Solvothermal Synthesis and Pyrolysis Toward Heteroatom-Doped Carbon Microspheres for Zinc-Ion Hybrid Capacitors.

Heteroatom-doped porous carbon materials have investigated to promote the energy density of zinc-ion hybrid capacitors (ZICs). Yet, the quest for high-performance carbon materials or cathodes brings to light the question of which dopants facilitate fast energy storage kinetics and various types of pseudocapacitive reactions. Investigation of carbon materials with precise quantitative dopants as the key variable represents an effective appropriate approach to comprehending the intricate role of dopants in energy storage areas. Here, a straightforward solvothermal strategy is demonstrated for a variety of pristine and iron-incorporated polymer microspheres, used as precursors for durable spherical carbons intended for cathode applications in ZICs. The strategy effectively governs the incorporation of dopants within the carbon materials, whilewhile maintaining consistent morphology, microtexture, and pore structure across different carbon variations. The synergistic effect of various dopants enhance the pseudocapacitance and facilitate the ion storage process. In consequence, the optimal cathode delivers considerable capacity (178.8 mAh g-1 at 0.5 A g-1), good energy density (120.2 Wh kg-1 at 336 W kg-1), and excellent cycling stability (101.5% capacity retention at 35 000 cycles). The demonstration showcases a viable method for crafting carbon materials with precise dopants to accommodate the zinc anode, thus enabling high-capacity and high-energy ZICs.

Different morphologies on Cu-Ce/TiO2 catalysts for the selective catalytic reduction of NOx with NH3 and DRIFTS study on sol-gel nanoparticles.

The copper-cerium binary oxide catalysts supported by titanium dioxide with nanosphere core-shell structures, nanotube (TNT) core-shell structures, impregnation (imp) nanoparticles and sol-gel nanoparticles were prepared for NH3-SCR of NOx under medium-low temperature conditions. The effect of different morphologies on the Cu-Ce/TiO2 catalysts was comprehensively studied through physicochemical characterization. The results showed that the sol-gel nanoparticles exhibited 100% NOx reduction efficiency in the temperature range of 180-400 °C. Compared with the other catalysts, the sol-gel nanoparticle catalyst had the highest dispersion and lowest crystallinity, indicating that morphology played an important role in the NH3-SCR of the catalyst. The in situ DRIFTS study on the sol-gel nanoparticle catalyst shows that cerium could promote Cu2+ to produce abundant Lewis acid sites, which would significantly increase the adsorption reaction of ammonia on the catalyst surface, thereby promoting the occurrence of the Eley-Rideal (E-R) mechanism. With the Ce-Ti interaction on the atomic scale, the Ce-O-Ti structure enhanced the redox properties at a medium temperature. In addition, cerium oxide enhances the strong interaction between the catalyst matrix and CuO particles. Therefore, the reducibility of the CuO species was enhanced.

Monomer Emission Mechanism Research of Tetraphenylethene Derivative with Supramolecular Self-Assembly in Polymer Microspheres.

The monomer emission property of the tetraphenylethene (TPE) derivative is rarely reported, and its photoluminescence (PL) mechanism related to supramolecular self-assembly needs further in-depth research. Two long alkyl chain modified derivatives, the TPE derivative (TPE-C10) and pyrene derivative (Pyrene-C10), are designed and synthesized, which possess similar supramolecular assembly behavior but exhibit different PL properties. TPE-C10 not only forms self-assembly morphologies with monomer emission but also emits aggregation-induced emission (AIE). Moreover, the polymer microspheres containing TPE-C10 and Pyrene-C10 are prepared, which can dissolve or swell in different organic solvents. The changed binding effect of polymer chains achieves the luminescence transformation of TPE-C10 from AIE to monomer emission. This work hopefully can enrich luminescent materials based on the monomer emission of the TPE derivative and provide a new method for mechanism studies about supramolecular self-assembly and luminescence.

Variation of nitrate and nitrite in condensable particulate matter from coal-fired power plants under the simulated rapid condensing conditions.

In this work, condensation temperature, H2O vapor, SO2, SO3 and NH3 were studied to explore the formation mechanism of nitrate ions (NO3-) and nitrite ions (NO2-) in condensable particulate matter (CPM) discharged by ultra-low emission coal-fired power plants. Some important results were obtained: (i) The concentration of NO3- and NO2- increased with the decrease of condensation temperature, and H2O vapor could also promote the formation of NO3- and NO2-. (ii) The effects of SO2 and SO3 varied at different saturated states of flue gas, which was caused by the redox reaction of SO2 and NOX or the formation of H2SO4. (iii) NH3 could promote the nucleation of NO3- and NO2-, and the promotion effect also existed in the existence of SO2 or SO3. It is worth mentioning that SO3 and SO2 might synergistically inhibit the formation of NO3- and NO2-, regardless of the presence of NH3. The research results would enrich peoples understanding of the chemical and physical characteristics of NO3- and NO2- in CPM and provide a basic reference for the control of CPM emitted from coal-fired power plants.

Physicochemical characteristics of polycyclic aromatic hydrocarbons in condensable particulate matter from coal-fired power plants: A laboratory simulation.

The objective of this study was to examine the physicochemical characteristics of polycyclic aromatic hydrocarbons (PAHs) in condensable particulate matter (CPM) during fast condensation (within several seconds). The concentration of PAHs increased as the condensation temperature decreased, indicating that the conversion of gaseous PAHs to CPM would be enhanced at low temperatures. PAH concentrations increased in relation to the number of rings in the fragment, with the high-ring (4-,5- and 6-ring) PAHs accounting for 89.70-92.30% and 99.78-99.80% of the total concentration and total toxic equivalent of PAHs. In addition, particulate-phase PAHs (0.1-1.0 µm), developed through the synergistic effect of PAHs and fine particles, were difficult to collect by fast condensation. Inorganic fine particles could be formed when ammonia-rich conditions prevail, reducing PAH condensation further. Furthermore, CPM was morphologically and chemically characterized. During the experiment, fine and well-aggregated CPMs were detected on the membrane, and the diameter of CPMs was further enhanced by the addition of 16 PAHs. Most of the C element was collected in the rinse fluid, thus indicating that PAHs in CPM were collected through condensation. Based on these findings, basic guidelines can be provided for the control of PAHs in flue gas from coal-fired power plants.

[Conversion Characterizations of Sulfate Ion and Nitrate Ion in Particulate Matter from Coal-fired Power Plants].

The particulate matter emitted from coal-fired power plants includes condensable particulate matter(CPM) and filterable particulate matter(FPM). By analyzing the concentration of SO42-and NO3- components of CPM and FPM in the inlet/outlet of wet flue gas desulfurization(WFGD) and the outlet of wet electrostatic precipitator(WESP) from 7 ultra-low emission coal-fired power plants, the variation laws and transformation characteristics were investigated. The results showed that the concentration of SO42- and NO3- of CPM decreased after WFGD, with reduction rates of 43.12%-86.84% and 17.99%-91.58%, respectively, which were different from the conversion trend of FPM. The concentrations of SO42- and NO3- of CPM increased after WESP, with reduction rates of 21.05%-424.65% and 13.51%-298.37%, respectively, which were also different from that of FPM. In the WFGD system, CPM could be transformed into FPM due via condensation and aggregation under the decreasing temperature and increasing of humidity of the flue gas. In the WESP system, SO2 and NO2 in the flue gas combine with water vapor in a redox reaction, which promotes the generation of SO42- and NO3- in CPM through synergistic action.

[Conversion Characteristics of Combustible Particles from Coal-fired Flue Gas in WFGD and WESP].

Monitoring of condensable particulate matter (CPM) emitted from stationary pollution sources has often been neglected. To reduce the emission of CPM, it is necessary to study its transformation rules in flue-gas cleaning devices. The results show that the wet flue gas desulfurization (WFGD) and wet electrostatic precipitator (WESP) have a good synergistic effect on the removal of CPM. The concentration of CPM in flue gas is higher than that of filterable particulate matter, but the concentration of total particulate matter (sum of the condensable particulate matter and filterable particulate matter) reaches ultra-low emission requirements. The organic mass concentration of CPM in the WFGD inlet and outlet is larger than that of inorganic components, which is equalized during the treatment of WESP. Based on measurements of the components and concentrations of water-soluble ions in the inorganic part of the CPM, PM0.3 can be joined during the CPM trapping process and an acid mist is generated during the condensable particulate matter formation. The acid mist is strengthened through the treatment of WFGD and WESP. The experiment results also show that SO42- is the main component of water-soluble ions in the inorganic part of CPM.

Novel CeO2@TiO2 core-shell nanostructure catalyst for selective catalytic reduction of NOx with NH3.

The CeO2@TiO2 core-shell nanostructure catalyst prepared by a two-step hydrothermal method was used for selective catalytic reduction (SCR) of NOx with NH3 in this study. The catalyst presented the obvious core-shell structure, and the shell was amorphous TiO2 which could protect the active center from the SO2 erosion. The catalyst showed high activity and stability, excellent N2 selectivity and superior SO2 resistance and H2O tolerance. Characterizations such as TEM, HR-TEM, XRD, BET, XPS, NH3-TPD, and H2-TPR were carried out. The results indicated that the catalyst had large surface area and the active sites were well dispersed on the surface. The NH3-TPD, H2-TPR and XPS results implied that its increased SCR activity might be due to the enhancement of NH3 chemisorption and the increase of active oxygen species, both of which were conductive to NH3 activation. The excellent catalytic performance suggests that it is a promising candidate for SCR catalyst.

[Poisoning effect of Ca depositing over Mn-Ce/TiO2 catalyst for low-temperature selective catalytic reduction of NO by NH3].

Calcium carbonate (CaCO3), calcium sulfate (CaSO4), and calcium chloride (CaCl2) were chosen as the precursors to prepare the Ca salts deposited Mn-Ce/TiO2 catalysts through an impregnation method. The influence of Ca on the performance of the Mn-Ce/TiO2 catalyst for low-temperature selective catalytic reduction of NO by NH3 was investigated. Experimental results showed that Ca salts had negative effects on the activity of Mn-Ce/TiO2 and the precursors of Ca salts also affected the catalytic activity. The precursor CaCl2 had a greater impact on the catalytic activity, while CaCO3 had minimal effect. The samples were characterized by Brunner-Emmet-Teller measurements (BET), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and NH3temperature programmed desorption (NH3 -TPD). The characterization results indicated that the significant changes in physical and chemical properties of Mn-Ce/TiO2 were observed after Ca was deposited on the catalysts. The significant decreases in surface areas and NH,3adsorption amounts were observed after Ca was deposited on the catalysts, which could be considered as the main reasons for the deactivation of Ca deposited Mn-Ce/TiO,2

Influences of pH value in deposition-precipitation synthesis process on Pt-doped TiO2 catalysts for photocatalytic oxidation of NO.

This work has been undertaken to study the influences of pH value on the characteristics and activity of photocatalyst by deposition-precipitation method during its preparation process. A series of Pt-modified TiO2 were prepared by deposition-precipitation method at different pH values as well as wet impregnation method, and characterized by XRD, XPS, TEM, UV-Vis and photoluminescence (PL). It was found that the catalysts had the highest photocatalytic activity for NO conversion when pH value was kept at around 7. And the sample prepared by deposition-precipitation method showed higher activity than that by impregnation method. This was mainly due to their high value in highly-dispersed platinum oxides (PtOx) content on the surface of the catalysts. The results from UV-Vis absorption showed that highest absorbance was obtained for Pt/TiO2 prepared at pH values of around 7. And PL spectra results indicated that the recombination rate of photogenerated electrons and holes of the samples prepared by deposition-precipitation method was lower than that prepared by impregnation method. And in the zeta potential study, the pH values for the isoelectric point of the preparing slurry of 0.05 wt.%Pt/TiO2 and 0.5 wt.%Pt/TiO2 were determined to be 6.5-8.5, which further confirmed the enrichment of PtOx dopants for the catalysts repapered when pH value was around 7.

A novel co-precipitation method for preparation of Mn--Ce/TiO2 composites for NOx reduction with NH3 at low temperature.

Mn--Ce/TiO2 catalyst prepared by a novel co-precipitation method was used in this study for low-temperature selective catalytic reduction (SCR) of NOx with ammonia. The catalyst showed high activity and good SO2 resistance. The NO conversion on the catalyst increased to 100% when 700 ppm of SO2 flowed in, and reached 60.8% in 2.5 h. The characterized results indicated that the catalyst prepared by the new method had good dispersion of the active phase, uniform micro-size particles and large Brunauer-Emmett-Teller surface. The temperature programmed reduction and temperature programmed desorption experiments showed that the improvement in SCR activity on the Mn--Ce/TiO2 catalyst might be due to the increase of active oxygen species and the enhancement of NH3 chemisorption, both of which were conducive to NH3 activation.

Deactivation mechanism of PtOx/TiO(2) photocatalyst towards the oxidation of NO in gas phase.

This study has been undertaken to investigate the roles of PtO and PtO(2) deposits in photocatalytic oxidation of NO over Pt-modified TiO(2) catalysts. These photocatalysts were prepared by neutralization method and characterized by XRD, BET, XPS, TEM and FTIR. It was found that Pt dopant existed as PtO and PtO(2) particles in as-prepared photocatalysts. And these Pt dopants would change their oxidation states during the photocatalytic oxidation reaction. An in situ XPS study indicated that a portion of PtO(2) on the surface of Pt/TiO(2) was reduced to PtO under UV irradiation. The migration of electrons to PtO(2) particles could separate the electrons and holes, resulting in the improvement of photocatalytic activity. And the depletion of PtO(2) by electrons could lead to the deactivation of Pt/TiO(2) catalyst. Moreover, PtO particles could be corroded to form Pt(2+) ions by HNO(3), which was one of the products of photocatalytic oxidation of NO. NO would adsorb on Pt(2+) related sites to form Pt(n+)-NO nitrosyls, retarding photocatalytic oxidation of NO to NO(2).

Relationship between Pd oxidation states on TiO(2) and the photocatalytic oxidation behaviors of nitric oxide.

This study has been undertaken to investigate the relationship between Pd oxidation states on TiO(2) photocatalysts and their photocatalytic oxidation behaviors of NO. Three types of Pd-modified TiO(2) with different Pd oxidation states were prepared by wet impregnation method, neutralization method and photodeposition method, respectively. And these Pd-modified photocatalysts were characterized by X-ray diffraction analysis, X-ray photoelectron spectrum analysis (XPS), UV-Vis diffuse reflectance spectra and temperature programmed desorption (TPD). It was found from XPS results that the dominant oxidation states of Pd on these Pd-modified TiO(2) catalysts were Pd(2+), PdO, and Pd(0), respectively. NO-TPD results showed that the NO adsorption capacity was improved greatly by the modification of Pd(2+) ions. The activity tests showed that Pd-modified TiO(2) by a wet impregnation method increased photocatalytic activity compared to pure TiO(2) (Degussa P25). It was concluded that Pd(2+) ions on as-prepared TiO(2) catalysts provided key contributions to the improvement of photocatalytic activity. However, Pd(0) and PdO deposits on TiO(2) almost had no positive effect on NO oxidation. The mechanism of photocatalytic oxidation of NO in gas phase over Pd-modified TiO(2) was also proposed.

Characterization and activity of Pd-modified TiO2 catalysts for photocatalytic oxidation of NO in gas phase.

Pd-modified TiO(2) prepared by thermal impregnation method was used in this study for photocatalytic oxidation of NO in gas phase. The physico-chemical properties of Pd/TiO(2) catalysts were characterized by X-ray diffraction analysis (XRD), Brunauer-Emmett-Teller measurements (BET), X-ray photoelectron spectrum analysis (XPS), transmission electron microscopy (TEM), high resolution-transmission electron microscopy (HR-TEM), UV-vis diffuse reflectance spectra (UV-vis DRS) and photoluminescence spectra (PL). It was found that Pd dopant existed as PdO particles in as-prepared photocatalysts. The results of PL spectra indicated that the photogenerated electrons and holes were efficiently separated after Pd doping. During in situ XPS study, it was found that the content of hydroxyl groups on the surface of Pd/TiO(2) increased when the catalyst was irradiated by UV light, which could result in the improvement of photocatalytic activity. The activity test showed that the optimum Pd dopant content was 0.05 wt.%. And the maximum conversion of NO was about 72% higher than that of P25 when the initial concentration of NO was 200 ppm, which showed that Pd/TiO(2) photocatalysts could be potentially applied to oxidize higher concentration of NO.

[Expression of lethal gene mRNA on placenta villi in patients with spontaneous abortion].

OBJECTIVE: To study the role of lethal gene: including retinoic X receptor (RXR)alpha, N-myc and transcript enhancer factor (TEF)-1 in human spontaneous abortion. METHODS: The levels of RXRalpha, N-myc and TEF-1 mRNA expression on placenta villi from 38 spontaneous abortion women and 33 normal early pregnant women were examined by reverse transcription, polymerase chain reaction. RESULTS: (1) The levels of RXRalpha mRNA on placenta villi from the abortion group were significantly decreased as compared with those from normal group (0.4 +/- 0.3 versus 0.6 +/- 0.3, P < 0.05); There were no significant differences in the levels of N-myc mRNA expression between the abortion group and normal group (2.1 +/- 1.2 versus 2.2 +/- 0.9, P > 0.05). The levels of TEF-1 mRNA on placenta from abortion group were significantly lower than those from normal group (1.6 +/- 1.1, 2.3 +/- 1.2, P < 0.05); (2) The levels of RXR alpha mRNA, TEF-1 mRNA in recurrent abortion group were significantly lower than those from non-recurrent group (0.3 +/- 0.2 versus 0.6 +/- 0.4, P < 0.05, 1.0 +/- 1.1 versus 1.9 +/- 1.2, P < 0.05). CONCLUSION: It was suggested that the lower expression of RXR alpha mRNA, TEF-1 mRNA may play an important role in the pathogenesis of spontaneous abortion especially in recurrent abortion.