Ultra‐Sensitive, Selective and Repeatable Fluorescence Sensor for Methanol Based on a Highly Emissive 0D Hybrid Lead‐Free Perovskite

Abstract

A convenient and rapid detection method for methanol in ethanol remains a major challenge due to their indistinguishable physical properties. Herein, a novel fluorescence probe based on perovskite was successfully designed to overcome this bottleneck. We report a new zero‐dimensional (0D) hybrid perovskite of [MP]2InxSb1−xCl7 ⋅ 6 H2O (MP=2‐methylpiperazine) displaying an unusual green light emission with near‐unity photoluminescence quantum yield. Remarkably, this 0D perovskite exhibits reversible methanol‐response luminescence switching between green and yellow color but fail in any other organic vapors. Even for blended alcohol solutions, the luminescent probe exhibits excellent sensing performance with multiple superiorities of rapid response time (30 s) and ultra‐low detection limit (40 ppm), etc. Therefore, this 0D perovskite can be utilized as a perfect fluorescence probe to detect traces of methanol from ethanol with ultrahigh sensitivity, selectivity and repeatability. To the best of our knowledge, this work represents the first perovskite as fluorescence probe for methanol with wide potential in environmental monitoring and methanol detection, etc.

White Light Emission from Single-Component Cs7Cd3Br13:Pb2+,Mn2+ Crystals with High Quantum Efficiency and Enhanced Thermodynamic Stability

“…This implies that the Mn 2+ doping improves the thermodynamic stability of Cs 7 Cd 3 Br 13 significantly, which agrees well with the above theoretical calculation. Moreover, the FWHM of both emission bands becomes slightly larger, and the blue STE2 emission band presents a significant red shift as the temperature increases, which is ascribed to the enhanced electron–phonon interaction caused by the strong lattice distortion at elevated temperatures. − In contrast, the orange emission band composed of STE1 from Cs 7 Cd 3 Br 13 and Mn 2+ (d–d) transition exhibits a slight blue shift with the temperature increasing. To shed light on the substantial mechanism responsible for this phenomenon, the temperature-dependent PL spectra of Cs 7 Cd 3 Br 13 and Cs 7 Cd 3 Br 13 :12%Mn 2+ are measured separately.…”

Thermally Induced Reversible Fluorescence Switching of Lead Chloride Hybrids for Anticounterfeiting and Encryption

“…In addition, the degree of the deformation of a single [Pb−Cl 6 ] octahedron can be quantitatively assessed with the following equations for the octahedral angular variance σ 2 and distortion parameter Δ d When subjected to thermal stimulation, the (TPA)PbCl 3 -Green and (TPA)PbCl 3 -Blue octahedral structure of the ground state undergoes varying degrees of deformation, which may result in the structure of the excited states being somewhat different, giving them varied Stokes shifts. 10 To further determine the origin of emission, temperature-dependent PL spectra of (TPA)PbCl 3 -Green are recorded (Figure S13). With increasing temperature, the PL peak position shows minor redshifts accompanied by gradually increasing fluorescence intensity, which has been reported in (TPA) 2 PbBr 4 .…”

“…The larger values of Δ d and σ 2 normally represent greater degrees of octahedral distortion. When subjected to thermal stimulation, the (TPA)­PbCl 3 -Green and (TPA)­PbCl 3 -Blue octahedral structure of the ground state undergoes varying degrees of deformation, which may result in the structure of the excited states being somewhat different, giving them varied Stokes shifts . To further determine the origin of emission, temperature-dependent PL spectra of (TPA)­PbCl 3 -Green are recorded (Figure S13).…”

“…Recently, luminescence-based anticounterfeiting technology has been widely utilized on banknotes and luxury goods and is gradually replacing traditional anticounterfeiting measures, such as barcodes, thanks to their simplicity of operation and ease of industrial production. Stimuli-responsive luminescent materials belong to a category of molecular systems with intelligent behavior that can reversibly adjust the color or intensity of fluorescence by sensing external environmental stimuli such as light, , heat, , moisture, , mechanical forces, , and polar solvents , to enable anticounterfeiting and encryption functions. To date, a broad range of materials has been developed for anticounterfeiting and encryption applications, including doped inorganic semiconductor phosphors, − organic molecules, , and carbon dots, , which rely on tunable excitation wavelengths, afterglow, and aggregation bursts to change the fluorescent emission color.…”

Reversible Luminescent Switching Induced by Heat/Water Treatment in a Zero-Dimensional Hybrid Antimony(Ⅲ) Chloride

“…In addition, 0-D IOMHs may own soft lattice and strong electron–phonon coupling, thus leading to interesting photoluminescent properties, including broad emission and large Stokes shift [ 10 ]. As a result, the applications of photoluminescent 0-D IOMHs have flourished in light-emitting diode [ 11 , 12 , 13 , 14 , 15 ], X-ray scintillator [ 16 , 17 , 18 ], remote thermography [ 19 , 20 ], optical waveguide [ 21 ], anti-counterfeiting [ 22 , 23 , 24 , 25 , 26 ], as well as sensor [ 27 , 28 , 29 , 30 ].…”