Papers by Author: Hong Bing Yu

Abstract: MgO-Al₂O₃-SiO₂ ceramics were recently explored as infrared radiance materials to provide an environmental friendly energy candidate for industrial heating and drying. Cu ferrite was selected to dope MgO-Al₂O₃-SiO₂ ceramics, forming a series of composite ceramics via solid-state reaction method to enhance the infrared radiation properties. The phase identification and morphologies of the samples were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. The infrared emissivity was examined by Fourier transform infrared (FTIR) spectrometer. The results showed that an improvement of infrared radiation properties can be achieved by doping Cu ferrite in MgO-Al₂O₃-SiO₂ ceramics. With increasing the dopant content from 0 wt % to 10.0 wt %, the crystallization behavior changed accordingly. A positive correlation was found between the infrared emissivity and the lattice strain. The highest infrared emissivity (0.91±0.01) was obtained after sintering at 1150 °C for 2 h with Cu ferrite content was 7.5 wt %, in which the maximum lattice strain (0.282 %) occurred. MgO-Al₂O₃-SiO₂ ceramics doped with Cu ferrite have potential for the application of infrared heating and drying fields.

Abstract: Volatile organic compounds (VOCs), especially toluene as the typical indoor air pollutants, are toxic and environmentally persistent whose removal is undoubtedly becoming increasingly urgent matter over these years. Titania is one of the most promising photocatalysts for the degradation of organic compounds, whereas the large band gap of titania and massive recombination of photogenerated charge carriers limit its overall photocatalytic effciency. These defects can be tackled by modifying the electronic band structure of titania including various strategies like metal deposition, non-metal atoms substitution, transition metal ions doping, and coupling with a narrow band gap semiconductor, etc. This review encompasses several advancements made in these aspects, and also the influence factors such as physical morphologies changing, humidity, as well as the presence of O2 etc, are involved. To be practically considering, TiO2 photocatalysts require being fixed on the bulky supports like silica, alumina, clays and activated carbons. Moreover, photocatalytic coatings deposited on external building materials, like roofing tiles and corrugated sheets, is becoming the attractive application potentials to remove toluene from air.

Abstract: Electrodeionization(EDI) is an electro-membrane process with high efficiency for deep desalinating, where water dissociation mechanism occurring on the surface of ion exchange membranes and resins typically exsits and acts. But when used to treat heavy metal-containing solutions such as effluents from the electronic industry, the EDI will suffer from metal-hydroxides precipitation which would destroy the separation process irreversible. With the primary aim to solve that problem, an electrodeionization process coupled with bipolar membrane (BMEDI) was developed together with a preacidification method. The effects of separating and concentrating heavy metal ions by the BMEDI were studied with NiSO₄ solution containing 24 mg×L^-1 Ni²⁺ ions. The results suggested that, the nickel-concentration in the dilute products were both below the analysis limit at constant current densities of 40 mA·cm^-2 and 10 mA·cm^-2, while a concentration factor of 31 was achieved at 40 mA·cm^-2. In addition, no Ni(OH)₂ precipitation was found in all the compartments throughout the experiments, which provide a guarantee of good stability for long-time operation.

Abstract: Using solid acid catalyst for the levulinic acid (LA) production from cellulose is one of the promising methods for utilization of biomass. An environmentally friendly solid acid catalyst, sulfated TiO2 was prepared by precipitation-impregnation method and used to catalyze the production of levulinic acid from cellulose. The concentration of sulphuric acid had a remarkable influence on the construction and catalytic activity of sulfated TiO2. The influence of reaction temperature and catalyst dosage on levulinic acid yield was also investigated with the aim to obtain the highest yield of LA. The optimum condition for the highest yield of levulinic acid (27.2%) was achieved at 240 °C, 0.7g of sulfated TiO2 and reaction time of 15 min. The recycling test indicated that the catalytic activity of the catalyst had a slight decrease after being used two times.