Searching for a new family of modified CL-20 cage derivatives with high energy and low sensitivity

A new family of energetic caged compounds was designed by introducing -NH- into the CL-20 skeleton and their energetic properties and impact sensitivity were investigated by using density functional theory. The results indicate that favorable substitution positions of the amine groups in the skeleton is helpful for increasing the heats of formation. Most of the seven compounds have high crystal densities above 1.9 g/cm³. Five compounds have the predominant detonation properties over CL-20. The derivatives with one NH₂ group have lower impact sensitivity than those with two NH₂ groups. Taking the detonation performance and impact sensitivity into consideration, four compounds may be selected as the potential candidates of high energy density compounds.     

Self-supported metal sulphide nanocrystals-assembled nanosheets on carbon paper as efficient counter electrodes for quantum-dot-sensitized solar cells

Developing efficient counter electrodes (CEs) and quantum dots made of earth-abundant and non-toxic elements is essential but still challenging for quantum dot-sensitized solar cells (QDSSCs). Here, we report a facile strategy to prepare self-supported and robust CoS₂ and NiS nanocrystals-assembled nanosheets directly grown on carbon paper (MSx NS@CP) as efficient counter electrodes for QDSSCs. Such CEs integrate the merits of fast electron transfer from interconnected conductive scaffold, efficient mass transfer from hierarchically vertical nanosheet on 3D open substrate, as well as abundant highly active catalytic sites from metal sulphide nanocrystal units. As a result, QDDSCs based on such CoS₂ NS@CP and NiS NS@CP CEs achieve a PCE of 8.88% and 7.53%, respectively. The detailed analyses suggest that CoS₂ NS@CP has the highest catalytic activity and shows the lowest charger transfer resistance, leading to the highest PCE. These findings may inspire the design and exploration of other self-supported efficient CEs by integrating highly active catalysts onto 3D conductive networks for efficient QDSSCs.     

Salt‐Based Organic–Inorganic Nanocomposites: Towards A Stable Lithium Metal/Li10GeP2S12 Solid Electrolyte Interface

Solid‐state Li metal battery technology is attractive, owing to the high energy density, long lifespans, and better safety. A key obstacle in this technology is the unstable Li/solid‐state electrolyte (SSE) interface involving electrolyte reduction by Li. Herein we report a novel approach based on the use of a nanocomposite consisting of organic elastomeric salts (LiO‐(CH₂O)_n‐Li) and inorganic nanoparticle salts (LiF, ‐NSO₂‐Li, Li₂O), which serve as an interphase to protect Li₁₀GeP₂S₁₂ (LGPS), a highly conductive but reducible SSE. The nanocomposite is formed in situ on Li via the electrochemical decomposition of a liquid electrolyte, thus having excellent chemical and electrochemical stability, affinity for Li and LGPS, and limited interfacial resistance. XPS depth profiling and SEM show that the nanocomposite effectively restrained the reduction of LGPS. Stable Li electrodeposition over 3000 h and a 200 cycle life for a full cell were achieved.     

三嗪噁二唑基吡唑衍生物抑酶活性的QSAR模型

基于拓扑化学理论,原子类型电拓扑态指数(Mk)被用于表征18种三嗪噁二唑基吡唑衍生物的化学微环境。采用最佳变量子集回归方法,分别建立上述化合物对蛋白酪氨酸磷酸酯酶1B(PTP1B)、细胞分裂周期25磷酸酯酶B(Cdc25B)的抑酶活性(P_t、C_d)与Mk的定量构效关系(QSAR)模型。它们的最佳三元QSAR模型的判定系数(R~2)依次为0.896、0.828,逐一剔除法交叉验证相关系数(R_(cv)~2)依次为0.830、0.688。经R_(cv)~2、VIF、FT、AC等检验,该模型具有良好的稳健性及预测能力。经训练集验证,上述模型均具有良好的外部预测能力。模型显示,影响Pt、Cd的因素既有不同的结构基团(-CH_3、-O-、-NH_2和芳环中-N=),也有相同的因素(芳环中-C=)。     

A novel silane coupling agent with peroxy groups used as an initiator in the graft polymerization of AN or MMA on nano-TiO<Subscript>2</Subscript>

A novel peroxy group-containing silane coupling agent was synthesized and anchored on the surface of titanium dioxide nanoparticles (nano-TiO₂) to form an immobilized-initiator-modified nano-TiO₂ species. In this study, the kinetic parameters of the peroxy group-containing silane were tested and assessed using DSC. The pre-exponential factor (A_d) was 8.973?×?10⁸ and the activation energy (E_a) was 80.736 kJ mol^?1. Moreover, the empirical Arrhenius equation was determined to be ln K_d?=???80.736/RT?+?ln(8.973?×?10⁸). To obtain continuous polymers, acrylonitrile (AN) and methyl methacrylate (MMA) were polymerized using the novel peroxy group-containing silane and FeSO₄ as an initiator system. The number average molecular weights (M_n of PAN?=?3×10⁴ and M_n of PMMA?=?1.4?×?10⁵) and polydispersity indexes (PDI of PAN?=?2.76 and PDI of PMMA?=?1.65) were determined by GPC. It was suggested that the redox initiation system can generate highly reactive species on the surfaces of inorganic nanoparticles. The nano-TiO₂-grafted polymers were successfully obtained.     

Synthesis of new di-anchoring organic sensitizer based on quinoxaline acceptor for dye-sensitized solar cells

New quinoxaline-based organic sensitizer bearing di-anchoring group for dye-sensitized solar cells (DSSCs) was synthesized from diethyl 4,5-diaminophthaltate, in which was prepared under mild condition by using Takehito’s method. The synthesized sensitizer was compared with mono-anchoring sensitizer through absorption spectra, emission spectra, J-V curve, and IPCE spectra, indicating the di-anchoring group leads to a noticeable improvement of J_sc value owing to more efficient intramolecular charge transfer and channel number increment.     

Amorphous CoSnO3@rGO nanocomposite as an efficient cathode catalyst for long-life Li-O2 batteries

An amorphous CoSnO₃@rGO nanocomposite fabricated using a surfactant-assisted assembly method combined with thermal treatment served as a catalyst for non-aqueous lithium-oxygen (Li-O₂) batteries. In contrast to the specific surface area of the bare CoSnO₃ nanoboxes (104.3 m² g^–1), the specific surface area of the CoSnO₃@rGO nanocomposite increased to approximately 195.8 m² g^–1 and the electronic conductivity also improved. The increased specific surface area provided more space for the deposition of Li₂O₂, while the improved electronic conductivity accelerated the decomposition of Li₂O₂. Compared to bare CoSnO₃, the overpotential reduced by approximately 20 and 60 mV at current densities of 100 and 500 mA g^?1 when CoSnO₃@rGO was used as the catalyst. A Li-O₂ battery using a CoSnO₃@rGO nanocomposite as the cathode catalyst cycled indicated a superior cyclic stability of approximately 130 cycles at a current density of 200 mA g^–1 with a limited capacity of 1000 mAh g^–1, which is 25 cycles more than that of the bare amorphous CoSnO₃ nanoboxes.     

双矿化剂对合成ZSM-5分子筛酸性和织构特征及其甲醇转化制丙烯催化性能的影响

采用静态水热法在F^--OH^-体系中,以四丙基氢氧化铵为模板剂、偏铝酸钠为铝源、正硅酸乙酯为硅源,合成了纳米SiO₂-ZSM-5分子筛,考察了F^-/Al₂O₃物质的量比对所合成的ZSM-5分子筛织构性质和甲醇转化制丙烯催化性能的影响。结果发现,随着初始溶胶F^-/Al₂O₃物质的量比的增大,产物中SiO₂的含量增大,ZSM-5分子筛的相对结晶度有所降低;同时,分子筛的比表面积和孔容减小、酸强度降低、酸量减少。对于甲醇转化制丙烯,最佳F^-/Al₂O₃物质的量比为12;此时,丙烯选择性高于45%,丙烯/乙烯（P/E）比值大于10。反应机理分析表明,过渡态择形选择性是控制烯烃选择性的重要因素。