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Strontium Titanate has a typical perovskite structure with advantages of low cost and photochemical stability. However, the wide bandgap and rapid recombination of electrons and holes limited its application in photocatalysis. In this work, a SrTiO3 material with surface oxygen vacancies was synthesized via carbon reduction under a high temperature. It was successfully applied for photocatalytic overall water splitting to produce clean hydrogen energy under visible light irradiation without any sacrificial reagent for the first time. The photocatalytic overall water splitting ability of the as-prepared SrTiO3-C950 is attributed to the surface oxygen vacancies that can make suitable energy levels for visible light response, improving the separation and transfer efficiency of photogenerated carriers.

Biomass pyrolysis oil is a renewable resource and some of compounds (such as ketones, phenols and furans) in biomass pyrolysis oil are very useful compounds that can be used as raw materials for production of fine chemicals. Vapor-liquid equilibrium (VLE) data are critical and fundamental for designing distillation separation process. The VLE experiment and calculation of ketone-related binary systems (2-butanone + cyclopentanone, 2,3-butanedione + cyclopentanone) at atmospheric pressure are studied in this work. Binary interaction parameters of activity coefficient models (NRTL, Wilson and UNIQUAC) are obtained by correlating VLE experimental data. The new group CH2COCH2 is defined and the new group interaction parameters are presented and used to predict VLE data by UNIFAC-DMD model. The distillation separation process of ketones is designed and simulated based on VLE results. This work will provide theoretical basis and technical guidance for industrial separation process of biomass pyrolysis oil.

Carbon dioxide enhanced oil recovery (CO 2 EOR) process is widely used in petroleum industry in recent years. But it has some shortcomings, such as early gas breakthrough, fingering, asphaltene precipitations, because of the low viscosity and density of CO 2 . These problems can be resolved by adding some common solvents as chemical modifiers in CO 2 flooding. In this work, ethanol was chosen as the chemical modifier. The effects of ethanol on the equilibrium interfacial tension (IFT) of paraffin + CO 2 systems were investigated with different ethanol contents, temperature range 60–100 °C and pressure range 5.06–14.60 MPa, respectively. New correlation for predicting the IFTs of paraffin + modified CO 2 systems were proposed based on 150 experimental IFT values. The square of correlation coefficient ( R 2 ), root mean square error ( RMSE ) and average absolute relative deviations ( AARD ) were 0.9948, 0.15 and 2.49%, respectively. The paraffin IFTs for modified CO 2 and pure CO 2 flooding were compared by the IFT average absolute decrease ratio ( AADR ).

Interfacial tension (IFT) is crucial for characterizing the phase and interphase behavior in the enhanced oil recovery (EOR) process. CO2 and N2 are commonly used as injection gases in the EOR process. In this work, an experimental apparatus using the pendent drop method was adopted to measure IFTs for the EOR process with different injection gases, temperatures (40.0–120.0 °C) and pressures (0.22–17.32 MPa). The relative Gibbs adsorption isotherm (Γij) of a species i on species j were calculated by the experimental IFTs. Theoretically, new correlations were proposed to predict paraffin IFTs for pure CO2 and mixture gas (CO2 + N2) injection. A total of 561 and 268 experimental IFTs were used to derive the correlations for pure CO2 and mixture gas injection, respectively. The square of correlation coefficient (R2), root mean square error (RMSE) and average absolute relative deviations (AARD) for pure CO2 were 0.9884, 0.58 and 5.45%, respectively. For the mixture gas injection, the R2, RMSE and AARD of the correlation were 0.9851, 0.57 and 4.47%, respectively.

Three sulfur‐containing pyran‐annulated perylene diimides (PDIs) were synthesized from commercially available PDIs through a nucleophilic substitution/cyclization reaction sequence. The as‐synthesized compounds were fully characterized by 1H and 13C NMR, and FT‐IR spectroscopy, as well as HRMS and TGA. The as‐prepared PDI derivatives exhibited significantly narrow HOMO–LUMO band gaps and high photochemical and thermal stability. Moreover, these materials exhibited quite different absorptions and emissions in dichloromethane, which were in agreement with the DFT‐calculated results.

Miscible gas flooding is one of the most effective methods for enhanced oil recovery (EOR). A key and important parameter in designing an efficient miscible gas flooding is the minimum miscibility pressure (MMP). It is very essential to determine and predict gas–oil MMP for EOR technology. In this work, both the experiment and correlation approaches for obtaining gas–oil MMP were studied. Experimentally, a set of apparatus with the vanishing interfacial tension (VIT) technique was set up and utilized to determine the gas–oil MMP for three different kinds of injection gas. Theoretically, a new model was proposed to predict the gas–oil MMP. A total of 156 experimental MMP data were achieved from this work and literature was used to train and test the model. The average absolute relative deviations (AARD%) of the training set for pure CO2, CO2 mole fraction less than 0.5 (xCO2 0.5) in the injection gas are 5.85%, 4.06% and 6.49%, respectively. The AARD% of the testing set are 2.08%, 2.97% and 5.26%, respectively. The model is applied to calculate the gas–oil MMP in different CO2 purity flooding with CO2 mole fraction in the injection gas from 0.0352 to 1.

In this work a new topological index (TI) was proposed based on atom characteristics (e.g., atom radius, atom electronegativity, etc.) and atom positions in the hydrogen-suppressed molecule structure. Using the TIs, a multiple linear regression (MLR) model was developed for predicting the decomposition temperature (Td) of 158 ionic liquids (ILs), which are based on imidazolium, pyridinium, pyrrolidinium, ammonium, phosphonium, sulfonium, and guanidinium. Because ILs are a class of molten salts which are composed entirely of cations and anions, in general, the descriptors for ILs are calculated from cations and anions separately, and the interaction between them is neglected. In this study, except for the two sets of TIs generated from cations and anions, a third TI was proposed to depict the interaction of anions and cations. The regression coefficient (R2) and the overall average absolute deviation (AAD) are 0.893 and 3.07 %, respectively.

The general topological indexes (TIs) proposed in our previous work were applied to predict the surface tensions of ionic liquids (ILs) by Quantitative Structure Property Relationship (QSPR) method. ILs are a class of molten salts which are composed entirely of cations and anions, therefore the descriptors for ILs are generally calculated from cations and anions separately and the interaction between them is always neglected. In this study, besides the two sets of TIs generated from cation and anion, a third TI was used to depict the interaction of anion and cation. Differing from the previous estimation methods for surface tensions of ILs, the temperature dependence is also correlated by structure parameters. 930 surface tension data points for 115 ILs are applied to develop QSPR model. The correlation coefficient (R2) and the overall average absolute deviation (AAD) are 0.9516 and 3.43%, respectively.