Phase equilibria for the pseudo-ternary system(NaCl+Na2SO4+H2O)of coal gasification wastewater at T=(268.15 to 373.15)K

The pseudo-ternary system(Na Cl + Na_2SO_4+ H_2O) of coal gasification wastewater was studied at T =(268.15 to 373.15) K. The solubility and density of the equilibrium liquid phase were determined by the isothermal solution saturation method. The equilibrium solids were also investigated by the Schreinemaker's method of wet residues and X-ray powder diffraction(XRD). According to the experimental data, the phase diagrams were determined. It was found that there was no significant solubility difference on the Na Cl-rich side between the ternary system(Na Cl + Na_2SO_4+ H_2O) in coal gasification wastewater and in pure water. However, the solubility on the Na_2SO_4-rich side of coal gasification wastewater was apparently higher than that of pure water. The increase in the solubility of Na_2SO_4 was most likely caused by the effects of other impurities apart from Na Cl and Na_2SO_4 in coal gasification wastewater. The measured data and phase equilibrium diagrams can provide fundamental basis for salt recovery in coal gasification wastewater.

Oxygen Vacancy-Enriched FeOx Nanoparticle Electrocatalyst for the Oxygen Reduction Reaction

FeOx electrocatalysts for the oxygen reduction reaction were prepared via one-step synthesis using electron impact with cold plasma as the electron source.Given the low operation temperature,FeOx by plasma technology showed a smaller particle size than that prepared via conventional calcination.Notably,electron impact produced more oxygen vacancies and a larger surface area on FeOx,which increased active sites and electronic conductivity,than plasma.Electrochemical investigations indicated that FeOx prepared by plasma exhibited remarkable oxygen reduction reaction activity toward the four-electron electrochemical reduction of oxygen.The results demonstrated that this facile fabrication method is a promising route for developing cost-eff ective and high-performance catalysts to be used in electrochemical applications.

Measurement and correlation of the solid-liquid equilibrium of 2-（tert-butyl）-5-methylphenol and 2-（tert-butyl）-4- methylphenol binary system

In this work, the enthalpy of fusion and melting points of 2-（tert-butyl）-5-methylphenol （2B5MP） and 2-（tert-butyl）-4-methylphenol （2B4MP） were measured by differential scanning calorimetry （DSC）. The binary solid-liquid equilibrium （SLE） of both compounds were predicted by integrated computer aided system （ICAS） and measured by DSC. The corresponding eutectic molar composition is 0.6998 and the eutectic temperature is 281.96 K. The quasi-static heat capacities of 2B5MP and 2B4MP were evaluated by stochastic temperature modulation DSC technique （TOPEM）. The SLE experimental data were correlated using the Margules, Wilson, and non-random two liquid （NRTL） equations and a good agreement between measurement and calculation could be obtained.

Tuning nitrogen defects and doping sulfur in carbon nitride for enhanced visible light photocatalytic activity

Defect construction and heteroatom doping are effective strategies for improving photocatalytic activity of carbon nitride(g-C_(3)N_(4)).In this work,N defects were successfully prepared via cold plasma.High-energy electrons generated by plasma can produce N defects and embed sulfur atoms into g-C_(3)N_(4).The N defects obviously promoted photocatalytic degradation performance that was 7.5 times higher than that of pure g-C_(3)N_(4).The concentration of N defects can be tuned by different power and time of plasma.With the increase in N defects,the photocatalytic activity showed a volcanic trend.The g-C_(3)N_(4)with moderate concentration of N defects exhibited the highest photocatalytic activity.S-doped g-C_(3)N_(4)exhibited 11.25 times higher photocatalytic activity than pure g-C_(3)N_(4).It provided extra active sites for photocatalytic reaction and improved stability of N defects.The N vacancy-enriched and S-doped g-C_(3)N_(4)are beneficial for widening absorption edge and improving the separation efficiency of electron and holes.