Construction of high-performance electrode materials of NiCo2O4 nanoparticles encapsulated in ultrathin N-doped carbon nanosheets for supercapacitors.

Highly dispersed nitrogen doped carbon (N-C) is decomposed by 2-methylimidazole (C4H6N2) and is used as a composite material with nickel cobaltite (NiCo2O4). The N-C and NiCo2O4 composites are obtained by a one-step hydrothermal method and subsequent calcination. In addition, N-C is used to control the morphology and structure of NiCo2O4 to obtain excellent capacitor materials. The N-C/NiCo2O4 electrode shows an excellent specific capacitance of 157.97 mA h g-1 (1263.75 F g-1) at 1 A g-1. Herein, we successfully develop a N-C/NiCo2O4//AC asymmetric supercapacitor (ASC), which is prepared using N-C/NiCo2O4 as a cathode coupled with activated carbon (AC) as an anode at a voltage of 1.6 V. The prepared N-C/NiCo2O4//AC device shows an excellent volumetric energy density of 66.44 mW h kg-1. The promising performance of N-C/NiCo2O4//AC illustrated its potential for portable supercapacitor applications.

Fabricating acid-sensitive controlled PAA@Ag/AgCl/CN photocatalyst with reversible photocatalytic activity transformation.

Achieving the intelligent controllability of the photocatalyst to the surrounding environment is a very meaningful work. Here, the polyacrylic acid (PAA) modified Ag/AgCl-40/CN composite was constructed to achieve an intelligent response of pH value. PAA exhibits hydrophilic properties at high pH value, increasing the adsorption capacity to tetracycline (TC) molecules. The morphology of PAA from contracted state to diastolic state, releasing the Ag/AgCl-40/CN catalyst. In addition, PAA modified Ag/AgCl-40/CN can prevent the loss of AgCl. The g-C3N4 nanosheets (CN) as a carrier enhance the dispersibility of the AgCl particles. The LSPR effects of Ag nanoparticles produce more electrons acting on photocatalytic degradation. On the results of experiment, the degradation of TC by PAA@Ag/AgCl-40/CN shows an excellent degradation activity when the high pH value. Photoluminescence spectroscopy and photocurrent demonstrate that carrier separation efficiency of PAA@Ag/AgCl-40/CN is higher than CN and Ag/AgCl-40/CN. The detection of the main active substances •O2- and h+, revealing a reasonable mechanism for the PAA@Ag/AgCl-40/CN hybrid system. This work provides a procedure to obtain smart materials that can switch photocatalytic processes.

Fabricated rGO-modified Ag2S nanoparticles/g-C3N4 nanosheets photocatalyst for enhancing photocatalytic activity.

Photocatalytic technology provides a new strategy for the treatment of water pollution and energy crisis. Developing photocatalytic materials with high efficiency and stable visible light response has always been the direction of scientific researchers in the photocatalytic field. In this paper, we designed and prepared an efficient and stable rGO-modifited type-I Ag2S/g-C3N4 heterojunction photocatalyst (rGO/Ag2S/CN). The TEM (Transmission electron microscope) technology shows that the morphology of rGO/Ag2S/CN is a sandwich-like structure. UV-Vis DRS (UV-visible diffuse-reflectance spectrum) shows that the loading of Ag2S NPs and the modification of rGO effectively enhance the light response performance of nanocomposite materials in visible light. PL (Photoluminescence) and PEC (Photoelectrochemical) results prove that the photogenerated carriers transport and separation efficiency of rGO/Ag2S/CN have been improved. The photodegradation of RhB and the photoreduction of CO2 results confirmed that this ternary nanocomposite has great photocatalytic activity. The photodegradation efficiency of the RhB aqueous solution is about 98.5% after 30 min under the visible light irradiation. The photoreduction experiments showed that the yields of CO and CH4 are 178.05 µmol/g and 121.11 µmol/g, respectively after 8 h under the UV light irradiation. The results of cyclic photocatalytic experiments and the XRD pattern after those processes further revealed that the modification of rGO not only enhanced the photocatalytic performance of the nanocomposite photocatalyst, but also effectively improved the stability of Ag2S in the photocatalytic process. The possible photocatalytic reaction mechanisms were discussed in detail.

Structure-based 3D-QSAR studies on heteroarylpiperazine derivatives as 5-HT3 receptor antagonists.

Structure-based 3D-QSAR studies were performed on a series of novel heteroarylpiperazine derivatives as 5-HT(3) receptor antagonists with comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. The compounds were initially docked into the binding pocket of the homology model of 5-HT(3) receptor using GOLD program. The docked conformations with the highest score were then extracted and used to build the 3D-QSAR models, with cross-validated r(cv)(2) values 0.716 and 0.762 for CoMFA and CoMSIA, respectively. The CoMFA and CoMSIA contour plots were also fitted into the 3D structural model of the receptor to identify the key interactions between them, which might be helpful for designing new potent 5-HT(3) receptor antagonists.