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A simple method for facile synthesis of three-dimensional (3D) bismuth oxyhalide (BiOX, X═Cl, Br, I) hierarchical structures at room temperature has been developed. Under the influence of L-lysine surfactant, the bismuth and halogen (Cl, Br, I) sources hydrolyze and self-assemble into flower-like hierarchical architectures within 10 min. The resulted materials were characterized by XRD, FESEM, TEM, UV-vis DRS, and N2 adsorption-desorption techniques. We found that l-lysine is indispensable for their formation and the amount of HX has great effect on the final morphology. The BiOX (X═Cl, Br, I) hierarchical architectures are composed of single-crystalline nanoplates. We propose an amino-and-carboxyl structure-directing mechanism for the formation of the hierarchical structures. To evaluate the photocatalytic activity of the as-prepared materials, rhodamine-B was employed as a probe dye for degradation under visible light. All of the BiOX (X═Cl, Br, I) with 3D architectures show higher photocatalytic activities than their sheet-like counterparts. The superior activity is ascribed to the better light-harvesting capacity of the 3D hierarchical structures. The adopted method can be applied for large-scale generation of novel structures of similar kinds in a facile manner.

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The bubble point of reservoir petroleum fluids in nanoporous media is an important parameter in shale oil production. We present experimental results on the bubble points of octane and decane confined in controlled‐pore glasses (CPGs) with pore sizes of 4.3 and 38.1 nm. Differential scanning calorimetry (DSC) is used to measure the temperature at which the vapor phase begins to form (i.e., the bubble point). We find that the bubble point is dramatically affected by pore diameter: at 38.1 nm the confinement effect is insignificant, but at 4.3 nm two distinct bubble points appear, suggesting two distinct populations of evaporating fluid. Deviations are as great as ±15 K for both peaks relative to the bulk bubble point for 4.3 nm CPGs. Thermogravimetric analysis is consistent with DSC, supporting the validity of these results. Based on these experiments and previous simulations, we propose a two‐state model for the nanoconfined hydrocarbons. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1772–1780, 2016