学术界在表述环加成反应时，(m + n + …)和[m + n + …]环加成混用，不利于准确的学术交流。本文介绍了国际纯粹与应用化学联合会(IUPAC)规定的两种环加成反应表述方式，指明了它们的准确含义和使用环境。

通过对量子态空间、基函数、幺正变换等量子力学基本概念的介绍，阐释了原子结构中z轴表现出特殊性的原因，明确了在球对称的原子结构中，任何方向都不具有特殊性，z轴表观的特殊性主要源自人们选择了特定基函数来描述原子中电子的运动行为。

通过水热法制备出一系列Z型异质结Cu₂O/Bi₂MoO₆新型光催化剂。采用扫描电子显微镜、粉末X射线衍射、红外光谱、紫外可见吸收光谱等表征手段研究了催化剂的形貌、结构性质和光电化学性质，并以四环素(TC)为降解目标污染物，进一步探究了其催化效率。实验结果表明，Cu₂O的加入提高了复合催化剂的光催化性能，其中20% Cu₂O/Bi₂MoO₆复合催化剂(Cu₂O和Bi₂MoO₆的质量比为20%)降解效果最好，100 min内可降解95%的TC。Cu₂O与Bi₂MoO₆之间的协同作用使其可以吸收更多的可见光，所构建的Z型异质结改变了电子转移途径，提高了电子与空穴的分离效率，光催化活性显著提高。通过自由基捕获实验和能带结构，分析了Z型异质结Cu₂O/Bi₂MoO₆复合催化剂光催化降解TC可能的机理。

通过原位共沉淀法可控制备了系列直接Z型MIL-100(Fe)/BiOBr异质结。使用粉末X射线衍射(PXRD)、傅里叶红外变换(FTIR)光谱、紫外可见漫反射光谱(UV-Vis DRS)、扫描电镜(SEM)、高倍透射电镜(HRTEM)以及X射线光电子能谱(XPS)对MIL-100(Fe)/BiOBr异质结晶体结构、微观形貌、光学性能、化学组成进行表征。以低功率发光二级管可见光为光源，探究了MIL-100(Fe)/BiOBr异质结光芬顿降解磺胺甲恶唑(SMX)性能。最佳反应体系MB-7/Vis/H₂O₂(MB-7是MIL-100(Fe)质量为BiOBr质量的70%时制备的样品)在光源照射70 min后可降解99.8% SMX(5 mg·L^-1)。同时，还考察了H₂O₂浓度、催化剂投加量、pH值以及无机阴离子对MB-7/Vis/H₂O₂降解SMX影响。MB-7/Vis/H₂O₂能够在经过5轮循环降解实验后保持95%以上的SMX降解效率，表明其具有较好的循环稳定性。通过光致发光(PL)光谱、光电化学测试、活性物质捕获实验以及电子自旋共振(ESR)技术对光芬顿降解SMX机理进行了揭示。增强的光芬顿活性的机制主要来自于异质结的构建加速了光生载流子的分离，进而促进了活性物质产生以及Fe³⁺/Fe²⁺的循环。

利用简单的化学还原沉积法将Cu₂O纳米球和Ag纳米颗粒均匀包裹在十面体BiVO₄表面，成功构建了一种具有高效电荷载流子分离/转移特性的Z型异质结光催化剂Ag-Cu₂O/BiVO₄。Ag-Cu₂O/BiVO₄在可见光下光催化CO₂还原为CO的产率可达5.37 μmol·g^-1·h^-1，分别是纯BiVO₄和Cu₂O的35.8倍和6.25倍。通过X射线粉末衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、X射线能谱(EDS)、紫外可见漫反射光谱(UV-Vis DRS)、光致发光(PL)光谱、瞬态光电流响应(TPC)和电化学阻抗谱(EIS)对Ag-Cu₂O/BiVO₄的晶体结构、形貌、组成、能带结构和吸光能力等进行了系统表征分析，并提出了其光催化体系还原CO₂的催化机理。

The Z-scheme heterojunction Cu₂O/Bi₂CrO₆ photocatalyst was successfully prepared by introducing Cu₂O on the Bi₂CrO₆ surface using a coprecipitation method. The photocatalytic degradation of tetracycline (TC) on Cu₂O/Bi₂CrO₆ under visible light irradiation was investigated. It was found that the Cu₂O/Bi₂CrO₆ photocatalyst had the best photocatalytic activity when the mass ratio of Cu₂O to Bi₂CrO₆ was 20%, and the TC could be degraded by 87.5% within 100 min, which was about 1.8 times and 1.3 times higher than that of pure Bi₂CrO₆ and pure Cu₂O, respectively. Besides, the Cu₂O/Bi₂CrO₆ photocatalyst also showed good stability and reusability. The Z scheme heterojunction structure of Cu₂O/Bi₂CrO₆ provided increased active sites, enhanced interfacial charge separation, and improved separation efficiency of photogenerated electro-hole (e^--h⁺) pairs, leading to enhanced photocatalytic properties. Electron paramagnetic resonance (EPR) measurement confirmed that the superoxide radical (·O₂^-), hydroxyl radical (·OH), and h⁺ were the primary active species during photocatalysis.

MoS₂/Ag/g-C₃N₄ composite photocatalysts were prepared via hydrothermal synthesis, and a series of analytical methods were employed for systematic characterization. The results indicate that the significant enhancement in catalytic degradation activity is attributed to the formation of Z-scheme heterojunction, which effectively facilitates the transport and separation of photogenerated charge carriers while suppressing the recombination of photogenerated electron and hole pairs. Degradation experiments demonstrated that the prepared composite material achieved a degradation rate of up to 98% for rhodamine B (RhB) within 120 min, exhibiting superior photocatalytic performance compared to individual photocatalysts. Furthermore, capture experiments and electron paramagnetic resonance (EPR) results revealed that superoxide radicals (·O₂^-) and photogenerated holes (h⁺) were the key active species in the photocatalytic degradation of RhB. Finally, an in-depth discussion of the photocatalytic degradation mechanism of the composite material was conducted.

采用剥离-重组法，以剥离的CoAl层状双金属氢氧化物(CoAl-LDH)纳米片为主体，β-Bi₂O₃纳米胶粒为客体, 成功制备了β-Bi₂O₃柱撑CoAl-LDH复合材料(β-Bi₂O₃/CoAl-LDH)。运用X射线衍射、透射电子显微镜、紫外可见吸收光谱和X射线光电子能谱等方法表征了材料的形貌、结构和光电化学特性。制备的β-Bi₂O₃/CoAl-LDH柱撑材料具有2.1 nm的层间通道、62 m²·g^-1的比表面积和良好的可见光响应能力。在可见光辐照下，以四环素(TC)为模型污染物，考察材料光催化降解率。结果表明，β-Bi₂O₃/CoAl-LDH催化剂在90 min内可降解91.3%的TC，降解率远高于非柱撑的β-Bi₂O₃和CoAl-LDH。自由基捕获实验表明，超氧自由基(·O₂^-)和羟基自由基(·OH)是光催化体系主要的活性自由基。柱撑复合的β-Bi₂O₃与CoAl-LDH之间的电子耦合作用构建了Z型异质结，提高了光生电子与空穴对的分离率，赋予了材料良好的光催化性能。