Jianliang Cao

Rechargeable lithium/iodine battery with superior high-rate capability by using iodine–carbon composite as cathode

A rechargeable lithium/iodine battery using commercial organic electrolyte, composed of iodine–conductive carbon black composite as cathode and metallic lithium as anode, is first proposed in this work. The fabricated lithium/iodine battery presents superior high-rate capability and good reversibility based on the contributions from both the capacitive characteristics of conductive carbon black, and the redox capacity of active iodine in the composite.

Homogeneous precipitation method preparation of modified red mud supported Ni mesoporous catalysts for ammonia decomposition

Red mud modified by an acid digestion and alkali reprecipitation approach was employed as support for the preparation of Ni/MRM catalysts using the homogeneous precipitation method. The textural and structural properties of the as-received red mud (RM), the modified red mud (MRM) and the as-prepared Ni/MRM catalysts were characterized by X-ray diffraction (XRD), energy dispersive X-ray fluorescence (EDXRF), thermogravimetry-differential scanning calorimetry analysis (TG-DSC), Fourier transform infrared spectra (FT-IR), transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectroscopy (EDX) and N2 sorption techniques. The analysis results revealed a mesoporous nanocatalyst system with high surface area and uniform pore-size distribution. The results of the catalytic activity measurements showed that these mesoporous nanostructured Ni/MRM catalysts were very active for ammonia decomposition. The catalyst with 15% Ni loading and calcined at 600 °C exhibited the highest catalytic activity. Due to its unique properties and the feature of resource utilization of industrial solid waste, MRM holds great promise for developing catalysts and catalyst supports for applications in various catalytic reactions including catalytic ammonia decomposition.

Synthesis of transition metal oxide nanoparticles with ultrahigh oxygen adsorption capacity and efficient catalytic oxidation performance

Transition metal oxide nanoparticles, such as CuO and NiO, with ultrahigh oxygen adsorption capacity were synthesized via a novel occlusional coprecipitation method, and exhibit very high activity in low-temperature CO catalytic oxidation.

Preparation of TiO 2 /activated carbon composites for photocatalytic degradation of RhB under UV light irradiation

Photocatalysts comprising nanosized TiO2 particles on activated carbon (AC) were prepared by a sol-gel method. The TiO2/AC composites were characterized by X-ray diffraction (XRD), thermogravimetric (TG) analysis, nitrogen adsorption, scanning electron microscope (SEM), transmission electron microscope (TEM), and energy dispersive X-ray (EDX). Their photocatalytic activities were studied through the degradation of Rhodamine B (RhB) in photocatalytic reactor at room temperature under ultraviolet (UV) light irradiation and the effect of loading cycles of TiO2 on the structural properties and photocatalytic activity of TiO2/AC composites was also investigated. The results indicate that the anatase TiO2 particles with a crystal size of 10-20 nm can be deposited homogeneously on the AC surface under calcination at 500°C. The loading cycle plays an important role in controlling the loading amount of TiO2 and morphological structure and photocatalytic activity of TiO2/AC composites. The porosity parameters of these composite photocatalysts such as specific surface area and total pore volume decrease whereas the loading amount of TiO2 increases. The TiO2/AC composite synthesized at 2 loading cycles exhibits a high photocatalytic activity in terms of the loading amount of TiO2 and as high as 93.2% removal rate for RhB from the 400 mL solution at initial concentration of 2 × 10-5 mol/L under UV light irradiation.

Synthesis of porous hematite nanorods loaded with CuO nanocrystals as catalysts for CO oxidation

Abstract Porous hematite (a-Fe 2 O 3 ) nanorods with the diameter of 20–10 nm and the length of 80–300 nm were synthesized by a simple surfactant-assisted method in the presence of cetyltrimethylammonium bromide (CTAB). The α-Fe 2 O 3 nanorods possess a mesostructure with a pore size distribution in the range of 5–12 nm and high surface area, exhibiting high catalytic activity for CO oxidation. CuO nanocrystals were loaded on the surface of porous α-Fe 2 O 3 nanorods by a deposition-precipitation method, and the catalysts exhibited superior activity for catalytic oxidation of CO, as compared with commercial a-Fe 2 O 3 powders supported CuO catalyst. The enhanced catalytic activity was attributed to the strong interaction between the CuO nanocrystals and the support of porous α-Fe 2 O 3 nanorods.

Methane explosion suppression characteristics based on the NaHCO3/red-mud composite powders with core-shell structure

The NaHCO3/red-mud (RM) composite powders were successfully prepared by the solvent-anti-solvent method for methane explosion suppression. The RM was used as a carrier, and the NaHCO3 was used as a loaded inhibitor. The NaHCO3/RM composite powders showed a special core-shell structure and excellent endothermic performance. The suppression properties of NaHCO3/RM composite for 9.5% CH4 explosion were tested in a 20L spherical explosion vessel and a 5L Perspex duct. The results showed that the NaHCO3/RM composite powders displayed a much better suppression property than the pure RM or NaHCO3 powders. The loading amount of NaHCO3 has an intensive influence on the inhibition property of NaHCO3/RM composite powders. The best loaded content of NaHCO3 is 35%. It exhibited significant inhibitory effect that the explosion max-pressure declined 44.9%, the max-pressure rise rate declined 96.3% and the pressure peak time delayed 366.7%, respectively.

Carbon quantum dots/nickel oxide (CQDs/NiO) nanorods with high capacitance for supercapacitors

Novel one-dimensional composites of carbon quantum dots (CQDs) coated NiO nanorods have been prepared via a facile complexation method followed by a thermal treatment process with no addition of organic solvent or surfactant. The carbon quantum dots/NiO (CQDs/NiO) nanorods are very uniform in size with an average length of about 800 nm and diameter of 30 nm. The CQDs/NiO hybrid nanorods deliver a high specific capacitance (1858 F g−1 at 1 A g−1), exceptional rate capability (84.6%, 75.7%, 65.3%, 56.1% and 51.5% capacity retention rate at 2, 3, 5, 7 and 10 A g−1, respectively) and excellent cycling stability (93% of the initial capacity retention over 1000 cycles at 2 A g−1) due to the coupled effect of faradaic pseudocapacitance from the NiO nanorods and the excellent electrical conductivity of the CQDs. These outstanding electrochemical performances demonstrate that the CQDs/NiO nanorods are efficient electrode materials and have a greatly promising application in the development of high-performance electrochemical energy storage devices.

Synthesis of g-C3N4 nanosheet modified SnO2 composites with improved performance for ethanol gas sensing

The composites of SnO2 have attracted much interest in the last few years due to their excellent sensing properties. A series of composites were prepared with two-dimensional (2D) g-C3N4 nanosheet modified SnO2 by a simple hydrothermal method in this work. The as-prepared composites were characterized by the techniques of powder X-ray diffraction (XRD), thermogravimetric analysis (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), N2 sorption and X-ray photoelectron spectroscopy (XPS). The gas sensing measurement results indicated that the sensor based on g-C3N4/SnO2 composite showed high sensitivity and excellent selectivity for detection of ethanol vapor. At 500 ppm of ethanol vapor, the response value (Ra/Rg) of 5 wt% 2D g-C3N4 modified SnO2 was 240 at 300 °C. Therefore, the g-C3N4/SnO2 composites have a great potential ethanol gas sensing application.

Calcination Method Synthesis of SnO2/g-C3N4 Composites for a High-Performance Ethanol Gas Sensing Application

The SnO2/g-C3N4 composites were synthesized via a facile calcination method by using SnCl4·5H2O and urea as the precursor. The structure and morphology of the as-synthesized composites were characterized by the techniques of X-ray diffraction (XRD), the field-emission scanning electron microscopy and transmission electron microscopy (SEM and TEM), energy dispersive spectrometry (EDS), thermal gravity and differential thermal analysis (TG-DTA), and N2-sorption. The analysis results indicated that the as-synthesized samples possess the two dimensional structure. Additionally, the SnO2 nanoparticles were highly dispersed on the surface of the g-C3N4nanosheets. The gas-sensing performance of the as-synthesized composites for different gases was tested. Moreover, the composite with 7 wt % g-C3N4 content (SnO2/g-C3N4-7) SnO2/g-C3N4-7 exhibits an admirable gas-sensing property to ethanol, which possesses a higher response and better selectivity than that of the pure SnO2-based sensor. The high surface area of the SnO2/g-C3N4 composite and the good electronic characteristics of the two dimensional graphitic carbon nitride are in favor of the elevated gas-sensing property.

Synthesis, characterization, and gas-sensing properties of monodispersed SnO2 nanocubes

Monodispersed single-crystalline SnO2 nanocubes with exposed a large percentage of high-energy surfaces have been synthesized by a simple solvothermal process at low temperature without any templates and catalysts. The as-prepared samples have been characterized by X-ray diffraction and transmission electron microscopy. Many outstanding characters of the final products have been shown, such as uniform particle size, high purity, and monodispersity. In property, superior gas-sensing properties such as high response, rapid response-recovery time, and good selectivity have also been shown to ethanol at an optimal working temperature of as low as 280 °C. It indicates that the as-prepared SnO2 nanocubes are promising for gas sensors.