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Zero-dimension (0D) lead-free metal halide perovskites have attracted great attention because of their outstanding photophysical properties. However, the development of tunable-color-temperature white-light emission in single perovskite phosphors is still a challenge. Herein, a dual-band tunable multicolor emitters based on ns2 ions (Bi3+ and Te4+) codoped with a 0D hybrid perovskite derivative (C4H12N)2HfCl6 is reported. The prepared (C4H12N)2HfCl6:Bi3+/Te4+ samples exhibit broad dual-band emission originating from the dopant self-trapped excitons of [BiCl6]3– and [TeCl6]2–, respectively. By virtue of the energy transfer from blue-emitting (Bi3+) to yellow-emitting (Te4+), tunable dual-emission white-light emission covering the entire visible region is achieved. Meanwhile, Bi3+/Te4+-codoped perovskites exhibit unique excitation-dependent emission, and a wide color gamut can be obtained by precisely controlling the excitation wavelength, which corresponds to the color hue evolution from warm white to blue, then to white, and finally to orange. These findings provide fundamental insight into multicolor emission in the Bi3+/Te4+-codoped systems and open up more opportunities for multifunctional applications. [ABSTRACT FROM AUTHOR]

Hybrid lead-free halide perovskites have attracted substantial attention because of their superior optical properties. However, it is difficult for most metal perovskite materials with a single dopant to achieve multimode excitation and tunable or full-spectrum emission, leading to rare applications in white-light-emitting diodes and smart anticounterfeiting. Herein, a series of Sb3+-doped organic–inorganic halide hybrid (TMA)2ZrCl6 (TMA = C4H12N) microcrystals with intriguing excitation-dependent luminescence is reported. The prepared (TMA)2ZrCl6:Sb3+ perovskites exhibited three emission groups under variable excitation, corresponding to intrinsic host self-trapped excitons, dopant-induced extrinsic free excitons, and self-trapped excitons. The multiexcitonic emission modes in (TMA)2ZrCl6:Sb3+ enabled dynamic color transfer by controlling the excitation wavelength. Tunable emission, high-efficiency luminescence (photoluminescence quantum yield up to 94.31%), and excellent environmental stability provide unique advantages in anticounterfeiting and solid-state lighting. The results offer fundamental insights into the color kinetics of antimony-doped hybrid metal halides, facilitating opportunities for multifunctional applications. [ABSTRACT FROM AUTHOR]

Chiral nanostructures or chiral arrangements of plasmonic nanoparticles can strongly interact with circularly polarized light, giving rise to chiroptical effects such as circular dichroism and optical rotation. In parallel, enhanced optical fields around metallic nanostructures have been shown to be capable of enhancement of both linear and nonlinear optical processes. Sum frequency generation (SFG) spectroscopy, a nonlinear process, has shown chiral transitions where s- and p-polarizations mix to generate so-called chiral SFG. Here we combine chiral plasmonic nanostructures with chiral SFG to explore chiral nonlinear optical responses. We use chiral gold hooks (chiral), which are compared to disks (achiral) in their ability to generate chiral SFG signals and enable chiral SFG transitions. The plasmonic characteristics of the nanostructures measured by SFG and calculated by finite-difference time-domain (FDTD) reveal multiple polarization-dependent plasmon modes. Here we show, for the first time, that chiral gold nanoparticles can generate chiral SF electronic resonances. This optical metasurface with chiral cells and its enhancement mechanism are expected to be applied in sensing and detection to chiral macromolecules or the signal processing in optical communications. [ABSTRACT FROM AUTHOR]

We present a method for synthesizing MoS2/Graphenehybridheterostructures with a growth template of graphene-covered Cu foil.Compared to other recent reports,(1, 2) a much lowergrowth temperature of 400 °C is required for this procedure.The chemical vapor deposition of MoS2on the graphene surfacegives rise to single crystalline hexagonal flakes with a typical lateralsize ranging from several hundred nanometers to several micrometers.The precursor (ammonium thiomolybdate) together with solvent was transportedto graphene surface by a carrier gas at room temperature, which wasthen followed by post annealing. At an elevated temperature, the precursorself-assembles to form MoS2flakes epitaxially on the graphenesurface via thermal decomposition. With higher amount of precursordelivered onto the graphene surface, a continuous MoS2filmon graphene can be obtained. This simple chemical vapor depositionmethod provides a unique approach for the synthesis of graphene heterostructuresand surface functionalization of graphene. The synthesized two-dimensionalMoS2/Graphene hybrids possess great potential toward thedevelopment of new optical and electronic devices as well as a widevariety of newly synthesizable compounds for catalysts. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) suffer from limited ion diffusion and structural expansion, generating the urgent demand for Na + accommodable materials with promising architectures. In this work, the rational exploration for Co 4 S 3 nanoparticles confined in an MnS nanorod-grafted N, S-codoped carbon polyhedron (Co-Mn-S@N-S-C) is achieved by the in situ growth of MOF on MnO 2 nanorod along with the subsequent carbonization and sulfurization. Benefiting from the distinctive nanostructure, the Co-Mn-S@N-S-C anode delivers excellent structural stability, resulting in prolonged cycling stability with a capacity retention of 90.2% after 1000 cycles at 2 A g -1 . Moreover, the reaction storage mechanism is clarified by the in situ X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements. The results indicate that properly designed electrode materials have huge potential applications for highly efficient energy storage devices.

Plastic recycling and reprocessing activities may release organophosphate ester (OPE) flame retardants and plasticizers into the surrounding environment. However, the relevant contamination profiles and impacts remain not well studied. This study investigated the occurrence of 28 OPEs and their metabolites (mOPEs) in rainfall runoffs and agricultural soils around one of the largest plastic recycling industrial parks in North China and identified novel organophosphorus compounds (NOPs) using high-resolution mass spectrometry-based nontarget analysis. Twenty and twenty-seven OPEs were detected in runoff water and soil samples, with total concentrations of 86.0-2491 ng/L and 2.53-199 ng/g dw, respectively. Thirteen NOPs were identified, of which eight were reported in the environment for the first time, including a chlorine-containing OPE, an organophosphorus heterocycle, a phosphite, three novel OPE metabolites, and two oligomers. Triphenylphosphine oxide and diphenylphosphinic acid occurred ubiquitously in runoffs and soils, with concentrations up to 390 ng/L and 40.2 ng/g dw, respectively. The downwind areas of the industrial park showed elevated levels of OPEs and NOPs. The contribution of hydroxylated mOPEs was higher in soils than in runoffs. These findings suggest that plastic recycling and reprocessing activities are significant sources of OPEs and NOPs and that biotransformation may further increase the ecological and human exposure risk.

Metal sulfide anodes have aroused much attention in potassium ion batteries (PIBs) owing to their high theoretical capacities, but the sluggish kinetics and inferior cycling performance caused by severe volumetric change and particle pulverization greatly hinder their further development. Herein, robust hollow structure design together with phase structure engineering endow (Bi-Sb) 2 S 3 @N-C anode with superior (de)potassiation kinetics and excellent electrochemical performances in PIBs. Specifically, in situ X-ray diffraction combined with density functional theory calculations and ex situ X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy (TEM) analyses indicated a fresh reaction mechanism of (Bi-Sb) 2 S 3 anode with a distinctive multistep (de)potassiation route along (003) plane of (Bi,Sb) alloy thanks to the Bi-Sb phase regulation in (Bi-Sb) 2 S 3 anode, ensuring it with superior reaction kinetics. Moreover, in situ TEM characterization revealed the advantages of the hollow nanostructure with carbon shell, facilitating fast ion transport kinetics and high tolerance of volume change as well as enabling the structural integrity of electrode material during (de)potassiation. As a result, the (Bi-Sb) 2 S 3 hollow nanocube with N-doped carbon shell ((Bi-Sb) 2 S 3 @N-C) delivers a high initial Coulombic efficiency of 66.3%, a great rate performance of 289 mAh g -1 at 2.0 A g -1 , and an ultralong cycling life (89% retention after 220 cycles at 0.1 A g -1 and 85% retention after 1600 cycles at 2.0 A g -1 ) in PIBs. Furthermore, the full cell of (Bi-Sb) 2 S 3 @N-C//PTCDA affords a high reversible capacity of 281 mA h g -1 at 1.0 A g -1 after 300 cycles. This work combines structural design and in situ techniques, proving a successful nanostructure engineering strategy to rationalize alloy-type electrode materials for PIBs.

(sp 2 )C-(sp 2 )C bond formation is one of the most utilitarian techniques in target synthesis and material and pharmaceutical production. Biaryls usually emerge with the coupling of aryl halides or pseudohalides and require the prepreparation of an organometallic reagent, which results in low efficiency and atomic economy. The classic Ullmann reactions could be adopted to directly synthesize biaryls from aromatic halides. However, the requirement of extremely high temperatures limits the usage of the methodology in manufacturing. At the same time, the mechanism triggers a wide debate between classic redox and redox reactions involving radicals. In this work, a bimetallic system was demonstrated, referring to stoichiometric copper powder in the presence of a catalytic amount of Pd(OAc) 2 , which contributed to delivering various symmetric/asymmetric (sp 2 )C-(sp 2 )C species. It has been proposed that the coupling process might be promoted via radicals produced by redox between Cu(0) and Pd(IV) species in the heating system. Increasing examples demonstrated the good tolerance of this method for aryl bromide among functional groups.

Sb 3+ -doped halide perovskites are promising candidates for solid-state lighting due to their diverse fluorescent colors and high efficiency. However, the mismatched high excitation energy with commercial UV chips is one of the critical issues to be addressed. Herein, a Bi 3+ codoping strategy was established as a general and efficient approach to modulate the excitation spectrum from the Sb 3+ -doping center in all-inorganic perovskites of Cs 2 InCl 5 ·H 2 O, Cs 2 NaInCl 6 , and Rb 3 InCl 6 . The incorporated Bi 3+ greatly enhanced the splitting of the A band ( 1 S 0 - 3 P 1 transition) and boosts the enormous redshift of the low-energy branch in all these systems. The interactions persist strongly even at extremely low doping concentrations, suggesting a dipole-based long-range interaction. The results provide an in-depth insight into the contribution mechanism of Bi 3+ to Sb 3+ in all-inorganic perovskites, which throws light upon tuning the excitation spectrum of broadband emission from the extrinsic self-trapped exciton (STE).

Sb 3+ doping confers highly efficient and color-diverse broadband light emission to all-inorganic metal-halide perovskites. However, the emission mechanism is still under debate. Herein, a trace amount of Sb 3+ ions (<0.1% atomic percentage) doping in the typical all-inorganic perovskites Cs 2 NaInCl 6 , Rb 3 InCl 6 , and Cs 2 InCl 5 ·H 2 O allows universal observation of the fine structure in the photoluminescence excitation spectrum of the ns 2 electron. A lifetime mapping method was utilized to reveal the origin of broadband emission triggered by Sb 3+ doping, by which various fluorescence components can be differentiated. In particular, free-exciton emission was identified at the high-energy end of the broadband emission for all three doped systems. The excitation-energy- and temperature-dependent fluorescence decay further indicates the existence and origin of self-trapped states. The observed structural and vibrational symmetry-dependent emission behaviors suggest dipole interactions can dramatically alter Stokes-shift energy and modulate the light-emitting wavelength.

Two-dimensional (2D) transition metal dichalcogenide (TMDC) monolayers have been widely used for optoelectronic devices because of their ultrasensitivity to light detection acquired from their direct gap properties. However, the small cross-section of photon absorption in the atomically thin layer thickness significantly limits the generation of photocarriers, restricting their performance. Here, we integrate monolayer WS 2 with 2D perovskites Cs 2 AgBiBr 6 , which serve as the light absorption layer, to greatly enhance the photosensitivity of WS 2 . The efficient charge transfer at the Cs 2 AgBiBr 6 /WS 2 heterojunction is evidenced by the shortened photoluminescence (PL) decay time of Cs 2 AgBiBr 6 . Scanning photocurrent microscopy of Cs 2 AgBiBr 6 /WS 2 /graphene reveals that improved charge extraction from graphene leads to an enhanced photoresponse. The 2D Cs 2 AgBiBr 6 /WS 2 /graphene vertical heterostructure photodetector exhibits a high detectivity ( D *) of 1.5 × 10 13 Jones with a fast response time of 52.3 μs/53.6 μs and an on/off ratio of 1.02 × 10 4 . It is worth noting that this 2D heterostructure photodetector can realize self-powered light detection behavior with an open-circuit voltage of ∼0.75 V. The results suggest that the 2D perovskites can effectively improve the TMDC layer-based photodetectors for low-power consumption photoelectrical applications.

Lead halide perovskites have shown great potential in photovoltaic and photocatalytic fields. However, the toxicity of lead impedes their wide application. Herein composites of lead-free halide perovskite Cs 2 AgBiBr 6 supported on nitrogen-doped carbon (N-C) materials were synthesized successfully through a facile one-pot method for the first time. Without deposition of noble metals as the cocatalyst, the optimal composite Cs 2 AgBiBr 6 /N-C (Cs 2 AgBiBr 6 /N-C-140) exhibits outstanding photocatalytic performance with a high hydrogen evolution rate of 380 μmol g -1 h -1 under visible light irradiation (λ ≥ 420 nm), which is about 19 times faster than that of pure Cs 2 AgBiBr 6 and 4 times faster than that of physically mixed Cs 2 AgBiBr 6 /N-C-140, respectively. The Cs 2 AgBiBr 6 /N-C-140 composite also displays high stability with no significant decrease after six cycles of repeated hydrogen evolution experiments. The addition of N-C with a high surface area helps to prevent aggregation of Cs 2 AgBiBr 6 NPs and provides more pathways for the migration of photoinduced carriers. The nitrogen dopant can facilitate photoinduced electron transfer from Cs 2 AgBiBr 6 to N-C to result in spatially separated electrons and holes with prolonged electron time and greatly enhance the photocatalytic performance. This study indicates that Cs 2 AgBiBr 6 -based perovskite materials are promising candidates for photocatalytic hydrogen evolution.

Fundamental understanding of the transport properties within nanoparticle composite electrolytes is necessary for the development of next-generation electrochemical devices. Herein, the effect of surface-modified silica nanoparticles with aminophenyl, amide, and sulfonate functional groups (AP-SiO 2 , AM-SiO 2 , and SU-SiO 2 ) on the ion transport properties of composite electrolytes is systematically investigated. The competition between surface repulsive and attractive interactions of nanoparticles is reflected in the nature of the morphology and particle network in electrolytes, further affecting the ionic conductivity of electrolytes and diffusion coefficient of ions. The obvious decrease is observed in the AP-SiO 2 -based system because of the severe agglomeration of nanoparticles. By contrast, the AM-SiO 2 and SU-SiO 2 form the regular particle network structure and accelerate the salt dissociation in electrolytes, thereby providing an effective ion transport pathway and more mobile ions for conduction, respectively. Consequently, the composite systems with AM-SiO 2 and SU-SiO 2 deliver remarkable enhancement in the ion transport properties.

Flexible manipulation of the carrier transport behaviors in two-dimensional materials determines their values of practical application in logic circuits. Here, we demonstrated the carrier-type manipulation in field-effect transistors (FETs) containing α-phase molybdenum ditelluride (MoTe 2 ) by a rapid thermal annealing (RTA) process in dry air for hole-dominated and electron-beam (EB) treatment for electron-dominated FETs. EB treatment induced a distinct shift of the transfer curve by around 135 V compared with that of the FET-processed RTA treatment, indicating that the carrier density of the EB-treated FET was enhanced by about 1 order of magnitude. X-ray photoelectron spectroscopy analysis revealed that the atomic ratio of Te decreased from 66.4 to 60.8% in the MoTe 2 channel after EB treatment. The Fermi level is pinned near the new energy level resulting from the Te vacancies produced by the EB process, leading to the electron-dominant effect of the MoTe 2 FET. The electron-dominated MoTe 2 FET showed excellent stability for more than 700 days. Thus, we not only realized the reversible modulation of carrier-type in layered MoTe 2 FETs but also demonstrated MoTe 2 channels with desirable performance, including long-term stability.