Cu/WO_3-NiO上光促表面催化二氧化碳与水合成甲醇反应的规律

采用溶胶 凝胶法制备了n p复合半导体材料 0 75 %Cu/WO3 1 5 %NiO ,用X射线衍射、透射电镜、红外光谱、紫外 可见光漫反射和程序升温脱附等技术对材料结构、吸光性能和化学吸附性能进行了表征 ,研究了该材料对CO2 与H2 O合成CH3OH的光促表面催化反应 (PSSR)规律 .结果表明 :所制备的材料明显有利于促进目的反应 ,室温条件下就有CH3OH生成 ,选择性超过 90 % ,升高反应温度可提高CH3OH产量 ,且选择性仍高于 88% .根据实验结果 ,得出CO2 在材料表面的卧式吸附态为CH3OH的前驱物 。

核-壳结构Cu/Al微纳米复合材料与WO_3的热反应性能

采用置换法通过对溶液浓度的控制实现了纳米Cu颗粒在微米Al粉表面定量、快速地化学沉积,制备出核一壳结构的Cu/Al微纳米复合粒子,并用SEM、EDS和XRD技术进行表征.在此基础上,利用DSC分析了Cu/ Al-WO_3的热反应性能,对比了Al-WO_3与Cu/Al-WO_3在不同化学配比下的热反应历程,同时分别提出了其相应的反应机理.实验结果表明,Cu/Al微纳米复合材料与WO_3的热反应活性明显高于传统微米级Al粉,并且在还原剂Cu/Al轻微过量时该热反应达到最佳效果.通过对Al粉表面改性,热反应的活化能降低了68.185 kJ·mol^(-1).

Cu-g-C_3N_4/WO_3可见光下降解四环素的性能研究

以尿素、氯化铜和偏钨酸铵为原料制备了Cu-g-C_3N_4/WO_3新型异质结构催化剂,降解水体中盐酸四环素污染物。对制备的催化剂进行了XRD、SEM、UV-Vis、PL表征,从晶型结构、表面形貌、光电性能方面分析改性g-C_3N_4降解效果提高的原因。此外,以LED灯模拟可见光源,考察了不同WO_3复合量、催化剂投加量、污染物初始浓度及溶液pH对盐酸四环素降解效果的影响,并探究了降解反应机理。结果表明WO_3与Cu-g-C_3N_4进行了简单物理复合,Cu-g-C_3N_4包裹在WO_3表面并形成Z型异质结构,影响了g-C_3N_4的能带结构,增强了可见光的吸收,降低了电子-空穴对的复合。当mWO_3∶mCu-g-C_3N_4=5%,pH=5时降解效果最佳,此外催化剂投加量越高、盐酸四环素浓度越低,降解效果越好,反应过程中主要活性基团为空穴、·O-2和·OH。

表面活性剂对电沉积纳米WO3-Cu复合镀层组织及其性能的影响

为了解不同表面活性剂对纳米复合电沉积过程的作用,研究常用的阴离子、阳离子和非离子表面活性剂对WO3-Cu复合镀层电沉积过程的影响。采用扫描电子显微镜和能谱分析仪分析添加表面活性剂前后镀层表面微观形貌和镀层成分的变化,通过润湿性试验、自清洁试验、耐磨性试验和光催化试验分别评价表面活性剂对WO3-Cu复合镀层润湿性能、自清洁性能、耐磨性能和光催化性能的影响。结果表明:表面活性剂可有效改变WO3纳米颗粒在镀层中的沉积和镀层的表面形貌,其中阳离子和非离子表面活性剂联合添加时制备的复合镀层中WO3含量达到最高值25.9%;经氟化处理后,其镀层表面接触角可达155°;与纯铜相比,复合镀层有良好的自清洁性、耐磨性和光催化性。

The Synergistic Antibacterial Performance of a Cu/WO₃-Added PTFE Particulate Superhydrophobic Composite Material

The synergistic antibacterial performance against Escherichia coli (E. coli), Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) of a Cu/WO3-added PTFE (polytetrafluoroethylene) particulate composite was reported in the previous paper. The origin of the synergistic antibacterial performance investigated by evaluating the photocatalytic decomposition of the Cu/WO3-added PTFE particulate composite material is reported in the present paper. Addition of Cu/WO3, visible-light-sensitive photocatalyst, to the PTFE particle dispersed superhydrophobic composite does not deteriorate the superhydrophobic property of the composite. Furthermore the existence of the polytetrafluoroethylene (PTFE) particles dispersed in the composite enhances the antibacterial property caused by the Cu/WO3. The authors call this “The synergistic effect”. In this study, a novel synergistic property of the Cu/WO3-added PTFE particulate composite was investigated by evaluating the degradation of gaseous acetaldehyde on the composite surface using visible light (10,000 lx) and UV-A (1 mW·cm-1) illumination. The 12 wt% Cu/WO3-8 wt% binder-80 wt% PTFE composite shows the synergistic visible-light-sensitive photocatalytic property. But 12 wt% Cu/WO3-44 wt% PTFE-44 wt% binder composite no longer shows the synergistic property of visible-light-sensitive photocatalytic property. The synergetic performance of visible-light-sensitive photocatalytic property appears only when PTFE concentration is larger than the critical point over which superhydrophobic property appears in accordance with the particulate composite model derived by the one of the authors. The hydrophobic surface leads to the low surface free energy derived by the revised Fowkes’s theory, which makes it difficult for bacteria to stick to the hydrophobic surface of the composite. Even if bacteria stick to the surface, they are decomposed by the visible-light-sensitive photocatalyst. This is the reason why the synergistic antibacterial performance against bacteria appears.

Synergistic Antibacterial Performance of a Cu/WO₃-Added PTFE Particulate Superhydrophobic Composite under Visible-Light Exposure

Addition of TiO2 to a polytetrafluoroethylene (PTFE) particle-dispersed composite contributes to the self-cleaning properties of the water-repellent composite. However, its application is limited to outdoor usage or under ultraviolet (UV) irradiation. In this study, a novel visible-light-sensitive photocatalytic and superhydrophobic material was developed by adding Cu/WO3 to a PTFE particulate composite material to overcome this deficit. A remarkable property of this novel composite material is the synergistic antibacterial performance against Escherichia coli (E. coli), Staphylo-coccus aureus, and methicillin-resistant Staphylococcus aureus compared with the addition of Cu/WO3 without PTFE particles material. During 24-h exposure in visible light at 2000 lx, the number of viable cells of the three strains on the surface of the 8wt% Cu/WO3-added PTFE particulate composite decreased from 2 – 4 × 105 colony-formation units (CFUs) to less than 10, the limit of detection. This bactericidal rate is four times higher than that of 8wt% Cu/WO3 without PTFE particles material, which is attributed to the air trapped in the rough surface of the novel material providing additional oxygen to the photocatalytic reaction. Even for exposure to visible light at 100 lx, the decrease in CFUs of E. coli on the 12wt% Cu/WO3-added PTFE particulate composite reached nearly 2.0 logs. The characterization of the Cu/WO3-added PTFE particulate composite indicated that the composite material containing 80wt% PTFE maintained a superhydrophobic or water-repellent property with a water contact angle >150。, although the Cu/WO3 in the composite material remained hydrophilic under visible light. The Cu/WO3-added PTFE particulate composite displayed photo-catalytic reactions to decompose oleic acid adsorbed on its surface and gaseous acetaldehyde under UV-A and visible-light illumination. All results demonstrate that the Cu/WO3-added PTFE particulate composite material may be used in sterilization, as a water repellent, for self-cleaning, and in the oxidative decomposition of volatile organic compounds (VOC) both indoors and outdoors.

基于单质法合成直接Z型CuS-WO_3及光催化性能

以Cu粉和S粉作为CuS前驱体,基于单质法在低温下原位合成了CuS-WO_3光催化剂。采用X射线衍射(XRD)、扫描电镜(SEM)、X射线光电子能谱(XPS)、比表面积和紫外-可见漫反射光谱(UV-Vis DRS)对CuS-WO_3的晶相、形貌、粒径及光学性质等进行了表征。结果表明,CuS对WO_3的晶相结构、粒径及比表面积没有明显影响,但是可以有效提高WO_3对可见光的吸收。以降解罗丹明B(Rh B)为反应模型,研究了CuS对WO_3光催化性能的影响。结果表明,在可见光照射下,CuS-WO_3复合材料的光催化活性优于CuS、WO_3的光催化活性,且CuS的含量对CuS-WO_3光催化活性影响显著,CuS含量为7%(w,质量分数)时,光催化效率最高(91.3%)。进一步结合CuS、WO_3的能带位置,荧光光谱(PL)活性物种鉴定试验,提出CuS-WO_3复合光催化剂的"直接Z型"光催化机理。直接Z型CuS-WO_3复合光催化剂中可以有效抑制电子-空穴的复合。因此,与CuS和WO_3相比,CuS-WO_3复合光催化剂具有较高的光催化性能。

Cu掺杂WO_3纳米棒的制备及其对正丁醇的气敏响应

通过水热法简易的制备出Cu掺杂WO_3纳米棒材料,并运用XRD、SEM、BET等手段对其物相、形貌和比表面积等进行了表征,并研究了其对正丁醇的气敏性能。气敏测试结果表明,所制备的Cu掺杂WO_3纳米棒材料对正丁醇具有良好气敏性能。当工作温度为400℃时,Cu掺杂WO_3材料对100ppm的正丁醇的响应达到了29,约为纯WO_3的3倍。同时,Cu掺杂WO_3材料对正丁醇的检测限可低至0.1ppm,并且对正丁醇还具有良好的选择性。最后对所制备的Cu掺杂WO_3材料进行了气敏机理解释。

顺序浸渍法制备V-W/x(Mn-Ce-Ti)/y(Cu-Ce-Ti)/堇青石urea-SCR催化剂及其性能研究(英文)

用溶胶凝胶法制备了Mn-Ce/TiO2(用M表示)和Cu-Ce/TiO2(用C表示)催化剂,将M相、C相和V2O5-WO3(用V表示)用顺序浸渍法依次负载到堇青石蜂窝陶瓷载体(CC)上。用尿素选择性催化还原NOx(SCR)的转化率作为衡量指标对一系列的整体催化剂性能进行评价。催化剂的物理化学性能用N2吸附、CO2-TPD、NH3-TPD、XRD、XPS和H2-TPR等进行表征。结果表明,当M相优先于C相负载到CC上时,在0.01%SO2和10%H2O存在的情况下,V/3C/3M/CC复合催化剂仍比C相或M相单独负载到堇青石上表现出较高的活性,并且微量的SO2有利于催化剂活性的提升。XRD分析结果表明,Cu-Ce负载到TiO2溶胶上有助于锐钛矿相的形成,Mn-Ce负载到TiO2上有助于金红石相的形成。比表面积只与M或C相的负载量有关而与负载顺序无关。M或C相能够增加催化剂表面不同强度的酸性位。H2-TPR研究结果表明,V和Cu或Mn之间的相互作用提高了V的还原能力,进而增加了耗氢量。由XPS分析可知,催化剂表面较高的V4+/V5+比值和大量化学吸附氧的存在有利于催化剂活性的提升。

某高硫铜、锌、钨多金属矿选矿试验研究

某铜、锌、钨多金属矿,含硫量高,磁黄铁矿较多,锌矿物氧化率大于20%,给锌硫分离和白钨浮选带来很大的困难。研究采用优先浮铜-磁选-浮锌-浮硫,浮硫尾矿再进行白钨回收的工艺流程,选择了适宜的药剂用量,在原矿含铜0.47%、含锌0.91%、含钨0.51%、含硫21.51%的条件下,取得了获得铜精矿含铜22.89%,回收率89.21%;锌精矿含锌45.55%,回收率74.02%;白钨精矿含钨50.86%,回收率78.95%;硫的总回收率为93.06%的指标。为该矿山多金属矿石的综合开发利用提供了重要的技术依据。

湖北某复杂多金属铜硫钨矿石综合回收试验研究

针对湖北某多金属铜硫钨矿石特点,通过系统的条件试验研究,确定了最佳分选工艺流程与工艺参数并进行了小型浮选闭路试验,分离出铜、硫、钨三种精矿产品,选矿指标良好,为在工业上实现该矿石的综合回收提供了依据。