=2.4 eV) thermodynamically favorable. The investigation comprises the understanding of the relationship between OER to electrochemical advanced oxidation process (EAOP), and give a proof-of-concept of finding the novel and robust environmental EAOP anode at quantum chemistry level.
Diamide compounds such as chlorantraniliprole, a famous anthranilic diamide insecticide targeting the insect ryanodine receptor (RyR), have received continuous attention in pesticide research during the past 15 years owing to their excellent insecticidal potentials. With the aim of discovering new heterocyclic pesticides used for crop protection, based on the structural information of compound M from the reported pharmacophore-based virtual screening for RyR insecticides and diamide compound, a series of new heterocyclic mono-, di-, and tri-amide derivatives containing piperazine moiety have been synthesized in this paper. The new compounds were identified and confirmed by melting point, 1H NMR, 13C NMR and HRMS. Compound M was firstly validated for insecticidal activities, and the new synthesized compounds were all made comprehensive insecticidal evaluations against diamondback moth and oriental armyworm. The bioassay results showed that some of the compounds exhibit favorable insecticidal potentials, particularly some novel piperazine-containing heterocyclic mono-/di-/tri-amide derivatives such as 8g, 14a, 15a, 15g, 15i, 15j, 15k, 15l, and 15m could be used as new insecticidal leading structures for further study (e.g., towards diamondback moth, 15i-15m LC50: 0.0022−0.0081 mg/L). The structure-activity relationships of the compounds discussed in detail provide useful guidance for further design and development of new insecticides.
Silver-catalyzed decarboxylative C-H alkylation of cyclic aldimines with abundant aliphatic carboxylic acids has been realized under mild reaction conditions generating the corresponding products in moderate to good yields (32%-91%). In addition, a gram-scale reaction, late-stage modification of drug, synthetic transformation of the product, and further application of the catalytic strategy were also performed. Preliminary studies indicate that the reaction undergoes a radical process.
In recent years, lanthanum-based nanomaterials (La-NMs) are selected as an efficient nano-adsorbent for phosphate removal because La3+ has a strong affinity with oxygen-donor atoms from phosphate. Additionally, there are a broad interest and literature base for the effect of different synthesis optimization and environmental parameters on the adsorption performance of La-NMs. A considerable amount of research has also investigated the regeneration and application of La-NMs to real wastewater in a laboratory scale. Based on the literature survey, it was found that La-NMs are often produced via co-precipitation and hydrothermal methods. Moreover, phosphate's adsorption process and behavior onto La-NMs are described well with the pseudo-second-order model and Langmuir model. The interaction mechanism between phosphate and La-NMs are dominated by ligand exchange, surface complexation and electrostatic attraction. Furthermore, phosphate could easily desorb from La-NMs due to the weak H-bonding interaction between phosphate and the H-bond acceptor groups on the surface of La-NMs. Despite the wealth of literature available in this area, there is a lack of systematic review to evaluate the gaps in the use of La-NMs to eliminate phosphate in water. In this review, we mainly summarize and discuss the role and the effect of the synthesis techniques on the physicochemical properties and the adsorption behavior of La-NMs. The possible adsorption mechanism, regeneration efficiency, and the application of La-NMs to the real environmental samples are also presented and highlighted.
Electrochemical overall water splitting is attracting a broad focus as a promising strategy for converting the electrical output of renewable resources into chemical fuels, specifically oxygen and hydrogen. However, the urgent challenge in water electrolysis is to search for low-cost, high-efficiency catalysts based on earth-abundant elements as an alternative to the high-cost but effective noble metal-based catalysts. The transition metal-based catalysts are more appealing than the noble metal catalysts because of its low cost, high performance and long stability. Some recent advances for the development in overall water splitting are reviewed in terms of transition metal-based oxides, carbides, phosphides, sulfides, and hybrids of their mixtures as hybrid bifunctional electrocatalysts. Concentrating on different catalytic mechanisms, recent advances in their structural design, controllable synthesis, mechanistic insight, and performance-enhancing strategies are proposed. The challenges and prospects for the future development of transition metal-based bifunctional electrocatalysts are also addressed.
Carbon dots (CDs) have opened up a new field of carbon nanomaterials and successively attracted increasing attention since their discovery in 2004. Owing to their ultrasmall size, tunable surface functional groups, excellent dispersibility, attractive stability, low toxicity, environmental friendliness, facile synthesis and low-cost precursors, CDs have been developed as green and promising friction-reducing and anti-wear materials in lubrication science, applied to energy conservation and extension of mechanical service life in recent years. However, there are few reviews focusing on the application of CDs in the important field of lubrication. In this review, we comprehensively summarize the development of CDs in lubrication for the first time. Firstly, three strategies for structural engineering design of CDs to improve their tribological characteristics are fully analyzed, in terms of size and shape control, surface modification and heteroatom doping. Secondly, the advance in lubrication application of CDs, including CDs as additives for lubricants, greases, gel and magnetorheological fluids as well as CDs as lubricating coatings, is systematically highlighted. Thirdly, the lubricating mechanisms of CDs as additives are introduced in detail. Furthermore, the remaining major challenges and opportunities for CDs in lubrication field are discussed and outlined.
Substituent effect of metal porphyrin molecular catalysts plays a crucial role in determining the catalytic activity of oxygen electrocatalysis. Herein, substituent position effect of Co porphyrins on oxygen electrocatalysis, including the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER), was investigated. Two Co porphyrins, namely 2, 4, 6-OMe-CoP and 3, 4, 5-OMe-CoP, were selected as the research objects. The ORR and OER performance was evaluated by drop-coating molecular catalysts on carbon nanotubes (CNTs). The resulted 3, 4, 5-OMe-CoP/CNT exhibited high bifunctional electrocatalytic activities and better long-term stability for both ORR and OER than 2, 4, 6-OMe-CoP/CNT. Furthermore, when applied in the Zn-air battery, 3, 4, 5-OMe-CoP/CNT exhibited comparable performance to that with precious metal-based materials. The enhanced catalytic activity may be attributed to the improved charge transfer rate, mass transfer and hydrophilicity. This work provides an effective strategy to further enhance catalytic activity by introducing substituent position effect, which is of great importance for developing more efficient energy-related electrocatalysts.
Zero-dimensional carbon dots have emerged as important nanofillers for the separation membrane due to their small specific size and rich surface functional groups. This study proposed a strategy based on hydrophobic carbon dots (HCDs) to regulate water channels for an efficient forward osmosis (FO) membrane. Thin-film composite (TFC) membranes with superior FO performance are fabricated by introducing HCDs as the nanofiller in the polyacrylonitrile support layer. The introduction of HCDs promotes the formation of the support layer with coherent finger-like hierarchical channels and micro-convex structure and an integrated polyamide active layer. Compared to the original membrane, TFC-FO membrane with 10 wt% HCDs exhibits high water flux (15.47 L m−2h−1) and low reverse salt flux (2.9 g m−2h−1) using 1 mol/L NaCl as the draw solution. This improved FO performance is attributed to the lower structural parameters of HCDs-induced water channels and alleviated internal concentration polarization. Thus, this paper provides a feasible strategy to design the membrane structure and boost FO performance.
Metal-organic frameworks (MOFs) with porous crystal structures have attracted extensive attention in application of energy storage and conversion, owing to their regularity, porosity, large specific surface area, etc. In this work, Co-MOF-74 microflower has been successfully prepared via a controllable solvent regulation strategy. Through modulating the polarity of the solvent, crystals grow in certain preferred orientation and Co-MOF-74 with various morphologies were obtained. Thereinto, the energy storage performance of Co-MOF-74 microflower was measured in both three-electrode system and asymmetric supercapacitor device (specific capacitance of 164.2 F/g at 0.5 A/g in the three-electrode system and 62.5 F/g at 1 A/g in the asymmetric supercapacitor device). This can be attributed to the preferred crystal orientation resulting in a regular and uniform microflower, which is of great significance to electronic interfacial exchange and ion transfer during electrochemical reactions.