Highly efficient visible-light photocatalytic ethane oxidation into ethyl hydroperoxide as a radical reservoir

Photocatalytic ethane conversion into value-added chemicals is a great challenge especially under visible light irradiation. The production of ethyl hydroperoxide (CH₃CH₂OOH), which is a promising radical reservoir for regulating the oxidative stress in cells, is even more challenging due to its facile decomposition. Here, we demonstrated a design of a highly efficient visible-light-responsive photocatalyst, Au/WO₃, for ethane oxidation into CH₃CH₂OOH, achieving an impressive yield of 1887 μmol g_cat⁻¹ in two hours under visible light irradiation at room temperature for the first time. Furthermore, thermal energy was introduced into the photocatalytic system to increase the driving force for ethane oxidation, enhancing CH₃CH₂OOH production by six times to 11 233 μmol g_cat⁻¹ at 100 °C and achieving a significant apparent quantum efficiency of 17.9% at 450 nm. In addition, trapping active species and isotope-labeling reactants revealed the reaction pathway. These findings pave the way for scalable ethane conversion into CH₃CH₂OOH as a potential anticancer drug.

Highly efficient visible-light driven photocatalytic oxidation of ethane into ethyl hydroperoxide was realized for the first time over Au/WO₃.     

可降解自固化类骨磷灰石支架的研究

0引言一直以来,钙磷生物材料如羟基磷灰石(hy-droxyapatite,HA)由于其成份与骨的无机成份相似,具有良好的生物相容性,作为骨修复材料引起了人们广泛的兴趣。磷酸钙骨水泥是一类可在生理条件下自固化的非陶瓷型类HA人工骨材料,这种由磷酸钙骨水泥(calcium phosphate cement,CPC)转变而成的HA,与天然骨磷灰石有类似的组成结构,植入人体后可参与新陈代谢,促进骨组织生长[1,2]。一些研究显示,CPC具有成骨活性和生物降解性,在体内被吸收的同时可引导新骨的生成,从而可克服自体骨、磷酸三钙陶瓷因吸收降解过快造成的局部缺陷以及陶瓷型HA长…     

新型手性Salen双核锌配合物的分子识别研究

合成了新型手性Salen配体（H3L）及新型手性Salen双核锌配合物（主体）.通过研究主体对咪唑类客体及氨基酸酯类客体的分子识别行为,测定了这些配位反应的缔合常数.主体对咪唑类客体分子识别的缔合常数顺序为:K(Im) >K(2-MeIm) >K(2-Et-4-MeIm).主体对氨基酸酯类客体分子识别的缔合常数顺序为:K(LeuOCH3) >K(ValOCH3) >K(AlaOCH3) >K(SerOCH3),配位数均为2.主体与D、 L型氨基酸酯分子识别反应在不同温度下的缔合常数结果表明,随着温度的升高,对映选择性下降.实验发现反应体系中存在焓熵补偿关系. CD光谱的研究结果也反映了主体对不同客体识别能力的差异.     

Powering the analytical glow discharge

The glow discharge may be powered by direct current (dc), radio frequency (rf) and pulsed discharge sources. Each has specific advantages and special features that should be considered by analysts using the various forms of glow discharge spectroscopy. This paper reviews some of the factors that contribute to the selection of a power source for the glow discharge.     

手性3,5-二甲基-2-芳基-2-吗啉醇盐酸盐的合成及其晶体结构

以(S)-2-氨基丙醇为手性源与α-溴-3-氯苯丙酮反应, (R)-2-氨基丙醇为手性源与6-甲氧基-2-(2-溴丙酰基)萘反应, 分别合成了手性纯化合物(2R,3R,5S)-3,5-二甲基-2-(3-氯苯基)-2-吗啉醇盐酸盐(4a)和(2S,3S,5R)-3,5-二甲基-2-(6-甲氧基-2-萘基)-2-吗啉醇盐酸盐(4b), 利用X射线单晶衍射仪测定了两化合物的晶体结构和两化合物的空间结构, 并初步分析两化合物空间结构, 化合物4a晶体属正交晶系, 空间群为P2₁2₁2, 晶胞参数为: a＝0.8718(2) nm, b＝0.7883(2) nm, c＝2.0247(6) nm, Z＝4, V＝1.3915(7) nm³, D_c＝1.328 g/cm³, F(000)＝584, R₁＝0.0399, wR₂＝0.0797, S＝1.042. 化合物4b晶体属正交晶系, 空间群为P2₁2₁2₁, 晶胞参数为: a＝0.71035 (9) nm, b＝0.77703(10) nm, c＝2.9820(4) nm, Z＝4, V＝1.6318(4) nm³, D_c＝1.318 g/cm³, F(000)＝688, R₁＝0.0520, wR₂＝0.1108, S＝0.994.     

聚酰亚胺／聚N－乙烯吡咯烷酮分子复合物的合成和表征

由原位缩聚制备了刚性高分子聚酰亚胺（ＰＩ）和柔性基体聚Ｎ－乙烯吡咯烷附（ＰＶＰ）的分子复合物，并由实验证明了中间体聚酰胺酸（ＰＡ）和聚乙烯吡咯烷酮大分子之间存在的酸一碱相互作用．这种相互作用促进了混容性，使聚酰亚胺能以分子水平或接近分子水平分散在聚毗咯烷酮的基体之中．聚酰亚胺／聚Ｎ－乙烯吡咯烷团分子复合物的薄膜呈透明性，在整个组成范围内只有一个Ｔｇ，显示单相行为。当ＰＩ含量＜２０％时，ＳＥＭ相片呈现均相形貌，看不到ＰＩ微晶．广角Ｘ－ｒａｙ衍射图表明ＰＩ特征结晶峰消失，和无定形的ＰＶＰ完全混容．当ＰＩ含量＞４０％，ＳＥＭ显示有均匀分布的、棒状ＰＩ微晶存在．通过分子复合，即使ＰＩ含量为１０％，聚Ｎ－乙烯吡咯烷酮不再溶于乙醇，耐热性也有提高．     

LiNi0.8Co0.2O2 / MWNTs复合物超级电容器电极材料的研究

Multiwalled carbon nanotubes (MWNTs) were used as the conductive additive in the electrode materials. The electrochemical properties of supercapacitors based on LiNi_0.8Co_0.2O₂ / MWNTs composite and LiNi_0.8Co_0.2O₂/acetylene black composite and MWNTs in 1.0 mol·L^-1 LiClO₄ / EC+DEC [V(EC)∶V(DEC)=1∶1] electrolyte were investigated by means of constant charge/discharge current tests, respectively. The experimental results show that the LiNi_0.8Co_0.2O₂ / MWNTs composite has better performance than that of others, and the maximum specific capacitance of the supercapacitor can reach 271.6 F·g^-1, while the energy density is up to 339.5 Wh·kg^-1. Furthermore, it is remarkable that the performance of MWNTs is better than that of acetylene black as the conductive additive.     

Li—Ni—La—O系复合氧化物催化剂上甲烷氧化偶联的研究

考察了Ｌｉ－Ｎｉ－Ｌａ－Ｏ系催化剂的组成、结构及反应条件对甲烷氧化偶联反应活性的影响。在７８０℃、ＣＨ４：Ｏ２：Ｎ２＝２：１：７、空速１５０００ｈ＾－１时，Ｃ２烃收率可达２５．８％。ＸＲＤ、ＩＲ、ＸＰＳ及ＳＥＭ等的结构分析表明，在ＬｉＬａ１－ｘＮｉｘＯ２催化剂中，当０．１≤ｘ≤０．９时，该催化剂由ＬｉＮｉＯ２和Ｌａ２Ｎｉ１－ｙＬｉｙＯ４－λ两相组成，ｘ＜０．３时出现了ＬｉＬａＯ２相，Ｌａ２Ｎｉ１－     

热致液晶共聚酯对聚丙烯结晶的诱导作用

用差示扫描量热法和光学解偏振法研究了热致液晶性芳香共聚酯与聚丙烯共混物的等温和非多温结晶行为.结果表明,这一热致液晶聚合物对聚丙烯结晶有诱导成核和加速作用.当共聚酯含量在2-5％之间时,聚丙烯的结晶速率最快.偏光显微镜的观察揭示出在聚丙烯熔体中原位形成的液晶聚合物微纤诱导了聚丙烯横穿晶的形成.     

FFC-1离子交换纤维物理化学性能的研究

利用扫描电镜、热失重-红外、元素分析、低温氮吸附等技术和化学手段对聚羧酸基FFC-1离子交换纤维的结构与性能特点等进行了系统研究．结果表明：FFC-1离子交换纤维为含适量酰肼类交联键的聚羧酸(钠)型离子交换材料，外比表面积大和传质距离短是其反应动力学性能优异的主要原因，FFC-1纤维具有良好的化学与热稳定性。在5mol/L硫酸、硝酸、盐酸和2mol／L氢氧化钠溶液中浸泡，交换容量未见明显降低。但过氧化氢溶液对其功能基有明显破坏，CO2为FFC-1纤维在高温区间(300℃～350℃)的主要分解产物。