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With advantages such as low cost, high stability, and ease of production, visible light photocatalytic C3N4 with a unique microscopic layered structure holds significant potential for development. However, its hydrogen production efficiency remains low due to the pronounced recombination of photo-generated charge carriers and limited surface reaction sites. Normally, the photocatalytic performance of C3N4 can be enhanced by loading noble metals with surface plasmon resonance. It is worth noting that the size of noble metal nanoparticles has a great influence on photocatalytic performance. In this study, accurate controlling of the size and distribution of Au nanoparticles was achieved on the surface of C3N4 by introducing amino groups to improve photocatalytic performance. Results show that uniformly distributed Au nanoparticles in the range of 2–6 nm can be obtained on C3N4 with a remarkable enhancement of hydrogen production efficiency, which is about 114 times the property of pure C3N4. The small-sized and uniformly distributed Au nanoparticles can provide more reaction sites and increase the separation of photo-generated charge carriers, in turn improving Au/NH3–C3N4 photocatalytic hydrogen release rate to 6.85 mmol g−1 h−1. This work offers a facile way to enhance photocatalytic performance by controlling the size of metal nanoparticles on C3N4 precisely. [ABSTRACT FROM AUTHOR]

Utilization of the near‐infrared (NIR) light in the solar spectrum is critical for efficiency improvement of photocatalytic H2 evolution. However, common semiconductors have low response to the NIR light and narrow bandgap semiconductors have inappropriate redox potentials. Here, the study presents a new dual‐functional up‐conversion strategy in one sensitizer for promoting photocatalytic hydrogen production reactions by converting NIR light to visible light and high‐energy electrons simultaneously, via photon‐photon conversion and photo‐electronic process, respectively. Using WO3:Yb,Er as the sensitizer and Zn0.5Cd0.5S as the hydrogen evolution reaction catalyst, a photocatalytic hydrogen release rate of 24.3 mmol g−1 h−1 under simulated solar‐light has been achieved without using any co‐catalyst. After loading Ni2P as a co‐catalyst, the photocatalytic hydrogen production performance can be further improved to 41.3 mmol g−1 h−1 at 10 °C and 93.3 mmol g−1 h−1 under non‐temperature‐controlled conditions, exceeding most photocatalysts. This work offers a new strategy to improve the NIR light utilization of the solar‐light for promoting photocatalytic hydrogen generation through synergistic photo‐optical, photo‐electronic, and photo‐thermal effects. [ABSTRACT FROM AUTHOR]

In this work, a V2AlC‐based saturable absorber (SA) was applied to a 2 μm band passively mode‐locked (PML) laser. The saturation intensity and modulation depth of the V2AlC‐based SA were detected by the I‐scan method, which were 225.05 MW/cm2 and 7.68%, respectively. In the PML mode, an average power of 2.12 W at 1939 nm and a pulse width of 1077 ps at 82.49 MHz were obtained from the Tm:YAP laser. In addition, the laser exhibited a good beam quality factor (M2) which was measured to be less than 1.2. These results will pave the way for the application of V2AlC‐based SA in ultrafast lasers. [ABSTRACT FROM AUTHOR]

A nano‐immunomodulator (R‐NPT NP) comprising a tumor microenvironment (TME) activable resiquimod (R848) and a π‐extended NIR‐absorbing naphthophenanthrolinetetraone (NPT) has been engineered for spatiotemporal controlled photothermal immunotherapy. R‐NPT NP demonstrated excellent photostability, while R848 promoted synergistic immunity as a toll‐like receptor 7/8 (TLR7/8) agonist. Upon accumulation at the tumor site, R‐NPT NP released R848 in response to redox metabolite glutathione (GSH), triggering dendritic cell (DC) activation. The photothermal effect endowed by R‐NPT NP can ablate tumors directly and trigger immunogenic cell death to augment immunity after photoirradiation. The synergistic effect of GSH‐liable TLR7/8 agonist and released immunogenic factors leads to a robust evocation of systematic immunity through promoted DC maturation and T cell infiltration. Thus, R‐NPT NP with photoirradiation achieved 99.3 % and 98.2 % growth inhibition against primary and distal tumors, respectively. [ABSTRACT FROM AUTHOR]

Cancer represents a persistent global health challenge, and the inherent limitations of chemotherapy are widely acknowledged. Notably, there is growing interest in multifunctional core–shell nanostructures as promising candidates for diverse biological applications. Herein, we have successfully devised a biocompatible zeolitic imidazolate framework-8 (ZIF-8) coated onto multicore Tellurium nanodots (TeNDs) nanocarrier (MOFs@TeNDs). These nanoplatforms displayed a consistent size distribution, an average diameter of 100 ± 10 nm, and consistent morphological features. Furthermore, TeNDs exhibit a strong photothermal response and produce reactive oxygen species (ROS) when subjected to near-infrared (NIR) radiation. Moreover, ZIF-8 has shown a significant loading capacity for the medication doxorubicin hydrochloride (DOX), and subsequent drug release is controlled by pH and NIR, both responding to stimuli. Notably, this nanosystem has demonstrated excellent performance within in vitro assay by reducing the challenges associated with conventional anticancer therapies while enhancing their therapeutic abilities, auguring auspicious prospects for translation into in vivo applications, thereby highlighting its potential as a pioneering therapeutic modality. [ABSTRACT FROM AUTHOR]

Single-atom catalysts show excellent catalytic performance because of their coordination environments and electronic configurations. However, controllable regulation of single-atom permutations still faces challenges. Herein, we demonstrate that a polarization electric field regulates single atom permutations and forms periodic one-dimensional Au single-atom arrays on ferroelectric Bi4Ti3O12 nanosheets. The Au single-atom arrays greatly lower the Gibbs free energy for CO2 conversion via Au-O=C=O-Au dual-site adsorption compared to that for Au-O=C=O single-site adsorption on Au isolated single atoms. Additionally, the Au single-atom arrays suppress the depolarization of Bi4Ti3O12, so it maintains a stronger driving force for separation and transfer of photogenerated charges. Thus, Bi4Ti3O12 with Au single-atom arrays exhibit an efficient CO production rate of 34.15 µmol·g−1·h−1, ∼18 times higher than that of pristine Bi4Ti3O12. More importantly, the polarization electric field proves to be a general tactic for the syntheses of one-dimensional Pt, Ag, Fe, Co and Ni single-atom arrays on the Bi4Ti3O12 surface. The authors report a study preparing single atom (M = Pt, Ag, Fe, Co, and Ni) arrays on Au/Bi4Ti3O12 nanosheets using electric field polarization techniques. Photocatalytic CO2 reduction is shown to proceed effectively over Au/Bi4Ti3O12. [ABSTRACT FROM AUTHOR]

The construction of interfacial electric field (IEF) in semiconductor heterojunction is of great significance in boosting photocatalytic hydrogen evolution through efficient separation of photogenerated charge‐carriers. However, the exploitation of IEF in type‐I heterojunction has not been proposed for designing photocatalysts. Herein, based on the density functional theory prediction, p‐SnS with different work functions modulated by Sn‐vacancy are compounded with n‐ZnIn2S4 containing S‐vacancy to form type‐I heterojunction. The optimized SnS/ZnIn2S4 photocatalyst without co‐catalysts exhibits an impressive hydrogen evolution rate of 22.75 mmol g−1 h−1, 6.23 times of ZnIn2S4. Systematic investigations reveal that the interfacial Sn‐S bond acts as a transport channel that accelerates the interface charge‐carriers transfer under the promotion of IEF originating from the significant Fermi level difference. A large difference in the surface photovoltage signal of SnS/ZnIn2S4 and ZnIn2S4 is achieved from effective photogenerated charge‐carriers separation by IEF. The new p‐n type‐I scheme of SnS/ZnIn2S4 induced by the interfacial mediation can separate the photogenerated charge‐carriers, and retain the highly reductive electrons of ZnIn2S4 for hydrogen evolution, overcoming the disadvantage of reduction potential decline in the typical type‐I scheme. This study will afford a new theoretical basis for the achievement of high‐efficiency photocatalytic hydrogen evolution through interface modulation. [ABSTRACT FROM AUTHOR]

The empirical envelope (EE) method based on the amplitude-modulation and frequency-modulation (AMFM) decomposition is effective for identifying the modal parameters of time-varying and weakly nonlinear systems. However, the identification accuracy of the EE method is sensitive to noises which often exist in vibration measurements of real structures. In this study, an improved empirical envelope (IEE) method is proposed to achieve robust modal parameter identification from noisy measurements. Specifically, the idea of sliding window threshold denoising is introduced to reduce the error in the instantaneous envelope induced by abnormal extreme points, and a moving average filter is utilized to reduce the error in the instantaneous frequency induced by high-frequency noises. Two numerical examples and an experimental example of a full-bridge aeroelastic model are analyzed to validate the accuracy of the IEE method and highlight the superiority of the IEE method relative to the original EE method. It is concluded that the IEE method is robust to measurement noises (the considered signal-to-noise ratios include 5–90 dB) and that the IEE method is more accurate than the EE method. Hence, the IEE method serves as a promising alternative for modal parameter identification of time-varying and weakly nonlinear systems. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) is gaining more and more attentions as a promising metal-free photocatalyst for H2 production. Nevertheless, from the perspective of practical applications, the photocatalytic performance over g-C3N4 in visible-light region needs a further improvement. In this work, C doping and C quantum dots (QDs) are co-integrated in g-C3N4 by a one-step thermal polymerization method to obtain an advanced C QDs/C doped g-C3N4 photocatalyst. The synergistic effects of C doping and C QDs modification promote the photocatalytic activity of g-C3N4 significantly. The optimal C QDs/C doped g-C3N4 exhibits a significant improvement on visible-light-driven photocatalytic hydrogen production (205 ÎĽ mol gâˆ'1 hâˆ'1) with an apparent quantum yield (AQE) at 420 nm reaching 1.24%, which is approximately nine-fold enhancement than that of pristine g-C3N4. The increased photocatalytic activity mainly benefits from the enhanced visible light absorption and carrier separation efficiency. This study may open a new perspective for the design and fabrication of C-modified g-C3N4 for photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

The localized surface plasmon resonances (LSPR) effect makes W18O49 an effective visible and near‐infrared (NIR) light antenna to realize full‐spectrum solar‐light driven photocatalysis, yet the precise origin remains elusive. Here, the LSPR originates from the localized electron confinement around lattice W5+–W5+ pairs in the unique structure of W18O49 by density‐functional theory calculation, which gives W18O49 a broad absorption ranging from visible to NIR region, independent of the particle shape and size is confirmed. This unique periodic LSPR simplifies the design of W18O49‐sensitized photocatalytic composite into enhancing the light absorbance of W18O49 and screening photocatalytic semiconductors with suitable energy band potentials. To this end, hierarchical‐structure W18O49 microflowers with high absorbance have been coated with ZnIn2S4 nanosheets to achieve cocatalyst‐free photocatalytic composite, which presents an outstanding H2 production rate of 902.57 µmol within 3 h under simulated solar‐light. Comprehensive characterizations, including ultrafast transient absorption spectroscopy, prove the injection of hot electrons from W18O49 to ZnIn2S4 and the increase of long‐lived active electrons. This work clarifies the LSPR origin of oxygen‐deficient semiconductors and paves the way for the search of broad‐spectrum active photocatalyst. [ABSTRACT FROM AUTHOR]