Gold nanoparticles confined into the walls of periodic mesoporous organosilicas (PMOs) with controllable morphology have been successfully fabricated through a one-pot method by using different CO₂ pressures. The synthesis can be easily conducted in a mixed aqueous solution by using HAuCl₄ as gold source and bis[3-(triethoxysilyl)propyl] tetrasulfide and tetramethoxysilane as the organosilica precursor. P123 and compressed CO₂ served as the template and catalytic/regulative agent, respectively. Transmission electron microscopy, N₂ adsorption, and X-ray diffraction were employed to characterize the structure of the obtained composite materials. To further investigate the formation mechanism, a series of ordered PMOs with one-dimensional nanotube, two-dimensional hexagonal, vesicle-like, and cellular foam structures were obtained by using different CO₂ pressures without the gold source. The mechanism for mesostructure evolution of PMOs with different CO₂ pressures was proposed and discussed in detail. The catalytic performance of Au-based PMOs was evaluated for the reduction of 4-nitrophenol (4-NP). These obtained composites with different mesostructures not only exhibit excellent catalytic activity, high conversion rate, and remarkable thermal stability, but they also exhibit morphology-dependent reaction properties in the reduction of 4-NP. The possible reaction pathway of the reactants to embedded Au active sites was proposed and schemed.

中文翻译：

---

通过压缩CO _2可控制介孔结构的金/周期性介孔有机硅

已通过使用不同的CO ₂压力通过一锅法成功地将金纳米颗粒限制在具有可控形态的周期性介孔有机硅（PMO）的壁中。通过使用HAuCl ₄作为金源和双[3-（三乙氧基甲硅烷基）丙基]四硫化物和四甲氧基硅烷作为有机二氧化硅前体，可以在混合水溶液中轻松进行合成。P123和压缩的CO _2分别用作模板和催化/调节剂。透射电子显微镜，N ₂吸附和X射线衍射被用来表征所获得的复合材料的结构。为了进一步研究其形成机理，在不使用金源的情况下，通过使用不同的CO ₂压力，获得了一系列具有一维纳米管，二维六边形，囊状和多孔泡沫结构的有序PMO 。不同CO _2的PMO介孔结构演化机理压力已提出并进行了详细讨论。评价了基于Au的PMOs对4-硝基苯酚（4-NP）还原的催化性能。这些获得的具有不同介观结构的复合材料不仅表现出优异的催化活性，高转化率和出色的热稳定性，而且在还原4-NP时还表现出形态学依赖性的反应特性。提出并设计了反应物与包埋的金活性位点可能的反应途径。