【无机化学学报】doi: 10.11862/CJIC.20240057
In this study, parallelogram-like macrocyclic supramolecular metallacycles [Pd6(bpy)6(L1)4](PF6)8 (1a) and [Pd6(bpy)6(L2)4](PF6)8 (2a), where HL1=1-(1H-pyrazole-4-yl)-4-(4-pyridyl)benzene, HL2=9-(1H-pyrazole-4-yl)-10-(4-pyridyl)anthracene, and bpy=2, 2'-bipyridine, are synthesized by reacting aryl pyrazole pyridine ligands with dipalla-dium corners in aqueous solutions via metal-directed hierarchical self-assembly. The structures of the supramolecular Pd parallelograms are confirmed through single-crystal X-ray diffraction. Notably, the two parallelogram metallacycles can be used as"turn-on"fluorescence sensors to detect HSO3- through a disassembly mechanism. In addition, the 1a-based sensor shows selective detection of HSO3- without interference from other anions. The detection limit was as low as 0.131 μmol·L-1. Furthermore, complex 1a presented the semiquantitative visual detection ability for HSO3- in the test trip mode via fluorescence changes.
【无机化学学报】doi: 10.11862/CJIC.20240280
以生物质橙子皮为原料,通过简单的一步水热法制备了橙子皮基碳量子点(orange peel-based carbon quantum dots,OP-CQDs),并用荧光分析法对其性质进行了研究。结果表明,OP-CQDs水溶性好、荧光强、在生理pH范围内性能稳定。OP-CQDs对铁离子(Fe3+)有特异性猝灭反应且灵敏度高,同时,L-抗坏血酸(L-ascorbic acid,L-AA)能够使OP-CQDs-Fe3+体系的荧光部分恢复,形成了“开-关-开”的荧光检测体系。Fe3+和L-AA的检出限分别为1.1和31.8 μmol·L-1。
【物理化学学报】doi: 10.3866/PKU.WHXB202408005
化石燃料的消耗导致CO2排放量大幅增加,对环境构成严重威胁。本文探讨了石墨相氮化碳(g-C3N4)在光催化CO2还原中的潜在应用,以此来应对全球变暖的影响。然而,g-C3N4在这一过程中的有效性受到几个因素的限制,例如光生载流子的快速重组、可见光吸收能力差以及缺乏活性位点等。为了解决这些问题,人们采用了各种改性策略,包括调整g-C3N4的形貌(如量子点、纳米棒、纳米管、纳米片、空心球等形貌),掺杂各种原子,以及与其他半导体形成异质结。本综述重点讨论S型异质结在提高g-C3N4光催化性能方面的作用。总之,尽管g-C3N4已显示出作为光催化剂用于还原CO2的潜力,但仍需进一步研究和创新,以克服其当前的局限性。
【无机化学学报】doi: 10.11862/CJIC.20240086
制备了Ag负载于质子化g-C3N4(pCN)的纳米棒材料(Ag/pCN),对比了g-C3N4(CN)、表面负载Ag的CN(Ag/CN)、pCN和Ag/pCN在可见光条件下光催化降解亚甲蓝(MB)溶液的效果。结果表明,Ag/pCN光催化效率最高(92.63%),并且具有良好的稳定性;通过光电流-时间(I-t)曲线、Nyquist曲线、Mott-Schokkty曲线和捕获实验探究了Ag/pCN光催化降解MB的机理:虽然pCN的π共轭体系较CN发生变化,但由于形成了纳米棒,其比表面积的增加以及Ag负载的协同效应致使Ag/pCN具有优异的光催化性能。光催化过程中羟基自由基(·OH)是起主要作用的活性物质,其由光生电子(e-)与表面吸附的O2反应产生以及光生空穴(h+)与H2O或OH-反应产生。
【无机化学学报】doi: 10.11862/CJIC.20230477
采用原位溶剂热反应制备多级Ag/Bi/Nv-g-C3N4(氮空位-g-C3N4)/Ti3C2Tx肖特基结,并对其物相组成和晶体结构、微观形貌和孔结构、表面元素组成和化学态、光学和光电化学性质进行了表征。由于Ag、Bi和Ti3C2Tx协同的表面等离激元共振效应,Ag/Bi/Nv-g-C3N4/Ti3C2Tx表现出全光谱吸收特性。由载流子浓度差驱动的界面极化电荷转移诱导形成的肖特基结,显著提高了光生载流子(包括热电子和热空穴)的分离效率和利用率。因此,与Nv-g-C3N4、Ti3C2Tx、Ag/Nv-g-C3N4、Bi/Nv-g-C3N4和Ag/Bi/Nv-g-C3N4相比,Ag/Bi/Nv-g-C3N4/Ti3C2Tx表现出显著增强的全光谱催化活性,其在可见光和近红外光照射下光催化降解四环素的反应速率常数分别为0.033和0.008 6 min-1,为对比样品的10~2.1倍和8.6~1.8倍。
【无机化学学报】doi: 10.11862/CJIC.20230482
The adsorption behaviors of intrinsic graphene-like GaN (g-GaN) and transition metal (TM) atom-doped g-GaN on Cl2 and CO gas molecules were systematically investigated using first-principles calculations based on density functional theory. The results show that the adsorption of both Cl2 and CO on the intrinsic g-GaN was physisorbed, and since the adsorption energies of both systems were positive, it indicates that the systems are unstable. On the contrary, the adsorption energies of Cl2 and CO upon adsorption on Fe- and Co-doped g-GaN were negative and small, and the adsorption system is stable. By analyzing the properties of the density of states, charge density difference, and energy band structure, it can be concluded that the introduction of transition metal atoms can effectively enhance the interaction between gas molecules and g-GaN.
【物理化学学报】doi: 10.3866/PKU.WHXB202408002
通过半导体光催化将CO2转化为可储存的太阳能燃料是解决温室效应和资源短缺问题的有效策略。然而,光生载流子的快速复合严重限制了单组分催化剂的CO2还原能力。合成具有缺陷的S型异质结可以有效地分离光生电子和空穴,增强对非极性分子的吸附和活化。本文采用原位合成的方法构建了具有缺陷的S型ZnWO4/g-C3N4异质结。结果表明,CO2还原产生CO的速率高达232.4 μmol∙g-1∙h-1,选择性接近100%,分别是原始ZnWO4和g-C3N4的11.6倍和8.5倍。原位XPS和功函数分析证明了S型电荷转移路径。S型异质结实现了电子-空穴的有效空间分离,促进了CO2的还原。原位ESR表明CO2分子被氮空位吸附,氮空位是光催化反应中的电子受体,有利于电子捕获和分离。S型电荷转移模式和氮空位共同促进了CO2高效还原。这项工作为了解S型电荷转移机理和缺陷在调节CO2还原活性方面的协同作用提供了重要见解。
【无机化学学报】doi: 10.11862/CJIC.20240259
首先采用柠檬酸辅助溶胶-凝胶法制备钴酸镧(LaCoO3,LCO),并利用水热法制备LaCoO3/g-C3N4(LCO/CN)p-n型异质结复合光催化剂。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、紫外可见漫反射光谱(UV-Vis DRS)和光致发光(PL)光谱对LCO/CN进行了表征,评价了其对盐酸四环素(TC)的光催化降解性能,同时使用自由基捕获剂验证了光催化反应中起作用的活性基团,并推测了反应机理。结果表明,LCO和CN的复合显著增强了CN的光催化活性,当二者质量比为10%时制备的10%LCO/CN呈现出最佳的光催化性能,在120 min内对10 mg·L-1 TC的降解率高达96.2%,反应速率常数达到0.018 93 min-1,分别是CN和LCO的3.04倍和1.93倍。3次循环回收实验结果显示,10%LCO/CN对TC的降解率下降得较少,表明该催化剂具有良好的稳定性和实用性。
【无机化学学报】doi: 10.11862/CJIC.20240148
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.
【大学化学】doi: 10.12461/PKU.DXHX202405147
仪器分析实验“分子荧光法测定罗丹明B的含量”存在实验过于简单、未考虑实际情况等问题。因此,本改进实验在三维荧光扫描模式下获取样本数据,不进行复杂预处理,而是运用化学计量学算法解析出目标分析物的纯信号,进而实现了染色辣椒中罗丹明6G和123的同时测定。本改进实验提高了学生全面考虑问题和创新解决问题的能力。