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The energy dissipation pathways of a photosensitizer for phototherapies, including photodynamic therapy (PDT) and photothermal therapy (PTT), compete directly with that of its fluorescence (FL) emission. Enriching heavy atoms on the π‐conjugated systems and aggregation‐caused quenching are two effective methods to turn off the FL emission of photosensitizers, which is expected to boost the intersystem crossing (for PDT) and nonradiative transition (for PTT) of photosensitizers for maximized phototherapeutic efficacy. Following this approach, an all‐iodine‐substituted polydiacetylene aggregate poly(diiododiacetylene) (PIDA) has been developed, which shows a superior near infrared absorption (ε808nm = 26.1 g−1 cm−1 L) with completely blocked FL, as well as high efficiency of reactive oxygen species generation (nearly 45 folds of indocyanine green) and photothermal conversion (33.4%). To make the insoluble fibrillar PIDA aggregates favorable for systemic administration, they are converted into nanospheres through a pre‐polymerization morphology transformation strategy. The in vivo study on a 4T1 tumor‐bearing mouse model demonstrates that PIDA nanospheres can almost eliminate the tumor entirely in 16 days and prolong the survival time of mice to over 60 days, validating their effective phototherapeutic response through the strategy of inhibiting FL for boosted intersystem crossing and nonradiative transition. [ABSTRACT FROM AUTHOR]

Layered double hydroxide (LDH) nanostructures are commonly used to study the interfacial effects of Pt‐based catalysts in CO oxidation. However, the specific role and detailed intermediates involved in CO oxidation remain unclear. Density functional theory (DFT) predicted that NiFe LDH loaded with single Pt atoms would exhibit satisfactory CO oxidation activity. On this basis, we prepared Pt1NiFe LDH catalysts with various Fe : Ni ratios by using the one‐pot method and achieved favorable dispersion of single Pt atoms. Pt1/FN‐1, which had the optimal Fe : Ni ratio (1 : 1), exhibited satisfactory catalytic performance for CO oxidation and a high turnover frequency, as determined through DFT calculations and experimental characterization. In‐situ diffuse reflectance infrared Fourier transform spectroscopy confirmed that CO directly reacted with Pt1/FN‐1 to produce CO2 and that introduced O2 formed bicarbonate species to produce CO2 together with the adsorbed CO on Pt1 sites. Overall, our work provides new insights into the catalytic mechanism of the well‐known Pt1NiFe LDH catalysts in CO oxidation. [ABSTRACT FROM AUTHOR]

Polydiacetylenes, as a class of conjugated polymers with alternating conjugated C═C and C≡C bonds, have emerged as a promising probe material for biomedical Raman imaging, given their ultrastrong Raman scattering intensity. However, the relationship between the structure, especially the molecular length of polydiacetylenes, and their Raman scattering intensity remains unclear. In this work, a series of water‐soluble polydiacetylenes, namely poly(deca‐4,6‐diynedioic acid) (PDDA) with different molecular weights (MWs), is prepared through controlled polymerization and degradation. The ultraviolet–visible (UV–vis) absorption spectroscopic and Raman spectroscopic studies on these polymers reveal that the Raman scattering intensity of PDDA increases nonlinearly with the MW. The MW‐Raman scattering intensity relationship in the polymerization process is completely different from that in the degradation process. In contrast, the Raman scattering intensity increases more linearly with the maximal absorbance of the polymer, and the relationship between the Raman scattering intensity and the maximal absorbance of PDDA in the polymerization process is consistent with that in the degradation process. The Raman scattering intensity of PDDA hence exhibits a better dependence on the effective conjugation length of the polymer, which should guide the future design of conjugated polymers for Raman imaging applications. [ABSTRACT FROM AUTHOR]

The volume fraction, dissolution, and segregation of WC particles in metal-matrix composites (MMCs) are critical to their wear resistance. Low carbon steel substrates were precoated with NiCrBSi coatings and processed with gas tungsten arc melt injection method to fabricate MMCs with high volume fraction of WC particles. The microstructures and wear resistance of the composites were investigated. The results showed that the volume fraction of WC particles increased with decreasing hopper height and was as high as 44% when hopper height was 100 mm. The dissolution of WC particles was minimal. The content of the alloying elements decreased from the top to the bottom of the matrix. More WC particles dissolved in the overlapping area, where Fe3W3C carbide blocks could be found. The wear loss of the MMCs after 40 min was 6.9 mg, which is 76 times less than that of the substrate after the 4 min test.

The disordered arrangement and thereof inferior conductivity of 2D MOF sheets seriously hinder their practical application. Herein, we propose in situ transformation strategy to architect vertically oriented bimetallic CuNi-MOF as a self-supporting electrode, leading to a decuple high specific capacitance of 1262 C g-1 in comparison with the pristine Ni-MOF powder of 114 C g-1 at 2 A g-1. DFT calculations reveal that introduction of Cu can modulate the electronic structure of metal centers in the Ni-MOF sheets and optimize electrical conductivity. Our strategy is promising to maximize the utilization of MOF superiorities for optimizing their electrochemical performance. We provide an in situ transformation strategy for synthesizing high-activity oriented bimetallic MOFs derived from vertically oriented Cu(OH)2 nanowires, with which an order of magnitude of performance-improved electrodes were produced for pseudocapacitance. [ABSTRACT FROM AUTHOR]

Industrial activities discharge heavy metal-laden wastes; and copper is one of these metals that can be stabilized after ceramic sintering by Al- or Fe-containing precursors. Besides traditional precursors, Al- and Fe-containing solid wastes (e.g., sewage sludge incineration ash, coal fly ash) were found equally capable of copper stabilization when they were adopted in the reaction matrices. However, the effect of CaO and SiO2, the predominant components in most of the inorganic solid wastes, on metal transformation and stabilization has not been addressed. Therefore, a CaO-SiO2-CuO-Al2O3-Fe2O3 reaction matrix was proposed in this study, focusing on the effect of CaO and SiO2 on copper transformation and immobilization. Results showed that a single-phase CuAlxFe2-xO4 spinel solution was developed in the system without CaO and SiO2, whereas the addition of CaO led to the generation of two separate spinel phases: CuAl2O4 and CuFe2O4. Compared with CaO, the existence of SiO2 showed less impact on the phase transformation. The effect of sintering temperature and additive dosage was also illustrated in this study and the results provided useful guidance for the optimization of reaction systems to achieve beneficial utilization of solid wastes for heavy metal stabilization. [ABSTRACT FROM AUTHOR]