Latest ArticlesThe present review not only devotes on the environmental consequences of plastic bag wastes and other industrial wastes observable in the landfills, in the oceans or elsewhere but also gives a new insight idea on conversion of them into worth material, carbon, for the best electrochemical supercapacitor. Transformation of plastic wastes into high-value materials is the incentive for plastic recycling, end-of-life handling case for plastic bag wastes in practice quite limited. The plastic recycling waste for reuse saves energy compared with manufacturing virgin materials. Herein, we identified several synthetic methods to convert plastic waste and other industrial wastes into carbon material for supercapacitor. Different kinds of carbon materials, including nanofiber, nanotube, graphene, mesoporous carbon, etc., have been derived from plastic waste, and thus give a superior potential for transforming trash into a "gold capacitor". Finally, conclusions and future trends of high-voltage supercapacitors were made as well as the easy and mass production of high-performance electrode materials for supercapacitors. Our work offers a promising sustainable approach to handle plastic bags, waste, and other industrial wastes and provides a new avenue in supercapacitor applications and other areas.
Methane (CH4) is not only used as a fuel but also as a promising clean energy source for hydrogen generation. The steam reforming of CH4 (SRM) using photocatalysts can realize the production of syngas (CO + H2) with low energy consumption. In this work, Ag0/Ag+-loaded SrTiO3 nanocomposites were successfully prepared through a photodeposition method. When the loading amount of Ag is 0.5 mol%, the atom ratio of Ag+ to Ag0 was found to be 51:49. In this case, a synergistic effect of Ag0 and Ag+ was observed, in which Ag0 was proposed to improve the adsorption of H2O to produce hydroxyl radicals and enhance the utilization of light energy as well as the separation of charge carriers. Meanwhile, Ag0 was regarded as the reduction reaction site with the function of an electron trapping agent. In addition, Ag+ adsorbed the CH4 molecules and acted as the oxidation reaction sites in the process of photocatalytic SRM to further promote electron-hole separation. As a result, 0.5 mol% Ag-SrTiO3 exhibited enhancement of photocatalytic activity for SRM with the highest CO production rate of 4.3 μmol g-1 h-1, which is ca. 5 times higher than that of pure SrTiO3. This work provides a facile route to fabricate nanocomposite with cocatalyst featuring different functions in promoting photocatalytic activity for SRM.
Although platinum-based materials are regarded as the state-of-the-art electro-catalysts for hydrogen evolution reaction (HER), high cost and quantity scarcity hamper their scale-up utilization in industrial deployment. Herein, a one-step strategy was developed to synthesize multi-walled carbon nanotubes and reduced graphene oxide supported Pt nanoparticle hydrogel (PtNP/rGO-MWCNT), in which only ascorbic acid was used as the reductant for one-pot reduction of both GO and chloroplatinic acid. The hydrogel can be directly used as a flexible binder-free catalytic electrode to achieve high performance of HER. Compared to conventional strategies, the current strategy not only significantly reduces the Pt loading to 3.48 wt%, simplifies the synthesis process, but also eliminates the use of any polymer binders, thus decreasing the series resistance and improving catalytic activity. An overpotential of only 11 mV was achieved on as-prepared PtNP/rGO-MWCNT to drive a geometrical current density of 10 mA/cm2 in 0.5 mol/L H2SO4, with its catalytic activity being kept over 15 h. In acidic medium, the HER activity of the PtNP/rGO-MWCNT catalyst exceeds most of the reported Pt-based electro-catalysts and is 3-fold higher than that obtained on commercial Pt/C electrode.
An ambient pressure-induced calcination process was proposed to prepare g-C3N4 with different structures. The porcelain boat with designed porosity is used to control the ambient pressure to change the diffusion behavior of the reaction molecules, thereby controlling the layer structure and rich pyridinic N content of g-C3N4, thus renders superior lithium storage performance.
Recently, ZnO-based gas sensors have been successfully fabricated and widely studied for their excellent sensitivity and selectivity, especially in CO detection. However, detailed explorations of their mechanisms are rather limited. Herein, aiming at clarifying the sensing mechanism, we carried out density functional theory (DFT) calculations to track down the CO adsorption and oxidation on the ZnO (1010) and (1120) surfaces. The calculated results show that the lattice O of ZnO(1010) is more reactive than that of ZnO(1120) for CO oxidation. From the calculated energetics and structures, the main reaction product on both surfaces can be determined to be CO2 rather than carbonate. Moreover, the surface conductivity changes during the adsorption and reaction processes of CO were also studied. For both ZnO (1010) and (1120), the conductivity would increase upon CO adsorption and decrease following CO oxidation, in consistence with the reported experimental results. This work can help understand the origins of ZnO-based sensors' performances and the development of novel gas sensors with higher sensitivity and selectivity.
Herein, we first report one-step synthesis of uniform Mo2C microflowers (MCMFs) from low-cost precursors via industrialized solid-state strategy. With fine optimization in precursor ratio and pyrolysis temperatures, the as-fabricated MCMFs are assembled well with interconnected single-crystalline nanosheet subunits. More encouragingly, the resultant MCMFs are further highlighted as a competitive anode with robust and long-duration lithium-storage behaviors towards high-performance Li-ion batteries
The compound[(CH3)2CH-C3H17N] [CoBr4] (1) based on quinuclidine derivatives was achieved by the solution synthetic method and characterized by elemental analysis, infrared spectroscopy, single-crystal X-ray structural analysis and dielectric measurement, respectively. Variable-temperature single-crystal X-ray diffraction suggested that the compound underwent the phase transition from the space group C2/c to Cc. The polarization curve was measured using the Sawyer-Tower circuit. The structural phase transitions of 1 was ascribed to the distortion of a[(CH3)2CH-C3H17N]2+ cation from this inorganic-organic hybrid material[(CH3)2CH-C3H17N] [CoBr4]. The strong change in dielectric anomalies makes compound 1 a suitable candidate for promising switchable dielectric materials. This work represents a feasible strategy thought for the targeted harvesting of low temperature ferroelectrics.
H2S can cause multiple diseases and poses a great threat to human health. However, the precise detection of extremely toxic H2S at room temperature is still a great challenge. Here, a facile solvent evaporation induced aggregating assembly (EIAA) method has been applied for the production of ordered mesoporous carbon (OMCs) in an acidic THF/H2O solution with high-molecular-weight poly(ethylene oxide)-b-polystyrene (PEO-b-PS) copolymers as the structure-directing agent, formaldehyde and resorcinol as carbon precursors. Along with the continuous evaporation of THF from the mixed solution, cylindrical micelles are formed in the solution and further assemble into highly ordered mesostructure. The obtained OMCs possesses a two-dimensional (2D) hexagonal mesostructure with uniform and large pore diameter (~19.2 nm), high surface area (599 m2/g), and large pore volume (0.92 cm3/g). When being used as the resonant cantilever gas sensor for room-temperature H2S detection, the OMCs has delivered not only a superior gas sensing performance with ultrafast response (14 s) and recovery (21 s) even at low concentration (2 ppm) but also an excellent selectivity toward H2S among various common interfering gases. Moreover, the limit of detection is better than 0.2 ppm, indicating its potential application in environmental monitoring and health protection.
Metalloenzymes which employ metal species and organic ligands as central active sites play significant roles in various biological activities. Development of artificial metalloenzymes can help to understand the related physiological mechanism and promote the applications of metalloenzymes in biosynthesis, energy conversion and biosensing. In this work, inspired by the active sites of ferriporphyrin-based metalloenzymes, Fe-MOFs by using ferric as the metal center and a porphyrin analog as the organic ligand were developed as an artificial metalloenzyme. The Fe-MOFs exhibit high peroxidase-like catalytic activity with excellent long-term stability. Moreover, highly sensitive biosensors were built to detect H2O2 and glucose based on the Fe-MOFs. Such MOFs-based artificial metalloenzyme offers an efficient strategy for the development of highly stable and efficient metalloenzymes, showing great potential in catalysis, energy transfer, biosensing and medical diagnosis.
Spirobisnaphthalenes comprise a relatively rare family of natural products that are normally isolated from fungi and occasionally from plants. Here we reported the discovery of seven new preussomerintype spirobisnaphthalenes, preussomerins YT1-YT7 (1-7), and seven known ones (8-14), from the endophytic fungus Edenia gomezpompae, enriching the structural diversity of this family of natural products. Their structures were established by 1D and 2D NMR spectroscopy, HRESIMS analysis and comparison with previously reported compounds, with the absolute configurations of compounds 1 and 2 being further confirmed by single-crystal X-ray diffraction using Cu Kα radiation. The antiinflammatory activities of all isolates were assessed by measuring the production of NO in LPS-induced RAW264.7 macrophage cells. Among them, compounds 8 and 13 exhibited potent inhibitory activities on the production of NO, with IC50 values of 2.61 and 1.32 μmol/L, respectively.