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Low-dimensional organic–inorganic hybrid halides, as an important branch of metal halide materials, have attracted much attention due to their excellent photoelectric properties. Herein, we designed one new hybrid cadmium chloride [C5H14NO]CdCl3 based on combinations of the d10 metal cation (Cd2+) and choline chloride molecules. [C5H14NO]CdCl3 single crystals belong to the orthorhombic Pna21 space group and show a one-dimensional (1D) structure with distorted [CdCl5O]5− octahedra. The second harmonic generation (SHG) response of [C5H14NO]CdCl3 exhibits an intensity of approximately 0.4 × KDP. Moreover, the photoluminescence properties of the [C5H14NO]CdCl3 crystal are activated by doping with Sn2+ ions having stereochemically active lone pair 5s2 electrons. Under UV excitation conditions, bright greenish-yellow light emission can be observed, and the quantum efficiency (PLQY) is as high as 91.27%. The luminescence mechanism is revealed by combining the results of temperature dependent luminescence and density functional theory (DFT) calculation. This work can serve as a guide for the design and synthesis of emerging optical materials. [ABSTRACT FROM AUTHOR]

Low-dimensional organic–inorganic metal halides have shown great application potential and new opportunities for use in solid-state lighting due to their excellent optical and electronic properties. However, the most studied hybrid compounds contain lead, which limits their application environments. The preparation of organic–inorganic metal halides with high luminous efficiency, long-term stability, and a lead-free composition for environmental protection has become an important goal for the design of materials. Here, novel Sb3+-doped indium-based metal halides, (CH3NH3)4InCl6·Cl, have been designed and synthesized via a simple mechanical ball milling method; in the lead-free zero-dimensional (0D) halide (CH3NH3)4InCl6·Cl, isolated [InCl6]3− octahedra are separated by methylamine cations. Under UV excitation, the bulk-phase powder exhibits broadband orange-yellow emission peaking at 607 nm with a full width at half-maximum of ∼160 nm upon incorporating Sb3+ into the (CH3NH3)4InCl6·Cl matrix. The photoluminescence quantum yield (PLQY) of Sb3+-doped (CH3NH3)4InCl6·Cl is as high as 67.72%. The effects of the Sb3+-doping concentration on the crystal structure and optical characteristic have been investigated. The indirect band gap characteristics of (CH3NH3)4InCl6·Cl were demonstrated via density functional theory (DFT) calculations, and the relatively wide band gaps of 3.83 eV and 2.99 eV of (CH3NH3)4InCl6·Cl and (CH3NH3)4ClInCl6:Sb3+ were experimentally determined. These experimental results suggest that the as-prepared Sb3+-doped (CH3NH3)4InCl6·Cl has potential applications in solid-state lighting devices. [ABSTRACT FROM AUTHOR]

An indium and phosphorus co-doped g-C3N4 photocatalyst (In,P-g-C3N4) was prepared by K2HPO4 post-treatment of an indium-doped g-C3N4 photocatalyst (In-g-C3N4) derived from in situ copolymerization of dicyandiamide and indium chloride. The experimental results and theoretical simulations revealed that the doped indium ions were located between the planes of g-C3N4 and phosphorus atoms were introduced into the g-C3N4 plane by replacing the carbon atoms, which existed in the form of P＝N bonds. The co-doping of indium and phosphorus with g-C3N4 not only extended its response to the visible light region but also synergistically promoted the separation and migration of photogenerated charge carriers. As a result, the In,P-g-C3N4 photocatalyst exhibited a hydrogen evolution rate as high as 4.03 mmol h−1 g−1, ca. 50 times that of pristine g-C3N4 (0.08 mmol h−1 g−1). [ABSTRACT FROM AUTHOR]

A novel copper and carbon co-modified TiO2 photocatalyst (TiO2–Cu/C) was prepared using a simple sol–gel method. The properties of the photocatalysts were investigated by XRD, Raman, BET, HRTEM, EDAX, XPS, absorption spectroscopy and PL techniques. It was revealed that copper was present as –O–Cu–O– species and carbon existed as elementary substance carbon nanoparticles on the surface of TiO2. Based on the experimental results, the band structure and electronic density of states of TiO2, TiO2–Cu and elementary substance carbon are predicted by theoretical calculations. The energy levels of the –O–Cu–O– species and the carbon nanoparticles were located above the valence band, which extends the absorption into the visible light region, facilitate the separation of photogenerated charge carriers and provide hole reactive sites on the surface. Thus, the photocatalytic activity of TiO2–Cu/C is much higher than that of pure TiO2, TiO2/C and TiO2–Cu for photoreduction of CO2 and H2O into CH4 under UV-light irradiation. [ABSTRACT FROM AUTHOR]