SiO2 based superhydrophobic coating has been widely studied as a promising material to extend the service life of various materials. However, the simple preparation of a robust superhydrophobic coatings with room temperature curing capability at low cost is still a challenge in this field. In this work, the fluorinated SiO2 is made from inexpensive industrial water glass by a simple sol-gel method, and the coating is produced by a two-step brushing process and cured at room temperature. The stability of superhydrophobic coatings was verified by wear resistance, chemical stability, and high temperature resistance. Under the ideal preparation conditions obtained by hydrophobic characterizations, the contact angle can be as high as 158.9 degrees, the slide angle is only 3.2 degrees, and it has outstanding self-cleaning properties. The SiO2-EP superhydrophobic coatings notably possess exceptional wear resistance in both smooth glass and rough cement mortar surfaces. Especially on the glass, it can maintain to be superhydrophobic after being worn 50 cycles with 100 g load and 35 cycles with 200 g load on 600-mesh sandpaper. In addition, it maintains excellent superhydrophobic properties even under high temperatures of 300 degrees C and extreme acid and alkaline corrosive environments. This offers a broad range of

为了探究热处理对拜耳法赤泥胶凝特性的影响,采用对比强度法评价不同温度煅烧下赤泥的胶凝特性;并将赤泥与水泥熟料、石灰石粉、石膏按比例混合制备低碳胶凝材料,探究赤泥的热处理温度对低碳胶凝材料性能的影响,通过XRD分析赤泥的热处理温度对物相变化和胶凝材料的水化产物的影响.结果表明:随着热处理温度的升高,赤泥胶凝特性逐渐增强后减弱,在600℃时达到最佳;所制备的胶凝材料早期强度较高,但后期强度增长缓慢;胶凝特性好的赤泥在的水化反应中消耗更多的CH,同时会生成少量的单碳铝酸盐;利用热处理活化的赤泥制备的低碳胶凝材料每吨可减少约30%的CO2 排放和 20%的能耗.

Since the traditional g-C3N4 photocatalyst was severely affected by low charge transfer rates and light absorption capacity, which inevitably limited its application in environmental pollution treatment. Herein, mixing the 2,4,6-triaminopyrimidine (TAP) doped melamine and biomass porous carbon (BPC), the TAP-BPC/CN composite with desirable conductivity was synthesized by one step thermal condensation. That is, the carbon atom of TAP was used to partially replace the nitrogen atom of tri-s-triazine structure of g-C3N4, and decreased the interlayer distance of graphite lamellar structure, then improved the electrical conductivity of the materials and suppressed the recombination of photogenerated carriers. At the same time, the incorporation of BPC also contributed to increase the active sites of the material and enhance the separation efficiency of photogenerated carriers. Furthermore, the formation of p-n homojunction in TAP-BPC/CN built the construction of an internal electric field at the interface, which induced the band bending and improved charge separation and transfer effectively. As a result, the sample of TAP-BPC/CN exhibited an excellent adsorption and photocatalytic activities in the degradation of oxytetracycline (OTC). This research provides a new strategy for efficient photocatalysts with high absorption and photocatalysis in the antibiotic wastewater treatment.

A mesoporous g-C3N4 with guanidine hydrochloride as precursor was prepared by molten salt assisted hard template of silica (SiO2) aerogel for photocatalytic degradation of tetracycline (TC). The study shows that the successfully synthesized mesoporous g-C3N4 presented a coral-like rod shaped and heptazine ring structure. When the amount of SiO2 aerogel template was 1.4 g, the lower band gap (2.31 eV) of the sample (GM-1.4) with the lower interfacial resistance was displayed. The photocatalytic degradation rate of GM-1.4 for TC reached to 100% under visible illumination for 210 min, and the degradation efficiency of TC was enhanced with the synergistic effect of adsorption. Furthermore, the rich porous structure provided more active sites, boosted the separation and transfer of photoexcited charge carriers, and then enhanced the production of main active species ·O2− and h+, resulting in the efficient destruction of the intrinsic structure and functional groups of TC molecules.

Graphitic carbon nitride (g-C3N4) is widely used in photocatalytic adsorption and degradation of pollutants, but there are still some problems such as low adsorption performance and high electron-hole recombination efficiency. Herein, we propose a new molten salt assisted thermal polycondensation strategy to synthesize biomass porous carbon (BPC) loaded on g-C3N4 composites (designated as BPC/g-C3N4) with a hollow tubular structure, which had a high surface area and low electron-hole recombination rate. The study shows that the morphology of g-C3N4 changes dramatically from massive to hollow tubular by molten salt assisted thermal polycondensation, which provides a base for the loading of BPC, to construct a highly effective composite photocatalyst. BPC loaded on g-C3N4 could be used as the active site to enhance Oxytetracycline (OTC) removal efficiency by adsorption and with higher electron-hole separation efficiency. As a result, the BPC(5%)/g-C3N4 sample presented the highest photocatalytic degradation efficiency (84%) for OTC degradation under visible light irradiation. The adsorption capacity and photocatalytic reaction rate were 3.67 and 5.63 times higher than that of the g-C3N4, respectively. This work provided a new insight for the design of novel composite photocatalysts with high adsorption and photocatalytic performance for the removal of antibiotic pollutants from wastewater.

Since the traditional g-C3N4 photocatalyst was sever ely affected by low charge transfer rates and light absorption capacity, which inevitably limits its application in environmental pollution treatment. Herein, mixing the 2,4,6-triaminopyrimidine (TAP) doped melamine and biomass porous carbon (BPC), the TAP-BPC/CN composite with desirable conductivity and structure properties was synthesized by one step thermal condensation. The effects of the TAP doping amount and material characteristics on the adsorption and photocatalytic performance of the composite were investigated. The results show that the carbon atom of TAP partially replaced the nitrogen atom of tri-s-triazine structure of g-C3N4 , and decreased the interlayer distance of graphite lamellar structure, then improved the electrical conductivity of the materials and suppressed the recombination of photogenerated carriers. Meanwhile, the sample of 1TAP-BPC/CN exhibited the optimal removal efficiency for OTC, and the adsorption capacity and photocatalytic reaction rate was 4.39 times and 5.71 times than g-C3N4 , respectively. In addition, the mechanism of OTC photocatalytic on TAP-BPC/CN composite was further explored by active group capture experiments and photoelectrochemical characterization analyses, and the composite prepared by the BPC loaded on the TAP doping g-C3N4 was verified to enhance the OTC photocatalytic performance.

As a new nonmetallic photocatalysis material, it is of great attention to develop the carbon nitride (g-C3N4) with good structure and optical properties. Herein, a mesoporous g-C3N4 was prepared by molten salt-assisted silica (SiO2) aerogel template method, the properties of physicochemical and optical were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), specific surface area and pore analysis, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray energy spectrum (XPS), diffuse reflectance spectrum, fluorescence spectrum (PL) and zeta potential, respectively. Rhodamine B (RhB) was used for a series of adsorption and photocatalytic degradation experiments, and the reactive species and the degree of RhB degradation in the reaction process were tested by electron spin resonance (ESR) and UV–Vis absorption spectrum, respectively. The synergistic effect of adsorption and photocatalytic degradation was investigated. The results show that the mesoporous g-C3N4 was synthesized successfully, and presented a hollow tubular porous structure and good optical properties. With the highest specific surface area (164.65 m2·g−1) and narrower band gap (2.47 eV), the sample of M-CN-500 shown the highest degradation rate of RhB (90.9%) after 150 min illumination, and the adsorption capacity and zeta potential were both affected by pH variation. The kinetic model verified that the photocatalytic degradation rate of RhB by mesoporous g-C3N4 was enhanced with the synergistic effect of adsorption. It was also demonstrated that the O2− and h+ were the primary reactive species, and the RhB structure fracture was the main reason in the photocatalytic degradation. A mesoporous g-C3N4 was prepared by molten salt-assisted silica (SiO2) aerogel template method, and the synergistic effect of adsorption and photocatalytic degradation on this catalyst was investigated. Because of its special hollow tubular and porous structure, mesoporous g-C3N4 with high specific surface area can not only improve the adsorption performance, but also enhance the photocatalytic efficiency.