Using density functional theory with dispersion correction and U-parameter (DFT + U-D3) method, the Cu release process from spinel structure is simulated by stepwise removal of CuO from spinel-structured Cu16Al32O64, forming Cu16-nAl32O64-nwith CuO defects (VCuO)n (n = 1-8). The stepwise formation energies of the Cu16-nAl32O64-n exhibit a complex variation trend with the increasing n, revealing an initial decline from n = 1 to n = 4 and increase with n = 5-7 followed by sharp decrease at n = 8. Interestingly, the stepwise formation energies even become negative (-0.26 eV for n = 4 and-1.62 eV for n = 8, respectively). Hence, the total formation energies of the Cu16-nAl32O64-nsystem demonstrate an increasing trend with two energy reductions at n = 4 and n = 8, respectively. It was also found that the formation of CuO defect induced significant changes in the cationic coordination environment, leading to atomic rearrangement and lattice distortion. As the number of defects increases, the coordination number of some Al atoms decreases from hexa-coordination to lower-coordinations (primarily tetra-coordination, followed by penta-coordination and rarely tri-coordination). The findings of this study are consistent with the experimental data obtained during the sustained release catalysis, validating the dynamic changes in the surface structure during the catalytic process and laying a foundation for further research on the releasing mechanism of Cu-Al spinel.

Achieving high-performance deep-blue emitters continues to be a pivotal issue in organic light-emitting diode (OLED) research. Materials exhibiting hybridized local and charge-transfer (HLCT) excited states present a viable strategy, combining rapid radiative decay with effective harvesting of triplet excitons. This work presents a novel molecular design strategy through strong electron-accepting group modification at the C2 position of the phenanthroimidazole core. Two deep-blue emitters, PPIPEO and PPIIDO, incorporating phenylethanone and indanone units, respectively, were synthesized and systematically investigated. Photophysical investigations coupled with computational analyses verify the establishment of an HLCT state, distinguished by a high-lying reverse intersystem crossing (hRISC) channel from T4 to S1 configurations. The substantial energy separation between S1 and T1 excludes the operation of a thermally activated delayed fluorescence process. The compounds demonstrate robust thermal stability, with degradation temperatures above 450 degrees C. Devices configured with PPIPEO and PPIIDO in a non-doped architecture yielded peak EQEs of 5.61% and 5.05%, respectively, corresponding to exciton utilization efficiencies surpassing the spin-statistical limit of 25%. When doped into an mCP host, the devices exhibited stable deep-blue electroluminescence peaking around 440 nm and narrowed spectra, yielding chromaticity coordinates of (0.15, 0.08) for PPIIDO-based device, which nearly meets the standard blue chromaticity specified by NTSC, alongside considerable EQEs reaching 5.40%. This work not only demonstrates efficient deep-blue HLCT luminescent materials but also affirms that modification with electron-accepting groups at the C2 site represents a highly effective design paradigm.

A series of Ru/CeO2 catalysts were prepared using the deposition precipitation method, and then were fully characterized and evaluated in methanol steam reforming. The results indicated that, besides the target product H2, CH4 was also generated during methanol steam reforming (MSR). The selectivity towards CH4 was governed by reaction conditions (temperature/water-to-methanol ratio) as well as Ru loading. When the reaction temperature was below 320 degrees C, the CH4 selectivity was very low. However, when the temperature exceeded 340 degrees C, the CH4 selectivity increased and continued to rise with the increase of temperature. The influence of the molar ratio of water to methanol was comparatively complex. At a water-to-methanol molar ratio below 1.0, the CH4 selectivity was very low; however, exceeding the ratio above 1.0 resulted in an increase in the CH4 selectivity. Furthermore, an increase in Ru content promotes the formation of non-solid solution Ru species, thereby enhancing CH4 selectivity. Further investigation revealed that CH4 was not formed through the direct transformation of CH3OH, but was rather generated from reaction intermediates with the participation of water. Given that an optimal molar ratio exists for H2 formation, the mechanism by which water participates in the reaction was extremely complex. Based on the research results, the 0.5%Ru/CeO2 catalyst was identified as the optimal choice, showing the highest specific activity. Under a high weight hourly space velocity (WHSV) of 6 h-1, a reaction temperature ranging from 300 to 380 degrees C, and a water-to-methanol molar ratio from 0.96 to 1.2, higher H2 selectivity was obtained.

An increase in copper ion content and the simultaneous decrease in hydrogen sulfide (H2S) are the important factors causing Alzheimer's disease. Therefore, it is necessary to develop a simultaneous, sensitive, and rapid method for detecting sulfide ions (S2-) and copper ion (Cu2+) in biological systems. In this study, a colorimetric method for detecting sulfide ions using a composite of ferric alpha-iron oxide and zeolitic imidazolate framework-67, namely alpha-Fe2O3/ZIF-67, was developed. alpha-Fe2O3/ZIF-67 with peroxidase (POD)-like activity was synthesized by hydrothermal methods using the alpha-Fe2O3-ZIF-67 composite. In the presence of H2O2, this prepared nanozyme catalyzed the oxidation of 3,3 ',5,5 '-tetramethylbenzidine to generate a blue oxidation product. In the presence of H2S, the active sites of alpha-Fe2O3/ZIF-67 combined with it, and the POD-like activity was inhibited, resulting in the disappearance of the blue color. This method achieved the colorimetric detection of S2- at 652 nm with a linear range of 0.4-128 mu M and a detection limit of 0.27 mu M. Furthermore, Cu2+ were simultaneously detected by colorimetry due to the restoration of the nanozyme via strong bonding of Cu2+ and S2-. This platform has been successfully applied to the detection of S2- in human serum.

Addressing the dynamic behavior of carrier extraction and the regulation of the metal d-band center is crucial yet remains a significant challenge in the photocatalytic water-splitting process. In this study, we successfully incorporated different amounts of Pd into the ZnIn2S4 lattice using a one-pot oil bath method. This approach facilitated efficient carrier extraction and effective modulation of the d-band center by introducing numerous Sdefect sites. Furthermore, the coupling of 2.79 wt% Pd optimized the adsorption free energy of ZnIn2S4 for the crucial hydrogen evolution intermediate (*H). As a result, the solar efficiency, specific surface area, hydrophilicity, and carrier separation efficiency of ZnIn2S4 were all enhanced. Illuminated by a 300 W xenon lamp, the photocatalytic hydrogen evolution rate achieved 2.31 mmol/g/h, exhibiting a quantum efficiency of 4.56 % at 420 nm. These findings contribute to overcoming the dynamic bottlenecks in photocatalytic water splitting, thus enhancing the efficiency of solar energy conversion into clean energy sources.

The efficient conversion of waste to renewable energy via photocatalysis is critically limited by sluggish carrier dynamics (separation and transfer), leading to severe charge recombination and diminished performance. Herein, we demonstrate a Co-N bond engineered photocatalyst that enables fast carrier extraction and transfer by anchoring Co3O4 nanoparticles onto g-C3N4, addressing the intrinsic kinetic bottleneck in photocatalytic waste-to-energy systems. The experimental results demonstrated that the introduction of Co3O4 nanoparticles enhanced the number of active sites and the solar light response range of g-C3N4. Moreover, the directional charge transfer driven by the Schottky barrier significantly increased the number of effective charges. As a result, the hybrid catalyst exhibits excellent bifunctional catalytic performance in synchronous hydrogen production (3863.2 mu mol/h/g) and tetracycline (TC) degradation, which is 10 times higher than pure g-C3N4. This study provides theoretical and experimental references for designing multifunctional photocatalytic systems based on interface regulation and has reference significance for the development of environmental remediation and energy conversion synergistic technologies.

A unified strategy to generate acyl radicals from α-imino-oxy acids via selective C-C bond activation is reported. In the presence of a silver catalyst, α-imino-oxy acids could undergo decarboxylation and N-O and C-C bond homolysis to deliver the acyl radicals, which were subsequently captured by N-alkyl-N-aryl-2-(trifluoromethyl)acrylamides to access acylated 3-CF3-2-oxindoles.

A series of surface-modified Cu1−xLaxAl2.5 spinel catalysts with La were prepared by using the impregnation method and used in the methanol steam reforming (MSR) for hydrogen production. The interaction between La and the spinel catalyst, along with its effect on the sustained release of copper species, was investigated with the help of XRD, N2 sorption, H2-TPR, and XPS characterization techniques. The results indicate that La modification not only alters the microenvironment of Cu species and enhances the oxygen adsorption, but also promotes the formation of Al–O–La bonds, resulting in a stable interfacial structure. The Cu1−xLaxAl2.5 spinel catalysts can be applied to the MSR reaction without pre-reduction treatment. Under 260 ℃, a water-to-alcohol molar ratio of 2, and a methanol mass space velocity of 2.0 h−1, the optimal catalyst Cu0.9La0.1Al2.5 maintains a stable methanol conversion of approximately 94% during a continuous reaction lasting for 136 h. In comparison with the unmodified catalyst, the catalytic activity of Cu0.9La0.1Al2.5 is 5% higher, in addition to a decreased selectivity to CO by 20%. Further studies reveal that the Cu0.9La0.1Al2.5 catalyst has the lowest Cu sustained release rate and the minimal Cu grain size after prolonged reaction, indicating that La modification plays a crucial role in determining the sustained release rate and the fate of the Cu species.

A series of CuO/CeO2 catalysts with different Cu contents (2 wt %, 1, 0.75, and 0.5 wt %) were prepared by the impregnation method and were characterized by various techniques such as X-ray diffraction, N2-adsorption/desorption, H2-TPR, Raman spectroscopy, and X-ray photoelectron spectroscopy. Moreover, their catalytic performance in CO oxidation was evaluated under both dry and wet conditions. In the absence of water, the T 100 value decreased with Cu contents ranging from 0.5% to 0.75% and then leveled off from 0.75% to 2.0 wt %. However, a different variation trend emerged upon water addition. In the presence of water, the catalyst with 0.75-1.0 wt % Cu exhibited the highest catalytic activity, showing the lowest T 100. These results indicated that excessive Cu was detrimental to CO oxidation under wet conditions but served as a spectator under dry conditions. To explore the possible mechanism, the DFT + U method was employed to investigate the adsorption of water molecules on different systems, including Cu-doped and undoped CeO2. Compared with CeO2 and CeO2-x , Cu-doped systems manifested a greater propensity for adsorbing water molecules, with the potential formation of two hydroxyl groups. It was found that the subsequent CO adsorption could interact with some of the surface lattice oxygens to form CO2, but the absolute value of formation energy was lower as compared to the pure Cu/CeO2(111) surface. The results could be used to account for the negative effect of water on the catalytic oxidation of CO. However, when CO is adsorbed onto the hydroxyl O atom, a formate-like species is formed. As expected, the formate-like species could be decomposed to generate CO2, thereby demonstrating a promoting effect of water, which was evidenced by additional catalytic testing at a high-temperature of 360 degrees C over the 0.75 CuCe catalyst. However, the water promoting effect was not found with the 2CuCe catalyst, demonstrating an obvious loading effect. This article provides foundational data that can be referenced for further research.

An in situ confinement polymerization technology was developed to construct nitrogen-doped carbon tubes (NCT) with a uniform distribution of silver nanoclusters (AgNCs). Specifically, polydopamine (PDA) was utilized as a good stabilizer and carbon precursor by using curcumin as a template to induce the self-polymerization of dopamine in the presence of Ag+. Then, the AgNC@NCT materials were formed by template removal and subsequent carbonization. The prepared AgNC@NCT materials exhibited excellent stability, catalytic activity, and electrochemical properties due to their high carbonization and silver content. The AgNC@NCT-modified electrode had strong catalytic oxidation activity, specific surface area, and charge transfer efficiency for the detection of d-tryptophan (d-Trp). The constructed electrochemical sensor demonstrated a good linear range (0.1-100 mu M) with a low detection limit (0.009 mu M) for d-Trp detection. The sensor also had excellent selectivity, high stability, and repeatability. More importantly, it could be used for the evaluation of d-Trp levels in human serum with high accuracy. This method provided a strategy for the detection of d-Trp in biological samples, which had a good application prospect in daily clinical tests.

A completely new type of nitrogen-doped polymer nanosphere and the derived nitrogen-doped porous carbon nanospheres were produced by taking 2,4-diamino-6-hydroxypyrimidine as the precursor. When functioning as electrode materials, they demonstrated extraordinary electrochemical performance, offering a powerful candidate for supercapacitors.

Combining photocatalytic nitrogen fixation with antibiotic wastewater degradation reaction is of great significance. As a metal-free photocatalyst, g-C3N4 has great application prospect in the field of bifunctional photocatalytic reaction because of its abundant raw materials, simple preparation method, low toxicity, and high stability. However, the further development of g-C3N4 is limited by its wide band gap (2.7 eV) and high recombination rate of carriers. In this paper, AgInS2 nanospheres modified g-C3N4 nanosheets were successfully prepared by a simple hydrothermal method. The photocatalytic nitrogen fixation activity of the obtained AgInS2-g-C3N4 hybrid was nearly two times (91 μmol/h/g) higher than that of g-C3N4. In addition, by adding a proper amount of tetracycline pollutant into the photocatalytic system, the photocatalytic nitrogen fixation activity was further increased to 248 μmol/h/g, and the synergistic degradation of tetracycline environmental pollutants was realized. Through a series of experimental characterization and theoretical calculation, the morphology and carrier dynamics of photocatalyst were systematically explored. The results show that the introduction of AgInS2 nanospheres improves the utilization rate of sunlight, surface active sites and carrier transport rate of g-C3N4. This work provides references for the design of environmentally friendly photocatalysts and their applications in the fields of environmental purification and energy conversion.

The different metal decorated Cu/CeO 2 catalysts was synthesized by immersion method, and it was found that the formation of Cu/M–O–Ce solid solutions and more Ce 3+ and oxygen vacancies on the surface favored the improvement of catalytic performance.

A series of Cu0.1-xNixCe0.9O2-y catalysts with different Cu/Ni molar ratios were prepared by the ball milling method. The obtained catalytic materials were characterized by XRD, H2- TPR, BET, XPS and Ramen and the effects of different Cu/Ni content on the structure, properties and CO catalytic oxidation performance of the catalysts were explored. The results evidenced the formation of Cu-Ni-Ce mixed oxide solid solution in all ternary catalysts. In addition, there is a synergistic interaction between Cu and Ni in ternary cat-alysts, resulting in more oxygen vacancies and improved reduction performance, and hence demonstrating better CO catalytic oxidation activity in the ternary catalysts than binary ones. Under a GHSV of 60000 mL.gcat -1 .h-1, the required reaction temperature for reaching less than 10 ppm CO is lowed from 160 degrees C with Cu0.1Ce0.9O2-y to 130 degrees C with Cu0.07Ni0.03Ce0.9O2-y. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

A series of xMnCu/Ce catalysts with constant low Cu loading of 1 wt% were prepared by the simple impregnation method. The obtained catalysts were characterized by XRD, BET, H2- TPR and XPS, and the preferential oxidation of CO was evaluated in CO2/H2-rich atmo-spheres. It was shown that partial Mn and Cu could be incorporated into the Ceria lattice, forming surface ternary Cu-Mn-Ce oxide solid solutions. At Mn/Cu = 0.6, the catalyst presented strong interaction among Cu, Mn and Ce, had more Ce3+ and Mn4+ at the surface and showed the best catalytic performance, making CO conversion increase of 23.57% at 90 & DEG;C as compared with the Cu/Ce catalyst. For CO-Prox, the highest CO conversion was 94.7% with an oxidation selectivity of 78.9% at 125 & DEG;C. At this temperature, the catalyst revealed stable catalytic performance for a total TOS of 205 h. In addition, with CO/Ar as feed gas, CO conversion was 100%, confirming the negative effects of CO2/H2.& COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

The adsorption of O2 on Cu/CeO2(111) and the CO oxidation reactivity of the formed oxygen species were studied using the DFT method. The results showed that superoxide species (O2δ-), which directly interacted with Cu, formed when O2 adsorbed on the surface oxygen vacancies, while O2 adsorbed on the subsurface oxygen vacancies gave rise to ozone-like O3δ- species by combining with the nearest surface lattice oxygen (O1). PDOS showed that hybridization of the 2p orbitals between O2 and O1 formed a delocalized π bond, confirming the formation of O3δ-. For O2δ-, electrons on Cu and O1 transferred to O2 while the charge of Ce remained unchanged. However, for O3δ-, the transferred electrons were mainly from O1, and partially from O2, Ce1 and Ce2. It was very interesting that Cu also received a few electrons in the latter case. Compared with CO directly adsorbed on lattice oxygen, the two oxygen species were active for CO oxidation, forming CO2 or carbonates, and higher absolute adsorption energy was obtained with the interaction between CO and O3δ-. The findings of this study provide new insight on the CO oxidation reaction mechanism, facilitating an in-depth understanding of Cu-doped CeO2 catalysts.

Utilizing 1,3,4-oxadiazole amide that possesses outstanding electron mobility to serve as auxiliary ligands, four novel iridium (III) complexes of Ir1-Ir4 were prepared. Their structure, photophysical, and electrochemical characteristics were examined in detail, and quantum chemical calculations were used to interpret their photophysical behaviors. At room temperature, complexes Ir1 and Ir2 exhibit almost coincident green phosphorescence with peaks at 506 nm. Ir3 and Ir4 complexes produce greenish blue and greenish yellow light with a double-peak structure located at 496 and 531 nm. Organic light-emitting diodes utilizing Ir1-Ir4 as emitters exert extremely moderate efficiency roll-off, which is caused by the emitters bearing CF3-substituted 1,3,4-oxadiazole amide possessing excellent electron mobility.

采用水热合成法制备了SiO2-CeO2载体,并利用浸渍法负载活性组分CuO得到CuO-SiO2-CeO2催化剂.通过XRD、BET和H2-TPR等手段对载体和催化剂进行表征及性能测试,最后探究了SiO2摩尔分数对催化剂的比表面积以及甲醇水蒸气重整制氢实验中催化性能的影响.研究发现,适量添加SiO2可以增加载体和催化剂的比表面积,降低催化剂活性组分CuO的还原温度,提高CH3OH的转化率.当SiO2摩尔分数为2.5％时,催化剂CuO5.0％-SiO22.5％-CeO2的比表面积为112.8 m2/g,CH3OH转化率为75.1％.继续提高催化剂中SiO2的摩尔分数,催化剂的比表面积减小,CH3OH转化率降低.