以Keggin结构杂多阴离子掺杂的聚吡啶的化学合成及性能研究

以12-钼磷酸和12-钨磷酸为掺杂剂,用化学方法合成了两种导电聚合物:聚吡啶/PMo12和聚吡啶/PW12,用IR、UV-Vis对聚合物进行了表征,并研究了其氧化还原特性及导电性,两种聚合物均具有较好的氧化还原可逆性,室温固体电导率分别为0.6 s·cm-1和0.5 s·cm-1.     

镁合金钼酸盐、钼酸盐-磷酸盐转化膜的研究

研究了镁合金表面钼酸盐转化膜以及钼酸盐-磷酸盐复合转化膜,探讨了两种转化膜的组成、形态、极化曲线及耐盐水腐蚀性。发现钼酸盐-磷酸盐转化膜微观表面呈均匀"蜂窝"状,较单一的钼酸盐转化膜具有更好的耐腐蚀性。     

石墨烯复合金属离子掺杂纳米二氧化钛光催化材料的研究进展

对石墨烯复合金属离子掺杂纳米二氧化钛光催化材料在污染物治理、CO₂还原和资源化、H₂生产等方面的研究进展进行了论述。石墨烯复合金属离子掺杂纳米二氧化钛光催化材料相较于纳米二氧化钛,其禁带宽度变窄,提高了在可见光区的吸收性能,提高了光催化活性,提高了污染物降解率、CO₂还原和资源化的产率和H₂生产效率。     

钯负载锰氧化物基双金属复合氧化物催化氧化羰基化合成碳酸二苯酯

采用共沉淀法分别制备锰掺杂钨、钒、铋3种双金属复合氧化物载体,以氯化钯为活性组分制备负载型催化剂,并用于苯酚氧化羰基化合成碳酸二苯酯（DPC）。通过气相色谱（GC）、X射线衍射（XRD）、氢气程序升温还原（H₂-TPR）、X射线光电子能谱（XPS）等表征手段,对催化剂结构和性能进行表征。结果表明:钨-锰载体随掺杂比例和焙烧温度升高,逐步形成四氧化三锰晶粒,同时钨渗入锰氧化物晶格中,在掺杂比（物质的量比）为1:1、焙烧温度为600 ℃条件下制备的催化剂性能最佳,DPC收率为5.20%;钒-锰载体在焙烧温度为400 ℃、掺杂比为1:5条件下形成二氧化锰晶相,催化剂性能明显提高,DPC收率为10.46%,而较高的焙烧温度会破坏晶型的完整;铋-锰载体在掺杂比为1:5、焙烧温度为400 ℃条件下制备的催化剂催化效果最好,DPC单程收率可达到13.13%。     

研究与述评

通过化学氧化聚合法合成了掺杂了磷酸盐和硝酸盐的聚吡咯传吕粉复合颜料。一种涂料配方中含有掺杂了磷酸盐的聚吡咯腾吕粉复合颜料、掺杂了硝酸盐的聚吡咯／铝粉复合颜料,其中铝粉的颜料体积溶度为20％。     

混配型杂多钼酸催化乙醇制乙醛的研究

<正> 杂多酸(盐)是一类具有确定组成的含有氧桥的多核配合物,目前在理论和应用中研究得最多的是钼、钨杂多酸(盐),它们既具有配合物和金属氧化物的结构特征,又兼有酸性和氧化还原性能。分子量较大的钼、钨杂多酸阴离子呈笼状结构。鉴于它们的这些特点,钼、钨杂多酸(盐)在催化领域中的应用     

导电高分子的应用

介绍了导电高分子的分类，并从导电高分子的氧化还原性、电化学性、掺杂-脱掺杂性等方面讨论了导电高分子在多种领域的应用。     

镁合金钼酸盐/磷酸盐复合转化膜的制备

研究了镁合金钼酸盐/磷酸盐复合转化膜,分析了影响复合转化膜性能的因素.结果表明:当钼酸盐/磷酸盐复合转化液pH值为5,n(MoO2-4)/n(H2PO-4)为1/2时,镁合金钼酸盐/磷酸盐复合转化膜腐蚀电流最低,耐蚀性能较好,微观表面呈均匀"蜂窝"状,具有最佳防腐蚀性能;并且当Ca2 和Mn2 同时存在时,膜层的极化电阻最大.     

钼掺杂锰分子筛催化合成环氧大豆油的研究

以高锰酸钾、硫酸锰为锰源,钼酸钠为钼源,采用一步回流法制备钼掺杂锰分子筛催化剂(Mo-OMS-2)。利用X射线粉末衍射(XRD)、程序升温还原(H2-TPR)和吡啶探针红外光谱等方法对催化剂进行表征。在不使用溶剂的条件下以叔丁基过氧化氢为氧化剂研究了钼掺杂锰分子筛催化剂在大豆油环氧化反应中的性能,考察了氧化剂用量、反应时间、加料顺序等因素对大豆油环氧化反应的影响。结果表明:钼的掺杂改变了锰分子筛的氧化还原性质和表面Lewis酸性,使得催化剂的催化性能发生了明显改变;在不添加溶剂的条件下,以10%Mo-OMS-2为催化剂,将6.0 g叔丁基过氧化氢滴加到底料中在65℃反应2 h,所得产品的环氧值高达1.687%。     

酸性溶液中钨钼离子的电化学行为

为加大钨钼电化学性质的差异实现钨钼分离,使钨钼形成钨磷、钼磷杂多酸,采用循环伏安法研究酸性条件下含钨钼溶液及钨磷、钼磷杂多酸的电化学行为,获得多种溶液体系的循环伏安曲线. 结果表明,研究体系中钨的还原电位较钼高,但二者电位差小于0.1 V,无法利用电化学性质差异高效分离;而将钨和钼形成杂多酸体系后,钼磷杂多酸还原峰电位为0.401 V,钨磷杂多酸为0.1949 V,加入磷酸增大了钨钼离子电位差,可优先将钼还原.     

45#钢在磷酸盐颜料提取液中的电化学行为

用开路电位法、Tafel极化曲线、EIS等方法研究了45#钢在不同pH的磷酸锌、APW-I及两种复合掺杂磷酸盐颜料3.5%NaCl水提取液中的电化学行为。研究结果表明:两种复合掺杂磷酸盐颜料在不同酸碱度条件下,均显示出异常优异的腐蚀抑制性能,且是以抑制阳极为主的防锈颜料;碱性体系下,传统磷酸盐颜料APW-I的结果较为优越。     

Oxidation activity of iron phosphate and its characters

Iron phosphate catalysts possess a unique selectivity to oxidative dehydrogenation. Unlike ordinary catalysts consisting of molybdenum and/or vanadium, they have no double-bond oxygen species (M=O) that are considered to be responsible for the oxygen insertion function and, as a result, for the degradation by C–C bond fission. The defect of iron phosphate catalysts is a lack of oxidation activity. Addition of a very small amount of molybdenum into iron phosphate enhances markedly the oxidation activity without modifying the high selectivity originated from iron phosphate. The marked increase in the activity is ascribable to an increase in the reducibility of iron phosphate, because the reoxidizability of iron phosphate is high enough. It is proposed that the reaction over a Mo-doped iron phosphate is promoted by redox cycle of iron phosphate but not by that of molybdenum phosphate.     

不同组成磷酸盐颜料的腐蚀抑制性能

以铬酸锌为参照物,考察了45#钢在不同pH值3.5%NaCl的磷酸盐颜料提取液腐蚀体系下的电化学行为,讨论了传统和新型复合掺杂磷酸盐颜料的腐蚀抑制特性。结果表明,AlZnPO4MoO4.4H2O和AlZn2P3O10-(MoO4)2.2H2O两种新型复合掺杂磷酸盐颜料在不同酸碱度条件下均展现出较为理想的效果,尤其是很好的改善了传统磷酸盐在中性体系中的防腐性能,甚至超过了性能优异的铬酸锌颜料,同时,进一步提升了酸性环境下磷酸盐颜料所具有的优越性。     

Synthesis of high-performance electrochromic thin films by a low-cost method

Metal-doping is an effective method to adjust the physical and chemical properties of semiconductor metal oxides. This work adopts a simple solvothermal method to synthesize Mo-doped tungsten oxide nanoparticles. The high-performance electrochromic films can be homogenously formed on ITO glass without post-annealing. Compared with pure WO₃ films, the optimized Mo-doped WO₃ films show improved electrochromic properties with significant optical contrast (68.3% at 633 nm), the short response time (6.3 s and 3.9 s for coloring and bleaching, respectively), and excellent coloration efficiency (107.2 cm² C^?1). The improved electrochromic behavior is mainly due to the increasing diffusion rate of Li⁺ in Mo-doped WO₃ films (increased 20% than that of pure WO₃ films). The porous surface of Mo-doped WO₃ film shortens the diffusion path of Li⁺. Besides, Mo doping reduces the resistance and improves conductivity. Furthermore, 2at% Mo-doped WO₃ films indicate satisfactory energy-storage properties (the specific capacitance is 73.8 F g^?1), resulting from the enhanced electrochemical activity and fast electrical conductivity. This work presents a practical and economical way of developing high-performance active materials for bifunctional electrochromic devices.     

Oxidation–Reduction Equilibrium in Copper Phosphate Glass Melted in Air

Copper phosphate glasses with 40, 50, and 60 mol% CuO in batch were melted in air at 1000°, 1100°, and 1200°C using quartz or alumina crucibles, and the [Cu²⁺]/[Cu_total] ratio variations with melting time were measured. Glasses were oxidized during melting and reached equilibrium [Cu²⁺]/[Cu_total] ratios which were independent of melting temperature and identical for the 40 and 50 mol% CuO content glasses. Structural considerations seemed to have determined oxidation-reduction equilibrium rather than an equilibrium redox reaction. Also, the effects of crucible type on the oxidation-reduction balance were examined. It was found that a quartz crucible is more inert and has less effect on the oxidation-reduction equilibrium of glass than an alumina crucible. Crucible contamination and phosphorus vaporization were found to diminish as the CuO content in the batch was increased.     

Multifold stiffness and fracture toughness enhancement in W-doped VO2 microcrystals

Vanadium dioxide is popular for the metal-insulator phase transition at 68°C. Chemical doping is one of the effective ways adopted to tune the phase transition temperature, where tungsten is known to reduce the transition temperature of VO₂. This work investigates the effect of tungsten doping on the mechanical properties of VO₂ microcrystals and their polymer composites. Doping of VO₂ with W shows a systematic reduction in phase transition temperature up to 33°C for 4 wt% W-doped VO₂. For 3 wt% W-doped VO₂, the elastic modulus values enhance by 50%. The fracture toughness of 3 wt% W-doped VO₂ shows an enhancement of fourfold compared to the undoped VO₂. The dynamic compressive strength of 3 wt% W-doped VO₂–UHMWPE polymer composite at room temperature is found to be 7% higher than the undoped VO₂—composite.     

Preparation and optical properties of W-doped VO2/AZO bilayer composite film

In order to improve its visible light transmittance, W-doped VO₂ thin film was prepared with direct current (DC) reactive magnetron sputtering on the surface of Al-doped ZnO (AZO) thin film deposited on quartz glass substrate in advance with radio frequency (RF) magnetron sputtering. The effects of sputtering power for AZO film were investigated on the crystal structures, surface morphologies and optical properties of AZO thin film and W-doped VO₂/AZO bilayer composite film. The results show that the crystallinity of both AZO monolayer film and the bilayer film first increases and then decreases with the increase of sputtering power. As the sputtering power increases, the film thickness increases. The integral visible luminous transmittance (T_lum) of the W-doped VO₂/AZO bilayer film decreases continuously, and the solar modulation efficiency (ΔT_sol) increases first and then decreases. When the sputtering power is 150 W, T_lum and ΔT_sol of W-doped VO₂/AZO bilayer film are 30.14% and 11.95%, 2.77% and 1.71% higher than those of W-doped VO₂ monolayer film, respectively.     

Mn-P共掺杂氮化碳的制备及其光催化性能研究

采用四水氯化锰、磷酸氢二铵和三聚氰胺为原料制备了Mn-P共掺杂的石墨相氮化碳(g-C3 N4).使用X射线衍射光谱(XRD)、扫描电子显微镜(SEM)、傅里叶变换红外光谱(FT-IR)、光致荧光光谱(PL)、紫外-可见漫反射光谱(UV-Vis DRS)、电化学阻抗谱(EIS)、瞬态光电流响应等分析测试手段对制备的催化剂...     

Co-doping g-C3N4 with P and Mo for efficient photocatalytic tetracycline degradation under visible light

Although g-C₃N₄ (CN) materials have been extensively explored for the photocatalytic degradation of organic pollutants, their weak response to visible light and fast recombination of photoexcited electron-hole pairs restrain their practical applications. Herein, we deeply mediated the CN's energy-band structure, morphology, and surface properties by non-metal (P) and metal (Mo) co-doping based on the thermal treatment of a phosphomolybdic acid hydrate and dicyandiamide mixture in a straightforward one-step manner. Meanwhile, cyano groups and nitrogen vacancies were generated as a result of the co-doping, and the resulting P, Mo co-doped CN (PM-CN) exhibited thinner layers, smaller sizes, and superior visible-light harvesting capacity and charge separation efficiency. Consequently, highly active PM-CN was obtained for photocatalytic tetracyclines (TC) degradation, and the rate was calculated to be 0.01 min^?1, 3.3 times greater than that of the pure CN, outstripping the single P- and Mo-doped counterparts. A free radical scavenging test demonstrated that the reactive species ?O^2? and h⁺ were critical in TC degradation. The present work is expected to shed light on co-doping CN with non-metal and metal elements to obtain high-performance, visible-light-responsive photocatalysts for practical environmental remediation.     

Low-temperature Maxwell-Wagner relaxation in (Na + Nb) co-doped rutile TiO2 colossal permittivity ceramics

The exact mechanism of the stunning colossal permittivity behavior found in (donor-acceptor) co-doped TiO₂ system still remains enigmatic. This behavior results from a thermally activated dielectric relaxation occurring below 50 K. Herein, thermally stimulated depolarization current analysis combined with dielectric investigation was used to disentangle this relaxation in (Na + Nb) co-doped TiO₂ ceramics. We find that this relaxation is related to frozen electrons and features the Vogel-Fulcher behavior and negative dielectric tunability. Our results reveal that this low-temperature relaxation is a new kind of Maxwell-Wagner relaxation. Differences between the low-temperature Maxwell-Wagner relaxation and its high-temperature counterpart are discussed. This study provides new insights into the physics of the eye-catching dielectric properties in co-doped TiO₂ system.