Byskovrutledge4437

Sulfation inhibited the adsorption of NOx on the α-Fe2O3 catalyst surface and reduced the thermal stability of nitrates at medium-high temperature. Thus, the Langmuir-Hinshelwood (L-H) mechanism was inhibited, and the reaction mainly followed the Eley-Rideal (E-R) mechanism.Improving the selectivity of photocatalysis and reducing the generation of toxic by-products are the two key challenges for the development of highly efficient and stable photocatalysts. In this work, it was revealed that Zn-Ti-layered double hydroxide (ZT-LDH) photocatalyst, which generated less intermediates, showed better toluene degradation efficiency (removal ratio, 75.2%) and stability, compared with P25 (removal ratio, 10.9%). During the photocatalytic toluene degradation, benzaldehyde and benzoic acid were the main intermediates existed in the gas phase and on the surface of the catalyst, respectively. By combining experiments with theoretical calculation, it was found that the hydrogen atoms on the hydroxyl groups in the LDH would selectively attract the oxygen atoms in the carbon-oxygen double bond of the two major intermediates, facilitating their adsorption and activation on ZT-LDH. Besides, the surface electronic structure of ZT-LDH was demonstrated to facilitate the ring-opening reaction of the two major intermediates, eventually maintaining high activity and stability. This work could provide new molecular perspectives for understanding the photocatalytic reactions in VOCs degradation and developing efficient and stable photocatalysts.The right choice of synthesis route for upconverting nanoparticles (UCNPs) is crucial for obtaining a well-defined product with a specific application capability. Thus we decided to compare the physicochemical, cytotoxic, and temperature-sensing properties of UCNPs obtained from different rare earth (RE) ions, which has been made for the first time in a single study. The core/shell NaYF4Yb3+,Er3+/NaYF4 UCNPs were obtained by reaction in a mixture of oleic acid and octadecene, and their highly stable water colloids were prepared using the ligand-free modification method. Both oleate-capped and ligand-free UCNPs exhibited a bright upconversion emission upon 975 nm excitation. Moreover, slope values, emission quantum yields, and luminescence lifetimes confirmed an effective energy transfer between the Yb3+ and Er3+ ions. Additionally, the water colloids of the UCNPs showed temperature-sensing properties with a good thermal sensitivity level, higher than 1 % K-1 at 358 K. Evaluation of the cytotoxicity profiles of the obtained products indicated that cell viability was decreased in a dose-dependent manner in the analyzed concentration range.Utilizing the synergistic effect of multiple components in heterostructured composites has been regarded as a promising strategy for achieving high-performance electromagnetic wave absorption. Nonetheless, rationally collocate the components of absorbers in order to legitimately achieve synergy remains an intractable problem. By adjusting the NiS and ZnS composition ratios in the ZnS/NiS/C composites, the optimal impedance matching and dissipation capability can be obtained. The formation of a ZnS/NiS heterostructure is found to significantly enhance polarization relaxation, and the relative ratios of ZnS and NiS have a significant effect on the electromagnetic properties. The optimal performance was obtained on Z1N2, with a minimum reflection loss of -51.45 dB at 4.72 GHz and -56.69 dB at 11.12 GHz, respectively, and an effective absorption bandwidth of up to 3.68 GHz at 1.16 mm. The potential of heterogeneous bimetal sulfides as high-performance absorbers is demonstrated in this study.As an antioxidant, hindered phenol scavenges free radicals. Due to the oxidative degradation of black phosphorus (BP) in the presence of water and oxygen, free radical quenching of hindered phenol antioxidants can solve this issue and improve the environmental stability and flame retardant efficiency of BP. Herein, hydroxyl-modified BP (BP-OH) with active groups on the surface was obtained by hydroxylation, and then the hindered phenol antioxidant was grafted onto the surface of BP-OH through an isophorone diisocyanate bridging covalent reaction to obtain hindered phenol-modified BP (BP-HPL). The fire hazard of thermoplastic polyurethane (TPU) can be significantly reduced by introducing BP-HPL into TPU. Adding 2 wt% BP-HPL can reduce the heat release rate and total heat release values of TPU by 49.9% and 49.0%, respectively. In addition, the reductions in smoke volume and carbon monoxide production were also significant. find more Compared with BP-OH, the environmental stability of BP-HPL is significantly improved. This work provides a reference for the application of BP in the field of fire safety and simultaneously achieves the improvement of the environmental stability and flame retardant performance of BP.The mechanism leading to the extraordinary stability of bulk nanobubbles in aqueous solutions remains an outstanding problem in soft matter, modern surface science, and physical chemistry science. In this work, the stability of bulk nanobubbles in electrolyte solutions under different pH levels and ionic strengths is studied. Nanobubbles are generated via the technique of ultrasonic cavitation, and characterized for size, number concentration and zeta potential under ambient conditions. Experimental results show that nanobubbles can survive in both acidic and basic solutions with pH values far away from the isoelectric point. We attribute the enhanced stability with increasing acidity or alkalinity of the aqueous solutions to the effective accumulation of net charges, regardless of their sign. The kinetic stability of the nanobubbles in various aqueous solutions is evaluated within the classic DLVO framework. Further, by combining a modified Poisson-Boltzmann equation with a modified Langmuir adsorption model, we describe a simple model that captures the influence of ion species and bulk concentration and reproduce the dependence of the nanobubble's surface potential on pH. We also discuss the apparent contradiction between quantitative calculation by ion stabilization model and experimental results. This essentially requires insight into the structure and dynamics of interfacial water on the atomic-scale.The electrocatalytic reduction of nitrogen (N2) to ammonia (NH3) has broad prospects for green and sustainable NH3 production. Due to the electrocatalytic nitrogen reduction reaction (eNRR) performance of transition metal compound may be restricted with low yield rate, we develop transition metal interface engineering to improve the eNRR performance. Although the edge of MoS2 catalyst is active, the MoS2(001) surface is inert for N2 electroreduction. Through the hydrothermal and electrodeposition methods, Fe(OH)3 as N2 and H+ channels coated on MoS2 nanosheets array (MoS2@Fe(OH)3/CC) is synthesized. Such catalyst exhibits excellent eNRR performance in 0.1 M Na2SO4 with high Faradaic efficiency (2.76%) and NH3 yield rate (4.23 × 10-10 mol s-1 cm-2) at - 0.45 V (vs. RHE). This work may provide a new electrocatalyst synthesis pathway for artificial N2 fixation. Density functional theory calculations show that electrodeposition Fe(OH)3 can accelerate eNRR process rate of MoS2.In this paper, a new hexagonal prismatic Zn-MOF is rapidly synthesized at room temperature through a one-step precipitation method as precursor for the preparation of porous carbon. The SEM and GCD tests indicate that the pre-ionization process of BTC greatly accelerates the reaction speed between BTC and Zn ions, and only 0.5 h is required for the preparation of Zn-MOF with orderly morphology at room temperature, far less than 3-24 h of the existing hydrothermal synthesis. The derived porous carbon (BTCC) is provided with a considerable specific surface area of 1,464 m2 g-1 and suitable pores of 3.9 nm in size. Its richly porous structure offers a superior supercapacitor performance. The BTCC electrode offered a high specific capacitance and an excellent cycle stability. Furthermore, the assembled two symmetrical supercapacitors, C|1 M Na2SO4|C and C|6 M KOH|C, provide high energy density of 22.4 Wh kg-1 and 13.7 Wh kg-1, respectively. Their energy retention rates were 80.0% and 89.4%, respectively after 10,000 cycles at 20 A g-1. The proposed pre-ionization strategy is a facile, convenient and easy-to-industrial method for the preparation of new MOFs, thereby significantly reducing the manufacturing cost of porous carbon for energy storage.Pseudocapacitive materials based on multi-active components are attractive platforms for future portable energy devices due to their excellent redox processes and low cost. In this study, nanostructured bismuth-iron chalcogenide anchored on multiwalled carbon nanotube framework (Bi-Fe chalcogenide/C)-based electrode materials were fabricated via a simple solvothermal protocol with enhanced electrochemical performances. The obtained Bi-Fe chalcogenide/C nanocomposites combining the improved electroconductivity of carbonic frameworks and high pseudocapacitive properties of Bi/Fe reversible redox processes were employed as negative electrodes for asymmetric supercapacitor (ASC) devices. Systematic investigation of the synthesized materials and capacitive performance indicated that the Bi-Fe-P/C electrode simultaneously achieved an intrinsically appreciable specific capacitance of 532 F g-1 at a current density of 1 A g-1, high-rate capability, and cyclic stability, profiting from the structural and amorphous mertion for enhancing the electrochemical performance of ASC.Covalent organic frameworks (COFs) are a new class of porous materials receiving much attention due to their unique characteristics. However, COFs have been usually synthesized under harsh and complicated conditions, limiting their practical applications. We propose a surfactant-free strategy to controllably synthesize an imine-based covalent organic framework (COF) nanomaterial in water at room temperature. Introduction of tiny amounts of co-solvents not only achieves the morphology and size control of COFs but also ensures stability of COF nanomaterials in aqueous solution. Moreover, water as a solvent plays an important role in the size adjustment of COFs. The surface area of the obtained COFs was approximately 398 m2/g with a pore size distribution of about 2.8 nm. In addition, the COFs displayed a good crystallinity.Recently, aqueous rechargeable batteries employing ammonium-ions (NH4+) as charge carriers have received increasing interest because of their merits of eco-friendly, low cost and sustainability. However, the supercapacitor based on NH4+ charge carriers has rarely been reported probably owing to the lack of a suitable system to achieve acceptable capacitance and cycle performance for NH4+ storage. Herein, we develop a dual-polymer strategy to boost the electrochemical properties of hydrated vanadium oxide (HVO) for outstanding NH4+ storages based on a supercapacitor. One polymer polyaniline (PANI) is intercalated into the interlayer space of HVO (11.0 Å) to synthesize PANI-intercalation-HVO (PVO) with the expanded interlamellar spacing of 13.9 Å, which enhances the kinetics and stabilizes the structure during the NH4+ (de)intercalation. The capacitance at 1 A·g-1 is significantly improved from 156F·g-1 (HVO) to 351F·g-1 (PVO). The other polymer polyvinyl alcohol (PVA) is used to get the quasi-solid-state (QSS) PVA/NH4Cl electrolyte, in which the cycle stability of PVO electrode is effectively improved.