Enabling Visible-Light-Charged Near-Infrared Persistent Luminescence in Organics by Intermolecular Charge Transfer.

Visible light is a universal and user-friendly excitation source; however, its use to generate persistent luminescence (PersL) in materials remains a huge challenge. Herein, we apply the concept of intermolecular charge transfer (xCT) in typical host-guest molecular systems, which allows for a much lower energy requirement for charge separation, thus enabling efficient charging of near-infrared (NIR) PersL in organics by visible light (425-700 nm). Importantly, NIR PersL in organics occurs via the trapping of electrons from charge-transfer aggregates (CTAs) into constructed trap states with trap depths of 0.63-1.17 eV, followed by the detrapping of these electrons by thermal stimulation, resulting in a unique light-storage effect and long-lasting emission up to 4.6 h at room temperature. The xCT absorption range was modulated by changing the electron-donating ability of a series of acenaphtho[1,2-b]pyrazine-8,9-dicarbonitrile-based CTAs, and the organic PersL was tuned from 681 to 722 nm. This study on xCT interaction-induced NIR PersL in organic materials provides a major step forward in understanding the underlying luminescence mechanism of organic semiconductors and these findings are expected to promote their applications in optoelectronics, energy storage, and medical diagnosis. This article is protected by copyright. All rights reserved.

Capsaicin combined with stem cells improved mitochondrial dysfunction in PIG3V cells, an immortalized human vitiligo melanocyte cell line, by inhibiting the HSP70/TLR4/mTOR/FAK signaling axis.

BACKGROUND: Vitiligo is a common autoimmune skin disease. Capsaicin has been found to exert a positive effect on vitiligo treatment, and mesenchymal stem cells (MSCs) are also confirmed to be an ideal cell type. This study aimed to explore the influence of capsaicin combined with stem cells on the treatment of vitiligo and to confirm the molecular mechanism of capsaicin combined with stem cells in treating vitiligo. METHODS AND RESULTS: PIG3V cell proliferation and apoptosis were detected using CCK-8 and TUNEL assays, MitoSOX Red fluorescence staining was used to measure the mitochondrial ROS level, and JC-1 staining was used to detect the mitochondrial membrane potential. The expression of related genes and proteins was detected using RT‒qPCR and Western blotting. Coimmunoprecipitation was used to analyze the protein interactions between HSP70 and TLR4 or between TLR4 and mTOR. The results showed higher expression of HSP70 in PIG3V cells than in PIG1 cells. The overexpression of HSP70 reduced the proliferation of PIG3V cells, promoted apoptosis, and aggravated mitochondrial dysfunction and autophagy abnormalities. The expression of HSP70 could be inhibited by capsaicin combined with MSCs, which increased the levels of Tyr, Tyrp1 and DCT, promoted the proliferation of PIG3V cells, inhibited apoptosis, activated autophagy, and improved mitochondrial dysfunction. In addition, capsaicin combined with MSCs regulated the expression of TLR4 through HSP70 and subsequently affected the mTOR/FAK signaling pathway CONCLUSIONS: Capsaicin combined with MSCs inhibits TLR4 through HSP70, and the mTOR/FAK signaling pathway is inhibited to alleviate mitochondrial dysfunction and autophagy abnormalities in PIG3V cells.

Toxic effect and mRNA mechanism of moon dust simulant induced pulmonary inflammation in rats.

Moon dust presents a significant hazard to manned moon exploration missions, yet our understanding of its toxicity remains limited. The objective of this study is to investigate the pattern and mechanism of lung inflammation induced by subacute exposure to moon dust simulants (MDS) in rats. SD rats were exposed to MDS and silica dioxide through oral and nasal inhalation for 6 hours per day continuously for 15 days. Pathological analysis indicated that the toxicity of MDS was lower than that of silica dioxide. MDS led to a notable recruitment and infiltration of macrophages in the rat lungs. Material characterization and biochemical analysis revealed that SiO2, Fe2O3, and TiO2 could be crucial sources of MDS toxicity. The study revealed that MDS-induced oxidative stress response can lead to pulmonary inflammation, which potentially may progress to lung fibrosis. Transcriptome sequencing revealed that MDS suppresses the PI3K-AKT signaling pathway, triggers the Tnfr2 non-classical NF-kB pathway and IL-17 signaling pathway, ultimately causing lung inflammation and activating predominantly antioxidant immune responses. Moreover, the study identified the involvement of upregulated genes IL1b, csf2, and Sod2 in regulating immune responses in rat lungs, making them potential key targets for preventing pulmonary toxicity related to moon dust exposure. These findings are expected to aid in safeguarding astronauts against the hazardous effects of moon dust and offer fresh insights into the implications and mechanisms of moon dust toxicity.

Constructing cuprous oxide-modified zinc tetraphenylporphyrin ultrathin nanosheets heterojunction for enhanced photocatalytic carbon dioxide reduction to methane.

The application of supermolecular naonostructures in the photocatalytic carbon dioxide reduction reaction (CO2RR) has attracted increasing attentions. However, it still faces significant challenges, such as low selectivity for multi-electron products and poor stability. Here, the cuprous oxide (Cu2O)-modified zinc tetraphenylporphyrin ultrathin nanosheets (ZnTPP NSs) are successfully constructed through the aqueous chemical reaction. Comprehensive characterizations confirm the formation of type-II heterojunction between Cu2O and ZnTPP in Cu2O@ZnTPP, and the electron transfer from Cu2O to ZnTPP through the Zn-O-Cu bond under the static contact. Under the visible-light irradiation (λ > 420 nm), the optimized Cu2O@ZnTPP sample as catalyst for photocatalytic CO2RR exhibits the methane (CH4) evolution rate of 120.9 µmol/g/h, which is âˆ¼ 4 and âˆ¼ 10 times those of individual ZnTPP NSs (28.0 µmol/g/h) and Cu2O (12.8 µmol/g/h), respectively. Meanwhile, the CH4 selectivity of âˆ¼ 98.7 % and excellent stability can be achieved. Further experiments reveal that Cu2O@ZnTPP has higher photocatalytic conversion efficiency than Cu2O and ZnTPP NSs, and the photoinduced electron transfer from ZnTPP to Cu2O can be identified via the path of ZnTPP→ (ZnTPP•ZnTPP)*→ ZnTPP-→ Zn-O-Cu â†’ Cu2O. Consequently, Cu2O@ZnTPP exhibits a shorter electron-hole separation lifetime (3.3 vs. 9.3 ps) and a longer recombination lifetime (23.1 vs. 13.4 ps) than individual ZnTPP NSs. This work provides a strategy to construct the organic nanostructures for photocatalytic CO2RR to multi-electron products.

Simultaneously tuning the luminescent color and realizing an optical temperature sensor by negative thermal expansion in Sc2(WO4)3:Tb/Eu phosphors.

At present, many researchers are focusing on trivalent lanthanide (Ln3+)-doped thermally enhanced upconversion luminescent (UCL) materials with negative thermal expansion (NTE) properties. However, selective anti-thermal quenching downshifting emissions of the activator and thermal quenching of the sensitizer in a phosphor with NTE properties are not implemented. Herein, Tb3+/Eu3+ co-doped Sc2(WO4)3 phosphors synthesized by the solid-state method are explored in selectively enhanced red emission (Eu3+:5D0 → 7F2) due to the energy-transfer efficiency from Tb3+ to Eu3+ and the promoted radiative transition probability. The selective thermally quenched green emission (Tb3+:5D4 → 7F5) is owing to the change of energy transfer from Tb3+ to Eu3+ as the temperature increased. Moreover, under ultraviolet 365 nm excitation, the thermally stimulated color emission tuned from yellow to red with the increase in temperature. Based on the radically different thermal response downshifting the luminescence of the activator and sensitizer, the luminescence intensity ratio (LIR) of non-thermally coupled levels (NTCLs) for 5D0 (Eu3+) and 5D4 (Tb3+) is adopted for optical temperature sensing. The optimal relative sensitivity of temperature sensing in the Sc2(WO4)3:25%Tb3+/3%Eu3+ sample could reach 2.94% K-1 at 347 K. All these indicate that this Sc2(WO4)3:Tb3+/Eu3+ material is a promising candidate for high-sensitivity optical temperature sensing.

Logistic analysis of the recurrence of laparoscopic percutaneous extraperitoneal repair of pediatric inguinal hernia: A report of 486 cases.

BACKGROUND: Although the laparoscopic treatment of pediatric inguinal hernia (PIH) has more benefits than traditional surgery, it is difficult to completely avoid the problem of recurrence. The aim of this study was to use a logistic regression model to investigate the causes of recurrence after laparoscopic percutaneous extraperitoneal repair (LPER) of PIH. PATIENTS AND METHODS: From June 2017 to December 2021, 486 cases of PIH were performed using LPER in our department. We utilized a two-port approach to implement LPER for PIH. All cases were followed up and the recurrent cases were recorded in detail. We used a logistic regression model to analyze the clinical data in order to find the reasons for recurrence. RESULTS: We completed 486 cases with an internal inguinal ostium high ligation using laparoscopic surgery without conversion. Patients were followed for 10-29 months with an average of 18.2 months and 8 cases had recurrent ipsilateral hernia, including 4 recurrent cases in 89 cases (4.49%) using absorbable suture, 1 in 7 cases (14.29%) with internal inguinal ostium larger than 25 mm, 2 in 26 cases (7.69%) with BMI greater than 21, 2 in 41 cases (4.88%) with postoperative chronic constipation. The total recurrence rate was 1.65%. A foreign body reaction occurred in 2 cases, there were no complications such as scrotal hematoma, trocar umbilical hernia and testicular atrophy, and no deaths in this study. Univariate logistic regression analysis showed that patient BMI, ligation suture, diameter of the internal inguinal ostium and postoperative chronic constipation were significant variables (P values 0.093, 0.027, 0.060 and 0.081). The multivariate logistic regression analysis showed that the ligation suture and the diameter of the internal inguinal ostium were the main risk factors for postoperative recurrence, the odds ratio (OR) value were 5.374 and 2.801, the P values 0.018 and 0.046, and the 95% CI were 2.513-11.642 and 1.134-9.125. The area under ROC curve (AUC) for the logistic regression model was 0.735 (the 95% CI 0.677-0.801, P < 0.01). CONCLUSION: An LPER for PIH is a safe and effective operation, but there still remains a small probability of recurrence. In order to reduce the recurrence rate of LPER, we should improve surgical skills, choose an appropriate ligature and avoid using LPER for a huge internal inguinal ostium (especially over 25 mm). It is appropriate to be converted to open surgery for the patients with a very wide internal inguinal ostium.

Unveiling the energy transfer mechanism between aqueous colloidal NIR-II quantum dots and water.

Hydrophilic semiconductor quantum dots (QDs) with emission in the second near-infrared window (NIR-II) have been widely studied in bioimaging applications. In such cases, QDs are usually dispersed in water. As is known, water has strong absorbance in the NIR-II region. However, investigations on the interaction between NIR-II emitters and water molecules are ignored in previous studies. Herein, we synthesized a series of mercaptoundecanoic acid-coated silver sulfide (Ag2S/MUA) QDs with various emissions that partially or completely overlapped with the absorbance of water at 1200 nm. By constructing a hydrophobic interface of cetyltrimethylammonium bromide (CTAB) with MUA on the Ag2S QDs surface via forming an ionic bond, significant enhancement of Ag2S QDs photoluminescence (PL) intensity was observed, as well as a prolonged lifetime. These findings suggest that there is an energy transfer between Ag2S QDs and water in addition to the classical resonance absorption. Transient absorption and fluorescence spectra results revealed that the increased PL intensities and lifetime of Ag2S QDs originated from the suppressed energy transfer from Ag2S QDs to the water due to the CTAB bridged hydrophobic interfaces. This discovery is important for a deeper understanding of the photophysical mechanisms of QDs and their applications.

Topology Optimization Method of a Cavity Receiver and Built-In Net-Based Flow Channels for a Solar Parabolic Dish Collector.

The design of a thermal cavity receiver and the arrangement of the fluid flow layout within it are critical in the construction of solar parabolic dish collectors, involving the prediction of the thermal-fluid physical field of the receiver and optimization design. However, the thermal-fluid analysis coupled with a heat loss model of the receiver is a non-linear and computationally intensive solving process that incurs high computational costs in the optimization procedure. To address this, we implement a net-based thermal-fluid model that incorporates heat loss analysis to describe the receiver's flow and heat transfer processes, reducing computational costs. The physical field results of the net-based thermal-fluid model are compared with those of the numerical simulation, enabling us to verify the accuracy of the established thermal-fluid model. Additionally, based on the developed thermal-fluid model, a topology optimization method that employs a genetic algorithm (GA) is developed to design the cavity receiver and its built-in net-based flow channels. Using the established optimization method, single-objective and multi-objective optimization experiments are conducted under inhomogeneous heat flux conditions, with objectives including maximizing temperature uniformity and thermal efficiency, as well as minimizing the pressure drop. The results reveal varying topological characteristics for different optimization objectives. In comparison with the reference design (spiral channel) under the same conditions, the multi-objective optimization results exhibit superior comprehensive performance.

Seven-photon absorption from Na+/Bi3+-alloyed Cs2AgInCl6 perovskites.

Nonlinear multi-phonon (2-7) absorption in the Na+/Bi3+-alloyed Cs2AgInCl6 lead-free double perovskites with ∼100% photoluminescence quantum yield and superior stability is observed for the first time, which can be pumped by a femtosecond laser in a wide spectral range (800-2600 nm). First-principles calculations verify that the parity-forbidden transition from the valence band maximum and conduction band minimum (at the Γ point) is not broken by Na+/Bi3+ doping, and strong optical band-to-band absorption occurs at the L&X points. Time-resolved emission spectra evidence that single-photon and multi-photon pumping leads to the same self-trapped exciton transition and high-order nonlinear absorption will not induce a remarkable thermal effect. Finally, we demonstrate that the Cs2Na0.4Ag0.6In0.99Bi0.01Cl6 DP shows great potential for next-generation wavelength-selective and highly sensitive multiphoton imaging applications.

Multiexciton Generation from a 2D Organic-Inorganic Hybrid Perovskite with Nearly 200% Quantum Yield of Red Phosphorescence.

2D organic-inorganic hybrid perovskites (OIHPs) show obvious advantages in the field of optoelectronics due to their high luminescent stability and good solution processability. However, the thermal quenching and self-absorption of excitons caused by the strong interaction between the inorganic metal ions lead to a low luminescence efficiency of 2D perovskites. Herein, a 2D Cd-based OIHP phenylammonium cadmium chloride (PACC) with a weak red phosphorescence (ΦP  < 6%) at 620 nm and a blue afterglow is reported. Interestingly, the Mn-doped PACC exhibits very strong red emission with nearly 200% quantum yield and 15 ms lifetime, thus resulting in a red afterglow. The experimental data prove that the doping of Mn2+ not only induces the multiexciton generation (MEG) process of the perovskite, avoiding the energy loss of inorganic excitons, but also promotes the Dexter energy transfer from organic triplet excitons to inorganic excitons, thus realizing the superefficient red-light emission of Cd2+ . This work suggests that guest metal ions can induce host metal ions to realize MEG in 2D bulk OIHPs, which provides a new idea for the development of optoelectronic materials and devices with ultrahigh energy utilization.

Ultrasensitive Urinary Diagnosis of Organ Injuries Using Time-Resolved Luminescent Lanthanide Nano-bioprobes.

Urinary sensing of synthetic biomarkers that are released into urine after specific activation in an in vivo disease environment is an emerging diagnosis strategy to overcome the insensitivity of a previous biomarker assay. However, it remains a great challenge to achieve sensitive and a specific urinary photoluminescence (PL) diagnosis. Herein, we report a novel urinary time-resolved PL (TRPL) diagnosis strategy by exploiting europium complexes of diethylenetriaminepentaacetic acid (Eu-DTPA) as synthetic biomarkers and designing the activatable nanoprobes. Notably, TRPL of Eu-DTPA in the enhancer can eliminate the urinary background PL for ultrasensitive detection. We achieved sensitive urinary TRPL diagnosis of mice kidney and liver injuries by using simple Eu-DTPA and Eu-DTPA-integrated nanoprobes, respectively, which cannot be realized by traditional blood assays. This work demonstrates the exploration of lanthanide nanoprobes for in vivo disease-activated urinary TRPL diagnosis for the first time, which might advance the noninvasive diagnosis of diverse diseases via tailorable nanoprobe designs.

Carboxylated superparamagnetic Fe3O4 nanoparticles modified with 3-amino propanol and their application in magnetic resonance tumor imaging.

BACKGROUND: Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles are of potential magnetic resonance imaging (MRI) contrast agents for tumor diagnosis. However, ultrasmall particle size or negative surface charge lead to relative short half-life which limit the utilization of USPIO for in vivo MRI contrast agents. METHODS: Superparamagnetic Fe3O4 nanoparticles coated with polyacrylic acid (PAA)were synthetized, and modified by 3-amino propanol and 3-diethyl amino propyl amine. The characteristics of superparamagnetic Fe3O4 nanoparticles were investigated through transmission electron microscopy, X-ray diffraction analysis, Zata potential analysis, thermogravimetric analysis, and relaxation properties analysis. Magnetic resonance imaging animal experiment was performed. RESULTS: The synthetized nanoparticles were irregular spherical, with small particle size, few agglomeration, and good dispersion in water. After modification, the potential fluctuation of nanoparticles was small, and the isoelectric point of nanoparticles changed to high pH. After 3-amino propanol modification, the weight loss of the curve from 820 to 940 °C was attributed to the decomposition of 3-amino propanol molecules on the surface. The T1 relaxation rate of nanoparticles changed little before and after modification, which proved that the modification didn't change the relaxation time. Brighter vascular images were observed after 3-amino propanol modification through measurement of magnetic resonance tumor imaging. CONCLUSION: These data indicated the Fe3O4 nanoparticles modified by 3-amino propanol should be a better contrast agent in the field of magnetic resonance tumor imaging.

Polarity-dependent emission from hydroxyl-free carbon nanodots.

Surface groups of carbon nanodots (CNDs) play a key role in modulating their photoluminescence (PL) properties. However, most of the as-prepared CNDs are complex mixtures of CNDs bearing different surface groups. Thus, the purification of CNDs is essential to reveal the PL mechanism of CNDs. Herein, we present a facile method to synthesize hydroxyl (-OH) free CNDs, followed by intelligently guided column chromatographic separation of CNDs with specific functional groups according to their degree of polarity. After systematic investigation of the separated non-polar CNDs (NP-CNDs) and polar CNDs (P-CNDs), it is revealed that radiative photon emission dominates in the NP-CNDs, which exhibits excitation wavelength-independent emissions. In contrast, an increase in the solvent polarity of P-CNDs improves Frank-Condon excited state stabilization to achieve excitation wavelength-dependent emissions. In particular, white-light emitting P-CNDs with CIE coordinates of (0.332, 0.336) are produced. These findings provide new insights into the nature of the PL mechanism for CNDs, which may pave the way towards the rational design of highly efficient and emission tunable CNDs for various applications.

Development of a New Multiple Stimuli-Responsive Fluorescent Material Using the Minus Strategy Based on the Structure of Tetraphenyl-1,3-butadiene.

In this study, we designed and synthesized a new class of aggregation-induced emission luminogens, which was inspired and developed from the structure of tetraphenyl-1,3-butadienes derivative (TPB-1) through the minus strategy by removing one of the phenyl groups. Among them, L1 and L4 exhibited an aggregation-induced emission effect and multistimuli-responsive chromic behavior. Moreover, two types of single crystals of L1 were obtained, and their different emission behaviors were elucidated clearly by analyzing the single-crystal data.

Compact ultrabroadband light-emitting diodes based on lanthanide-doped lead-free double perovskites.

Impurity doping is an effective approach to tuning the optoelectronic performance of host materials by imparting extrinsic electronic channels. Herein, a family of lanthanide (Ln3+) ions was successfully incorporated into a Bi:Cs2AgInCl6 lead-free double-perovskite (DP) semiconductor, expanding the spectral range from visible (Vis) to near-infrared (NIR) and improving the photoluminescence quantum yield (PLQY). After multidoping with Nd, Yb, Er and Tm, Bi/Ln:Cs2AgInCl6 yielded an ultrabroadband continuous emission spectrum with a full width at half-maximum of ~365 nm originating from intrinsic self-trapped exciton recombination and abundant 4f-4f transitions of the Ln3+ dopants. Steady-state and transient-state spectra were used to ascertain the energy transfer and emissive processes. To avoid adverse energy interactions between the various Ln3+ ions in a single DP host, a heterogeneous architecture was designed to spatially confine different Ln3+ dopants via a "DP-in-glass composite" (DiG) structure. This bottom-up strategy endowed the prepared Ln3+-doped DIG with a high PLQY of 40% (nearly three times as high as that of the multidoped DP) and superior long-term stability. Finally, a compact Vis-NIR ultrabroadband (400~2000 nm) light source was easily fabricated by coupling the DiG with a commercial UV LED chip, and this light source has promising applications in nondestructive spectroscopic analyses and multifunctional lighting.

New Rofecoxib-Based Mechanochromic Luminescent Materials and Investigations on Their Aggregation-Induced Emission, Acidochromism, and LD-Specific Bioimaging.

Development of new mechanochromic luminescent (MCL) materials from aggregation-induced emission luminogens (AIEgens) has attracted wide attention due to their potential application in multiple areas. However, rational design and crafting of new MCL materials from the simple AIEgens skeleton is still a big challenge because of the undesirable concentration quenching effect. In this study, we have constructed a new class of MCL materials by adding one phenyl as a new rotator and incorporating one pair of electron donor (D) and acceptor (A) into the system of rofecoxib skeleton. This strategy endowed the compounds (Y1-Y8) with tunable emission behavior and some of them with the AIE effect and reversible MCL behavior. These properties may be caused by the highly twisted conformation and loosely molecular packing modes, which were elucidated clearly by analyzing the data of single-crystal X-ray diffraction, powder X-ray diffraction, and differential scanning calorimetry. Further investigation revealed that Y7 displayed acidochromic property due to the protonation of the nitrogen atom. Moreover, Y7, as a typical compound, showed its potential applications in the area of anticounterfeiting, pH sensor, and LD-specific bioimaging.

Development of Rofecoxib-Based Fluorophores from ACQ to AIE by Positional Regioisomerization.

The development of aggregation-induced emission luminogens (AIEgens) has attracted increasing attention due to their potential applications in various areas in recent years. In this study, a facile conversion from aggregation-caused quenching (ACQ) to aggregation-induced emission (AIE) was achieved by an efficient regioisomerization strategy based on the rofecoxib scaffold. Two compounds, named PYR2 and PYR4, were identified as regioisomers of rofecoxib derivatives to show dramatically different fluorescent properties. Compound PYR2 with an ortho-substituted piperidine group showed typical AIE activity while compound PYR4 with a para-piperidine group exhibited typical ACQ behavior. Notably, compound PYR2 showed polymorphism with two forms of crystals. It was also endowed with reversible mechanochromic luminescence and acidochromic properties. The different fluorescent properties were elucidated by UV/Vis absorption spectroscopy, powder X-ray diffraction, differential scanning calorimetry, and thermogravimetric analyses. Its application as a security ink and in lipid droplets imaging have been demonstrated.

Boosting the Self-Trapped Exciton Emission in Alloyed Cs2 (Ag/Na)InCl6 Double Perovskite via Cu+ Doping.

Fundamental understanding of the effect of doping on the optical properties of 3D double perovskites (DPs) especially the dynamics of self-trapped excitons (STEs) is of vital importance for their optoelectronic applications. Herein, a unique strategy via Cu+ doping to achieve efficient STE emission in the alloyed lead-free Cs2 (Ag/Na)InCl6 DPs is reported. A small amount (1.0 mol%) of Cu+ doping results in boosted STE emission in the crystals, with photoluminescence (PL) quantum yield increasing from 19.0% to 62.6% and excitation band shifting from 310 to 365 nm. Temperature-dependent PL and femtosecond transient absorption spectroscopies reveal that the remarkable PL enhancement originates from the increased radiative recombination rate and density of STEs, as a result of symmetry breakdown of the STE wavefunction at the octahedral Ag+ site. These findings provide deep insights into the STE dynamics in Cu+ -doped Cs2 (Ag/Na)InCl6 , thereby laying a foundation for the future design of new lead-free DPs with efficient STE emission.

Laser-direct-writing of molecule-like Agmx+ nanoclusters in transparent tellurite glass for 3D volumetric optical storage.

In situ constructing program-designed nanostructures via laser-direct-writing (LDW) has proved to be a reliable strategy for optical storage (OS). Herein, a kind of low-melting Ag+-doped TeO2-ZnO-Na2O (TZN) tellurite glass has been demonstrated as an ideal LDW OS medium. Microstructural and spectroscopic studies reveal the generation of molecule-like Agmx+ nanoclusters featured with a broad emission band in the orange-red region upon laser irradiation. Probing the laser-glass interaction yields evidences of the spatial distribution of Ag species responsive to laser-induced thermoelastic pressure wave oscillation, as well as the heat-driven migration/aggregation of Ag species along the radial direction of the laser spot. Raman analyses disclose the loose network of TZN-glass convenient for Ag+ mobility and the increased network connectivity when Agmx+ nanoclusters are precipitated out. Combined with the XPS result of Ag+ → Ag0 reduction, the possible formation mechanism of Ag nanoclusters stabilized in glass has been proposed. In a proof-of-concept experiment, 3D volumetric OS in the TZN glass has been demonstrated, showing optical data encoding/decoding in the form of characters and image patterns.

Boosting Visible-Light-Driven Photocatalytic Hydrogen Production through Sensitizing TiO2 via Novel Nanoclusters.

Improving the light utilization and electron-hole separation efficiency plays a central role in photocatalysis for converting light energy to hydrogen energy. Herein, for the first time, a stable, highly dispersible discrete T4 [Cd3In17Se31]5- cluster is developed as a novel photosensitizer to sensitize TiO2 for photocatalytic hydrogen production. Compared with pristine TiO2 (near zero) and the T4 clusters (19.5 µmol g-1 h-1) that exhibit low hydrogen evolution activities, the T4/TiO2 composite, constructed from traces of 0.127 mol % T4 cluster-sensitized TiO2, exhibits a dramatically improved photocatalytic activity of 328.2 µmol g-1 h-1, highlighting that the photocatalytic efficiency strongly correlates with that of the T4 cluster. In the meantime, the T4/TiO2 composites are highly stable, remaining robust in a long-time test of 50 h for photocatalytic hydrogen production. Ultrafast transient absorption spectroscopy, in combination with electrochemical analyses, steady-state and time-resolved photoluminescence, and density functional theory calculations, indicates that the T4 cluster not only serve as a photosensitizer to absorb visible light but also form a heterojunction between the interface of the T4 cluster and TiO2 to accelerate electron injection. This work highlights the great potential of the stable and highly dispersed discrete metal chalcogenide clusters as high-efficiency photosensitizers for converting solar energy to chemical energy.