Nonthermal and reversible control of neuronal signaling and behavior by midinfrared stimulation.

Various neuromodulation approaches have been employed to alter neuronal spiking activity and thus regulate brain functions and alleviate neurological disorders. Infrared neural stimulation (INS) could be a potential approach for neuromodulation because it requires no tissue contact and possesses a high spatial resolution. However, the risk of overheating and an unclear mechanism hamper its application. Here we show that midinfrared stimulation (MIRS) with a specific wavelength exerts nonthermal, long-distance, and reversible modulatory effects on ion channel activity, neuronal signaling, and sensorimotor behavior. Patch-clamp recording from mouse neocortical pyramidal cells revealed that MIRS readily provides gain control over spiking activities, inhibiting spiking responses to weak inputs but enhancing those to strong inputs. MIRS also shortens action potential (AP) waveforms by accelerating its repolarization, through an increase in voltage-gated K+ (but not Na+) currents. Molecular dynamics simulations further revealed that MIRS-induced resonance vibration of -C=O bonds at the K+ channel ion selectivity filter contributes to the K+ current increase. Importantly, these effects are readily reversible and independent of temperature increase. At the behavioral level in larval zebrafish, MIRS modulates startle responses by sharply increasing the slope of the sensorimotor input-output curve. Therefore, MIRS represents a promising neuromodulation approach suitable for clinical application.

Near-Infrared LEDs Based on Quantum Cutting-Activated Electroluminescence of Ytterbium Ions.

Cesium lead halide perovskite nanocrystals (PNCs) exhibit promising prospects for application in optoelectronic devices. However, electroactivated near-infrared (NIR) PNC light-emitting diodes (LEDs) with emission peaks over 800 nm have not been achieved. Herein, we demonstrate the electroactivated NIR PNC LEDs based on Yb3+-doped CsPb(Cl1-xBrx)3 PNCs with extraordinary high NIR photoluminescence quantum yields over 170%. The fabricated NIR LEDs possess an irradiance of 584.7 µW cm-2, an EQE of 1.2%, and a turn-on voltage of 3.1 V. The ultrafast quantum cutting process from the PNC host to Yb3+ has been revealed as the main mechanism of electroluminescence (EL)-activated Yb3+ for the first time via exploring how the trend between the EL intensity of PNC and Yb3+ varies with different voltages along with the tendency of temperature- and doping-concentration-dependent PL and EL spectra. This work will extend the application of PNCs to optical communication, night-vision devices, and biomedical imaging.

Interaction of Graphitic Carbon Nitride with Cell Membranes: Probing Phospholipid Extraction and Lipid Bilayer Destruction.

Understanding how nanomaterials interact with cell membranes has important implications for ecotoxicology and human health. Here, we investigated the interactions between graphitic carbon nitride (g-C3N4, CN) and red blood cells, a plausible contact target for nanoparticles when they enter the bloodstream. Through a hemolysis assay, the cytotoxicity of CN derived from different precursors was quantitatively assessed, which is highly related to the surface area of CN. Reactive oxygen species (ROS) generation and lipid peroxidation detection confirmed that CN causes rapid cell membrane rupture by a physical interaction mechanism rather than ROS-related chemical oxidation. Dye leakage assay and theoretical simulation indicated that the less-layered CN is prone to folding inward to wrap and extract lipid molecules from cell membranes. The electron-rich inherent pores of CN play a dominant role in capturing the headgroups of phospholipids, whereas the hydrophobic interaction is critical for the anchoring of lipid tails. Our further experimental evidence demonstrated that the destructive extraction of phospholipids from cell membranes by CN occurs primarily in the outer leaflet, and phosphatidylcholine is the most easily extracted lipid. Moreover, the formation of protein corona on CN was found to decrease the nonspecific interactions but increase steric repulsion, thus mitigating CN cytotoxicity. Overall, our data provide a molecular basis for CN's cytotoxicity.

Zn-Alloyed CsPbI3 Nanocrystals for Highly Efficient Perovskite Light-Emitting Devices.

We alloyed Zn2+ into CsPbI3 perovskite nanocrystals by partial substitution of Pb2+ with Zn2+, which does not change their crystalline phase. The resulting alloyed CsPb0.64Zn0.36I3 nanocrystals exhibited an improved, close-to-unity photoluminescence quantum yield of 98.5% due to the increased radiative decay rate and the decreased non-radiative decay rate. They also showed an enhanced stability, which correlated with improved effective Goldschmidt tolerance factors, by the incorporation of Zn2+ ions with a smaller radius than the Pb2+ ions. Simultaneously, the nanocrystals switched from n-type (for CsPbI3) to nearly ambipolar for the alloyed nanoparticles. The hole injection barrier of electroluminescent LEDs was effectively eliminated by using alloyed CsPb0.64Zn0.36I3 nanocrystals, and a high peak external quantum efficiency of 15.1% has been achieved.

Cotemplating synthesis of a rare borate Ni(en)3·Hen·[B9O13(OH)4]·H2O with a chiral polyanonic chain constructed from two different clusters.

Ni(en)3·Hen·[B9O13(OH)4]·H2O was prepared under the cotemplating effect of [Ni(en)3](2+) and Hen(+). It was the first example of a cotemplated borate with an unusual chiral polyanionic chain, which was constructed from [B5O8(OH)2] and [B4O7(OH)2] clusters.

All-optical interrogation of brain-wide activity in freely swimming larval zebrafish.

We introduce an all-optical technique that enables volumetric imaging of brain-wide calcium activity and targeted optogenetic stimulation of specific brain regions in unrestrained larval zebrafish. The system consists of three main components: a 3D tracking module, a dual-color fluorescence imaging module, and a real-time activity manipulation module. Our approach uses a sensitive genetically encoded calcium indicator in combination with a long Stokes shift red fluorescence protein as a reference channel, allowing the extraction of Ca2+ activity from signals contaminated by motion artifacts. The method also incorporates rapid 3D image reconstruction and registration, facilitating real-time selective optogenetic stimulation of different regions of the brain. By demonstrating that selective light activation of the midbrain regions in larval zebrafish could reliably trigger biased turning behavior and changes of brain-wide neural activity, we present a valuable tool for investigating the causal relationship between distributed neural circuit dynamics and naturalistic behavior.

Insights into copper(I) phenylacetylide with in-situ transformation of oxygen and enhanced visible-light response for water decontamination: Cu-O bond promotes exciton dissociation and charge transfer.

The widespread contamination of hexavalent chromium (Cr(VI)), pharmaceuticals and personal care products (PPCPs), and dyes is a growing concern. necessitating the development of convenient and effective technologies for their removal. Copper(I) phenylacetylide (PhC2Cu) has emerged as a promising photocatalyst for environmental remediation. In this study, we introduced a functional Cu-O bond into PhC2Cu (referred to as OrPhC2Cu) by creatively converting the adsorbed oxygen on the surface of PhC2Cu into a Cu-O bond to enhance the efficiency of Cr(VI) photoreduction, PPCPs photodegradation, and dyes photodegradation through a facile vacuum activating method. The incorporation of the Cu-O bond optimized the electron structure of OrPhC2Cu, facilitating exciton dissociation and charge transfer. The exciton dissociation behavior and charge transfer mechanism were systematically investigated for the first time in the OrPhC2Cu system by photoelectrochemical tests, fluorescence and phosphorescence (PH) techniques, and density functional theory (DFT) calculations. Remarkably, the enhanced visible-light response of OrPhC2Cu improved photon utilization and significantly promoted the generation of reactive species (RSs), leading to the highly efficient Cr(VI) photoreduction (98.52% within 25 min) and sulfamethazine photodegradation (94.65% within 60 min), with 3.91 and 5.23 times higher activity compared to PhC2Cu. Additionally, the photocatalytic efficiency of OrPhC2Cu in degrading anionic dyes surpassed that of cationic dyes. The performance of the OrPhC2Cu system in treating electroplating effluent or natural water bodies suggests its potential for practical applications.

Introduce Ce3+ Ions to Realize Enhancement of C+L Band Luminescence of KMnF3: Yb, Er Nanoparticles.

Polymer-based waveguide amplifiers are essential components in integrated optical systems, as their gain bandwidths directly determine the operating wavelength of optical circuits. However, development of the wideband gain media has been challenging, making it difficult to fabricate devices with broadband amplification capability. Rare earth ion-doped nanoparticles (NPs) are a key component in the gain media, and their full width at half maximum (FWHM) of the emission peak decides the final gain bandwidth of the gain media. Here, KMnF3: Yb, Er, Ce@KMnF3: Yb NPs with the broad full width at half maximum (FWHM) of the emission peak covering the S+C band was prepared. The NPs were synthesized using a hydrothermal method, and the FWHM of the emission peak of NPs reached 76 nm under the excitation of a 980 nm laser. The introduction of Ce3+ ions and a core-shell structure coating greatly enhanced the emission intensity of NPs at C band. Since KMnF3: Yb, Er, Ce@KMnF3: Yb NPs have exceptional broadband luminescence properties at C band, KMnF3: Yb, Er, Ce@KMnF3: Yb NPs can be the potential gain medium in the future polymer-based waveguide amplifiers.

Strategy for improvement of molecular oxygen activation capacity of PPECu by chlorine doping for water decontamination.

The activation of molecular oxygen and generation of reactive oxygen species (ROS) play important roles in the efficient removal of contaminants from aqueous ecosystems. Herein, using a simple and rapid solvothermal process, we developed a chlorine-doped phenylethynylcopper (Cl/PPECu) photocatalyst and applied it to visible light degradation of sulfamethazine (SMT) in aqueous media. The Cl/PPECu was optimized to have a 2.52 times higher steady-state concentration of O2•- (3.62 × 10-5 M) and a 28.87 times higher degradation rate constant (0.2252 min-1) for SMT compared to pure PPECu. Further, the effectiveness of Cl/PPECu in treating sulfonamide antibiotics (SAs) in real water systems was verified through an investigation involving natural water bodies, SAs, and ambient sunlight. The energy band structure, DFT calculation and correlation heat map indicated that the addition of chlorine modulated the local electronic structure of PPECu, leading to an improvement in the electron-hole separation, enhanced the O2 activation, and promoted the generation of ROSs. This study not only puts forward innovative ideas for the eco-compatible remediation of environmental pollution using PPECu, but also sheds new light on the activation of oxygen through elemental doping.

Carbon nitride nanotubes anchored with Cu(I) triggers peracetic acid activation with visible light for removal of antibiotic contaminants: Probing mechanisms of non-radical pathways and identifying active sites.

The peracetic acid (PAA)-activation process has attracted much attention in wastewater treatment. However, the low electron efficiency at the interface between heterogeneous catalysts and PAA has affected its practical application. For this study, we developed a carbon nitride hollow-nanotube catalysts with dispersed Cu(I) sites (Cu(I)-TCN) for the photocatalytic activation of PAA for antibiotics degradation. The obtained Cu(I)-TCN catalyst demonstrated an enhanced capacity for visible light harvesting along with increased charge transfer rates. Specifically, the developed Cu(I)-TCN/visible light/PAA system was able to completely remove antibiotics within 20 min, with a kinetic constant that was 25 times higher than a Cu(I)-TCN/visible light system, and 83 times higher than Cu(I)-TCN/PAA systems. Scavenging experiment and electron paramagnetic resonance (EPR) indicated that singlet oxygen was dominant reactive specie for sulfisoxazole (SIZ) removal. Besides, electrochemical tests and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy verified that the electron transfer efficiency of PAA activation was promoted due to the formation of inner-sphere interactions between PAA and Cu(I)-TCN, resulting in the quick removal of antibiotics. Further, after exposure to visible light, the Cu(I)-TCN excited photogenerated electrons which supplemented the electrons consumed in the reaction and drove the valence cycle of Cu ions. Overall, this research offered novel insights into the non-radical pathway for heterogeneous visible light-driven advanced oxidation processes and their potential for practical wastewater remediation.

Superhigh co-adsorption of tetracycline and copper by the ultrathin g-C3N4 modified graphene oxide hydrogels.

Development of economic and efficient absorbent for the simultaneous removal of antibiotics and heavy metals is needed. In this study, a three-dimensional porous ultrathin g-C3N4 (UCN) /graphene oxide (GO) hydrogel (UCN-GH) was prepared by co-assembling of UCN and GO nanosheets via the facile hydrothermal reaction. Characterizations indicated that the addition of UCN significantly decreased the reduction of CO and O-CO related groups of GO during the hydrothermal reaction and introduced amine groups on UCN-GH. The UCN-GH exhibited excellent ability on the co-removal of Cu(II) (qmax = 2.0-2.5 mmol g-1) and tetracycline (TC) (qmax = 1.2-3.0 mmol g-1) from water. The adsorption capacities were increased as UCN mass ratio increasing. The mutual effects between Cu(II) and TC were examined through adsorption kinetics and isotherm models. Characterizations and computational chemistry analysis indicated that Cu(II) is apt to coordinate with the amine groups on UCN than with oxygen groups on GO, which accounts for the enhanced adsorption ability of UCN-GH. In the binary system, Cu(II) acts as a bridge between TC and UCN-GH enhanced the removal of TC. The effects of pH and regular salt ions on the removal of Cu(II)/TC were examined. Moreover, the prepared UCN-GH also showed comparable co-adsorption capacities in practical water/wastewater.

Construction of double-functionalized g-C3N4 heterojunction structure via optimized charge transfer for the synergistically enhanced photocatalytic degradation of sulfonamides and H2O2 production.

Herein, supporting g-C3N4 embedded with benzene-ring (BCN) on P-modified g-C3N4 (PCN) successfully synthesized the homogeneous photocatalyst BCN/PCN (PBCN) via a simple thermal polymerization reaction. Under blue-light (LED) irradiation, the optimized PBCN (0.448 min-1) demonstrated excellent photocatalytic performance, attaining over 74 times the degradation rate for sulfisoxazole (SSZ) in contrast to non-functionalized g-C3N4 (CN, 0.006 min-1). Theoretical calculations revealed that the substitution of heterocyclic rings in the g-C3N4 triazine networks with benzene-rings enabled them to serve as electron donors, while promoting photoinduced spatial charge dissociation. Further, the carrier PCN tended to serve as electron acceptors to form electron-rich corner-phosphorous sites. Reactive species experiments demonstrate that the O2˙- and h+ constituted the primary photocatalytic mechanism of SSZ degradation. The potential SSZ degradation routes were predicted based on the transformation products via mass spectrometry. Finally, the composite materials also exhibited excellent photocatalytic activity in the conversion of solar energy to chemical energy (H2O2). This study guides the rational modification of g-C3N4-based semiconductors to achieve green energy production and beneficial ecological applications.

Synchronous construction of a porous intramolecular D-A conjugated polymer via electron donors for superior photocatalytic decontamination.

The development of conjugated polymers with intramolecular donor-acceptor (D-A) units has the capacity to enhance the photocatalytic performance of carbon nitride (g-C3N4) for the removal of antibiotics from ambient ecosystems. This strategy addresses the challenge of narrowing the band gap of g-C3N4 while maintaining its high LUMO position. For this study, we introduced the above donor units into g-C3N4 to construct intramolecular D-A structures through the copolymerization of dicyandiamide with creatinine, which strategically extended light absorption into the green region and expedited photoelectron separation. The introduction of electron donor blocks kept the LUMO distributed on the melem, which maintained the high LUMO energy level of the copolymer with the potential to generate oxygen radicals. The as-prepared porous D-A conjugated polymer enhanced the photocatalytic degradation of sulfisoxazole with kinetic constants 5.6 times higher than that of g-C3N4 under blue light and 15.3 times higher under green light. Furthermore, we surveyed the degradation mechanism including the effective active species and degradation pathways. This study offers a new perspective for the synchronous construction of a porous intramolecular D-A conjugated polymer to enhance water treatment and environmental remediation capacities.

Construction of dual transfer channels in graphitic carbon nitride photocatalyst for high-efficiency environmental pollution remediation: Enhanced exciton dissociation and carrier migration.

Graphitic carbon nitride (g-C3N4) is a promising candidate for photocatalysis, but exhibits moderate activity due to strongly bound excitons and sluggish charge migration. The dissociation of excitons to free electrons and holes is considered an effective strategy to enhance photocatalytic activity. Herein, a novel boron nitride quantum dots (BNQDs) modified P-doped g-C3N4 photocatalyst (BQPN) was successfully prepared by thermal polymerization method. Photoluminescence techniques and photoelectrochemical tests demonstrated that the introduction of P atoms and BNQDs promoted the dissociation of excitons and the migration of photogenerated carriers. Specifically, theoretical calculations revealed that P substitutions were the sites of pooled electrons, while BNQDs were the excellent photogenerated hole extractors. Accordingly, compared with g-C3N4, the BQPN showed improved performance in degrading four non-steroidal anti-inflammatory drugs (NSAIDs) under visible light irradiation. This work not only establishes an in-depth understanding of excitonic regulation in g-C3N4, but also offers a promising photocatalytic technology for environmental remediation.

Removal of lead ions by two FeMn oxide substrate adsorbents.

Lead pollution has become a global concern due to its ubiquity and persistence. This study describes two FeMn oxide substrate adsorbents, namely, FeMn binary oxides (FMBO) and mesoporous FeMn binary oxide (MFMBO) covered with tannic acid film (FMBO@TA-Fe3+ and MFMBO@TA-Fe3+), for the treatment of Pb2+ in water. The characterization results showed that TA was successfully coated onto the surfaces of FMBO and MFMBO. The maximum capacities of Pb2+ on FMBO@TA-Fe3+ and MFMBO@TA-Fe3+ were 322.08 and 357.14 mg g-1, respectively, which were twice those of FMBO and MFMBO. The adsorption of Pb2+ on the adsorbents was a spontaneous, endothermic process with increasing disorder through thermodynamics studies. An overall mechanism was proposed for Pb2+ adsorption, the improved adsorption performance of FMBO@TA-Fe3+ and MFMBO@TA-Fe3+ is ascribed to the mesoporous characteristics and the introduction of hydroxyl groups. Further investigation indicated the adsorption of Pb2+ could be attributed to electrostatic interactions on FMBO@TA-Fe3+ and MFMBO@TA-Fe3+, and cation exchange existed through the formation of these internal surface complexes. The Pb2+-loaded adsorbents could be effectively desorbed in a dilute hydrochloric acid solution, promoting recycling and reuse of the regenerated adsorbents. These results warrant the promising application of FMBO@TA-Fe3+ and MFMBO@TA-Fe3+ for the removal of Pb2+, and this work first proposed TA film-modified FMBO and MFMBO to improve its adsorption capacity in the application of environmental remediation.

High Color-Purity Red, Green, and Blue-Emissive Core-Shell Upconversion Nanoparticles Using Ternary Near-Infrared Quadrature Excitations.

Development of multicolor-emitting upconversion nanoparticles (UCNPs) is of significant importance for applications in optical encoding, anti-counterfeiting, display, and bioimaging. However, realizing the orthogonal three-primary color (TPC) upconversion luminescence in a single nanoparticle remains a huge challenge. Herein, we have rationally designed core-multishell-structured NaYF4 UCNPs through regulating the dopant concentration, composition of luminescent layers, and shell position and thickness, which are capable of emitting red, green, and blue luminescence with high color purity in response to ternary near-infrared quadrature excitations (1560/808/980 nm). Moreover, their high color purity is well retained with varying excitation power densities. This orthogonal TPC emissions property of such UCNPs endows them with great promise in the field of security. As a proof-of-concept, we have demonstrated the feasibility of combining such UCNPs with MnO2 nanosheets for information encryption and decryption. This work not only offers a new way to achieve TPC upconversion luminescence at a single nanoparticle level but also broadens the scope of application for security protection.

Integration of oxygen vacancies into BiOI via a facile alkaline earth ion-doping strategy for the enhanced photocatalytic performance toward indometacin remediation.

Bismuth oxyiodide (BiOI) has garnered intense attention in the field of photocatalysis for environmental remediation; however, it suffers from a high electron-hole recombination rate. In this study, for the first time, we report on a facile strategy for the creation of oxygen vacancies in BiOI via strontium (Sr2+) doping. The as-prepared 0.45-SrBiOI demonstrated significantly enhanced photocatalytic degradation of indometacin under visible light exposure, which was almost 10 folds higher than pristine BiOI. This augmented photocatalytic performance was ascribed to the accelerated separation of charge carriers by oxygen vacancies, as well as Sr ion trapping electrons. Reactive species determination experiments revealed that O2▪-, 1O2, and h+ were the dominant active species. Finally, potential indometacin degradation pathways were proposed based on the identification of degradation by-products and theoretical calculations. This study offers new perspectives for the synthesis of highly efficient and cost effective BiOI-based photocatalysts, and provides a promising strategy toward advanced environmental remediation.

Synthesis of a carbon dots modified g-C3N4/SnO2 Z-scheme photocatalyst with superior photocatalytic activity for PPCPs degradation under visible light irradiation.

As an emerging carbon nanomaterial, carbon dots (CDs) have superior prospects for applications in the area of photocatalysis due to their unique optical and electronic properties. In this study, a novel CDs modified g-C3N4/SnO2 photocatalyst (CDs/g-C3N4/ SnO2) was successfully synthesized by the thermal polymerization. Under visible light irradiation, the resulting CDs/g-C3N4/SnO2 photocatalyst exhibited excellent photocatalytic activity for the degradation of indomethacin (IDM). It was demonstrated that a 0.5 % loading content of CDs led to the highest IDM degradation rate, which was 5.62 times higher than that of pristine g-C3N4. This improved photocatalytic activity might have been attributed to the unique up-conversion photoluminescence (PL) properties and efficient charge separation capacities of the CDs. Moreover, the combination of g-C3N4 with SnO2 improved the separation of photoinduced carriers and augmented the specific surface area. Reactive species (RSs) scavenging experiments and electron spin resonance (ESR) revealed that superoxide radical anions (O2·-) and photogenerated holes (h+) played critical roles during the photocatalytic process. The results of the detection of H2O2 and ESR confirmed that CDs/g-C3N4/ SnO2 was a Z-scheme heterojunction photocatalyst. Further, HRAM LC-MS/MS was employed to identify the byproducts of IDM, and the major IDM degradation pathways of the CDs/g-C3N4/SnO2 photocatalyst were proposed. This study provides new ideas for the design of novel CDs modified photocatalysts for environmental remediation.

Ultrathin Ag2WO4-coated P-doped g-C3N4 nanosheets with remarkable photocatalytic performance for indomethacin degradation.

As a metal-free photocatalyst, the photocatalytic activity of graphitic carbon nitride (g-C3N4) remains restricted due to an insufficient visible-light absorption capacity, the rapid recombination of photoinduced carriers, and low surface area. Consequently, P-doped g-C3N4 (PCN) was successfully prepared via a single -step thermal polymerization technique using phytic acid biomass and urea, which exhibited remarkable photocatalytic activity for the degradation of indometacin (IDM). The IDM degradation rate was 7.1 times greater than that of pristine g-C3N4 (CN). Furthermore, Ag2WO4 was loaded onto the surface of the PCN, which formed a Z-scheme heterostructure that promoted the separation of photogenerated carriers. According to analyses of the chemical binding states of PCN, P atoms replaced carbon atoms in the CN framework. According to electron localization function analysis, the low ELF values of P-N facilitated the transfer of photoelectrons. The results of active species scavenging experiments confirmed that superoxide radicals were the primary active species in the photocatalytic degradation system. Finally, the photocatalytic degradation pathways of IDM were predicted through the identification of by-products and IDM reaction sites.

One-step synthesis of phosphorus/oxygen co-doped g-C3N4/anatase TiO2 Z-scheme photocatalyst for significantly enhanced visible-light photocatalysis degradation of enrofloxacin.

Anatase TiO2 nanoparticles coated with P and O co-doped g-C3N4 were prepared via a single-step procedure. The resulting POCN/anatase TiO2 demonstrated remarkable performance in the degradation of enrofloxacin (ENFX). The photocatalytic activity of this heterojunction was 28.9 and 3.71 times better than that of the CN and anatase TiO2, respectively. The microtopography of the POCN/anatase TiO2 was revealed in this study. Co-doping with P and O increased the visible light adsorption capacity of the g-C3N4, whereas the anatase TiO2 nanoparticles enhanced the adsorption properties of the ENFX and the separation of the photoinduced carriers of the POCN/anatase TiO2. The O2·- and h+ were the main reactive oxidative species in the photocatalytic degradation of ENFX. The results of the detection of H2O2 and ESR confirmed that POCN/anatase TiO2 was a type Z-scheme photocatalyst. Finally, the ENFX degradation pathways were estimated through the detection of by-products.