Correlating π–π Stacking of Aromatic Diammoniums with Stability and Dimensional Reduction of Dion–Jacobson 2D Perovskites

Dion–Jacobson (DJ) phase 2D perovskites with various aromatic diammonium cations, potentially possessing high stability, have been developed for optoelectronics. However, their stability does not meet initial expectations, and some of them even easily degrade into lower-dimensional structures. Underlying the stability mechanism and dimensional reduction of these DJ 2D perovskites remains elusive. Herein, we report that π–π stacking intensity between aromatic cations determines structural stability and dimensional variation of DJ 2D perovskites by investigating nine benzene diammoniums (BDAs)-derived low-dimensional perovskites. The BDAs without intermolecular π–π stacking form stable DJ 2D perovskites, while those showing strong π–π stacking tend to generate 1D and 0D architectures. Furthermore, the π–π stacking intensity highly relies on molecular symmetry and electrostatic potential of BDAs; namely, asymmetry and small dipole moment facilitate alleviating the π–π stacking, leading to the formation of DJ 2D perovskites and vice versa. Our findings establish the relationship of aromatic diammonium structure−π–π stacking interaction–perovskite dimensionality, which can guide the design of stable DJ 2D perovskites and the manipulation of perovskite dimensionality for various optoelectronic applications

Correlating π–π Stacking of Aromatic Diammoniums with Stability and Dimensional Reduction of Dion–Jacobson 2D Perovskites

Dion–Jacobson (DJ) phase 2D perovskites with various aromatic diammonium cations, potentially possessing high stability, have been developed for optoelectronics. However, their stability does not meet initial expectations, and some of them even easily degrade into lower-dimensional structures. Underlying the stability mechanism and dimensional reduction of these DJ 2D perovskites remains elusive. Herein, we report that π–π stacking intensity between aromatic cations determines structural stability and dimensional variation of DJ 2D perovskites by investigating nine benzene diammoniums (BDAs)-derived low-dimensional perovskites. The BDAs without intermolecular π–π stacking form stable DJ 2D perovskites, while those showing strong π–π stacking tend to generate 1D and 0D architectures. Furthermore, the π–π stacking intensity highly relies on molecular symmetry and electrostatic potential of BDAs; namely, asymmetry and small dipole moment facilitate alleviating the π–π stacking, leading to the formation of DJ 2D perovskites and vice versa. Our findings establish the relationship of aromatic diammonium structure−π–π stacking interaction–perovskite dimensionality, which can guide the design of stable DJ 2D perovskites and the manipulation of perovskite dimensionality for various optoelectronic applications

Coupling P Nanostructures with P‑Doped g‑C₃N₄ As Efficient Visible Light Photocatalysts for H₂ Evolution and RhB Degradation

Fabricating heterostructures to promote the charge separation and doping heteroatom to modulate the band gap of the photocatalysts have been regarded as effective strategies to improve the photocatalytic performance. However, it is still an unresolved issue of doping element and fabricating heterostructures with good contact at the same time. In this study, P nanostructures/P doped graphitic carbon nitride composites (P@P-<i>g</i>-C₃N₄) were successfully composited by a solid reaction route. Various structural characterizations, including X-ray adsorption near edge structure, indicate that P has been doped into g-C₃N₄ and P nanostructures were directly grown on g-C₃N₄ to form heterostructures. As expected, the intimate contacted heterostructured composites exhibit much enhanced light absorption and high-efficiency transfer and separation of photogenerated electron–hole pairs, and consequently, the composites also possess the superior photocatalytic performance in the rapidly degrading RhB and an efficient H₂ production rate of 941.80 μmolh^–1g^–1. Systematical studies combining experimental measurements with theoretical calculations were carried out to expound the underlying reasons behind the distinct performance. This study pave a one-step way to synthesize earth abundant element C, N, and P as novel photocatalysts for photochemical applications