3D cross-linked BiOI decorated ZnO/CdS nanorod arrays: A cost-effective hydrogen evolution photoanode with high photoelectrocatalytic activity

ZnO/CdS photoanode with an excellent photoelectrochemical (PEC) performance for water splitting to produce hydrogen, but its practical application is seriously hindered owing to the photocorrosion induced by photoholes on the surface of CdS. Herein, a 3D cross-linked heterostructure ZnO/CdS/BiOI nanorod arrays (NRAs) has been prepared by a simple solvothermal strategy. Under visible light illumination (λ > 420 nm), the ZnO/CdS/BiOI NRAs photoanode shows an excellent PEC activity and generates a photocurrent density of 9.12 mA cm⁻² at 1.1 V vs. RHE, which is 1.8 times higher than that of the ZnO/CdS NRAs photoanode in the alkaline electrolyte. Furthermore, the photoanode achieves a high photo conversion efficiency of 3.49% and a long-time stability over 6000 s. It is proposed that the BiOI nanosheets not only serve as protecting layer to restrain the photocorrosion of CdS, but also facilitate the charge separation in CdS by the virtue of the p-n junction formed between CdS and BiOI.     

微波和超声波辅助提取穿心莲内酯

用正交法对微波和超声波辅助提取穿心莲内酯的工艺条件进行优化。微波辅助法提取穿心莲内酯的最佳工艺条件为温度40℃、提取溶剂为体积分数75%的乙醇、提取时间8 min;超声波辅助法提取穿心莲内酯的最佳工艺条件是提取溶剂为体积分数75%的乙醇,超声效率40%、超声时间50 min。微波提取法的平均回收率为99.9%,RSD为0.31%;超声波提取法的平均回收率为100.5%,RSD为0.21%。与超声波提取法相比,微波提取法提取时间较短,提取得率较高。     

N-(歧化松香基)丙烯酰胺聚合物的合成研究

以歧化松香胺、丙烯酸为原料,在催化剂五氧化二磷的作用下先合成N-(歧化松香基)丙烯酰胺;然后在催化剂三氯化铝的作用下催化聚合得到N-(歧化松香基)丙烯酰胺聚合物,通过紫外及红外光谱分析其结构,测定了N-(歧化松香基)丙烯酰胺聚合物的溶解度、分子量、微孔结构及热稳定性,并讨论了制备N-(歧化松香基)丙烯酰胺、N-(歧化松香基)丙烯酰胺聚合物的合成条件.     

水热碳化法制备淀粉碳化物/海泡石(St-Sep)复合材料的优化

以木薯淀粉和天然海泡石为原材料,制备了新型淀粉碳化物/海泡石(St-Sep)复合材料,用真空冷冻干燥器干燥样品,并利用响应面法优化了制备工艺.利用水热碳化法制备了St-Sep复合材料,并利用X射线衍射仪(XRD)和傅里叶红外变换光谱仪(FTIR)对材料的结构进行表征,证明了St-Sep的成功合成.进一步用扫描电镜(SE...     

Computational simulation of adsorption and thermodynamic study of xanthate,dithiophosphate and dithiocarbamate on galena and pyrite surfaces

Computer modeling and the microcalorimetry method were employed to investigate the adsorption of xanthate, dithiophosphate (DTP) and dithiocarbamate (DTC) on the galena and pyrite surfaces. The calculated results show that the pyrite surface undergoes greater relaxation than galena, while galena has a more electronegative surface than pyrite. The pyrite Fe atom is more active than the galena Pb atom. The simulations of adsorption show that the adsorbates coordinate mainly to the surfaces through interaction between their S atoms with the surface Pb or Fe atoms. The analysis of the density of states (DOSs) suggests that the adsorption of xanthate on the pyrite surface is stronger than that on the galena surface, while that of DTP and DTC are stronger on the galena surface than on the pyrite surface.The heat of adsorption and kinetics parameters of DTC and DTP at the galena and pyrite surfaces differ greatly, suggesting that DTC and DTP exhibit good selectivity in the separation of pyrite and galena, while these two parameters for xanthate at the two minerals differ little, indicating the poor selectivity of xanthate.     

Study of H2O adsorption on sulfides surfaces and thermokinetic analysis

Adsorption of water on mineral surfaces was studied using density functional theory and microcalorimetry technique. The calculation results show that galena and molybdenite are hydrophobic, while pyrite and sphalerite is hydrophilic. Thermokinetic analysis shows that the heat of adsorption is in decreasing order of pyrite, sphalerite, galena and molybdenite, which is in good agreement with the calculation results. The adsorption kinetics parameters of hydrophobic galena and molybdenite surfaces are close, while those of hydrophilic pyrite and sphalerite surfaces are very different. The adsorption rate of water on the sphalerite surface is larger than that of water on the pyrite surface.     

葡萄糖碳化物/海泡石复合材料制备工艺及响应面法优化

以葡萄糖和天然海泡石为原材料,利用水热碳化法制备了新型葡萄糖碳化物/海泡石复合材料,冷冻真空干燥法干燥样品。利用X射线衍射分析(XRD)、红外吸收光谱(IR)、扫描电镜(SEM)、比表面积(BET)对样品进行了表征,选择亚甲基蓝作为吸附质考察其吸附性能,并通过单因素和响应面法优化了材料制备的工艺。实验结果表明,复合材料制备最优工艺条件为:葡萄糖与海泡石质量比为1.49∶1.0、碳化时间为7.33 h(440 min);碳化温度为175℃,对亚甲基蓝的最优吸附量为45.22 mg/g;各因素对复合材料吸附亚甲基蓝性能的影响顺序为:碳化时间>碳化温度>葡萄糖与海泡石质量比。     

Facile preparation of heterostructured Bi2O3/Bi2MoO6 hollow microspheres with enhanced visible-light-driven photocatalytic and antimicrobial activity

Hierarchical β-Bi₂O₃/Bi₂MoO₆ heterostructured flower-like microspheres assembled from nanoplates with different β-Bi₂O₃ loadings (0–26.5 mol%) were synthesized through a one-step template-free solvothermal route. Under visible-light illumination (λ > 420 nm), over 99% of rhodamine B was degraded within 90 min on the 21.9 mol% of β-Bi₂O₃ loading Bi₂O₃/Bi₂MoO₆ microspheres. The remarkable enhancement of photocatalytic activity of the hierarchical Bi₂O₃/Bi₂MoO₆ micro/nanostructures can be attributed to the effective separation of the photoinduced charge carriers at the interfaces and in the semiconductors. The electrons (e⁻) are the main active species in aqueous solution under visible-light irradiation. The Bi₂O₃/Bi₂MoO₆ also displays visible-light photocatalytic activity for the destruction of E. coli. In addition, the β-Bi₂O₃ in the hierarchical Bi₂O₃/Bi₂MoO₆ microspheres is very stable and the composite can be easily recycled by a simple filtration step, thus the second pollution can be effectively avoided. A possible photocatalytic mechanism was proposed based on the experimental results.     

Viscosity transition of ZnO-containing rosin

Eutectic alloy Sn–9Zn is regarded as one of the potential substitutes for Pb-containing solders, although it has some drawbacks yet to overcome. One of the problems involved is drastic viscosity increase of rosin-based flux during soldering or storage. In the present work we investigated the role of ZnO in the viscosity transition of rosin. The results show that the viscosity transition is directly caused by the presence of ZnO in molten rosin and, at a certain temperature, there exists a critical ZnO concentration for its occurrence. The critical ZnO concentration increases with temperature. A graph is presented to show the conditions for the viscosity transition, in a ZnO concentration–temperature space. The transition is found to be reversible when shifting temperature or ZnO concentration across the boundary and to assume the features of a thermally activated phase transformation.     

Synthesis of NH4FePO4·H2O nano-plates via solid-state reaction at low temperature and its thermochemistry properties

Ammonium-iron(II) phosphate monohydrate was synthesized via solid-state reaction at low temperature and characterized by X-ray diffraction, infrared spectroscopy, chemical analysis and scanning electron microscope. Thermochemical study was performed by an isoperibol solution calorimeter at 298.15 K. The results show that the obtained product is NH₄FePO₄·H₂O with plate shape of nanometer measure. According to Hess's law, a new thermochemical cycle was designed, and the standard enthalpy of formation of the titled complex at 298.15 K is .