Recently, 2D organic–inorganic hybrid lead halide perovskites have attracted intensive attention in solid‐state luminescence fields such as single‐component white‐light emitters, and rational optimization of the photoluminescence (PL) performance through accurate structural‐design strategies is still significant. Herein, by carefully choosing homologous aliphatic amines as templates, isotypical perovskites [DMEDA]PbCl4 (1, DMEDA=N,N‐dimethylethylenediamine) and [DMPDA]PbCl4 (2, DMPDA=N,N‐dimethyl‐1,3‐diaminopropane) having tunable and stable broadband bluish white emission properties were rationally designed. The subtle regulation of organic cations leads to a higher degree of distortion of the 2D [PbCl4]2− layers and enhanced photoluminescence quantum efficiencies (<1 % for 1 and 4.9 % for 2). The broadband light emissions could be ascribed to self‐trapped excitons on the basis of structural characterization, time‐resolved PL, temperature‐dependent PL emission, and theoretical calculations. This work gives a new guidance to rationally optimize the PL properties of low‐dimensional halide perovskites and affords a platform to probe the structure–property relationship.

Visible light driven photocatalysts based on crystalline metal halides received much less attention compared with dense or composite oxide semiconductors due to low photochemical stabilities. Here, by using large conjugated organic cations as structural direction agents, a series of hybrid cuprous and/or lead halides have been solvothermally prepared and structurally characterized. Compounds H­[(Me)3-TPT]6(Cu2I6)3(Pb6I19)·(H2O)2 (1) and [(Me)3-TPT]2Cu2Pb3Br14 (2; TPT = 2,4,6-tri­(4-pyridyl)-1,3,5-triazine) contain uncommon Lindqvist-type [Pb6I19]7– nanoclusters and heterometallic [Cu2Pb3Br14]6– units, respectively. Compounds [H3TIB]2Pb5Br16 (3) and H­[(Me)3-TIB]2Pb5I17 (4; TIB = 1,3,5-tris­(1-imidazolyl)­benzene) are composed of one-dimensional (1D) [Pb5Br16]6– chains and two-dimensional (2D) [Pb5I17]7– layers, respectively. The photosensitized conjugated organic cations offer a great contribution to the conduction bands, which lead to narrow band gaps of 2.01–2.35 eV. Under visible light irradiation, compound 4 exhibits efficient and stable photocatalytic degradation activity for various organic pollutants. The possible photocatalytic mechanism obtained from the radical trapping experiments and electronic band structural calculation show that conjugated organic cations effectively inhibit the recombination of photoinduced electron–hole pairs leading to excellent photocatalytic activity and photochemical stability.

Abstract. Hexagonal CePO 4 nanorods were synthesized via a simple chemical precipitation route at room-temperature without the presence of surfactants and then characterized by powder X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectrometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible (UVvis) absorption and photoluminescence (PL) spectroscopy. Hexagonal CePO 4 nanorods exhibit strong ultraviolet absorption and ultraviolet luminescence, which correspond to the electronic transitions between 4f and 5d state of Ce 3+ ions.

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