Inexpensive and versatile electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) remain essential for the progress of rechargeable zinc-air batteries (ZABs) and comprehensive water splitting, though their development is challenging. The re-growth of secondary zeolitic imidazole frameworks (ZIFs) on ZIF-8-derived ZnO and subsequent carbonization treatment results in the formation of a rambutan-like trifunctional electrocatalyst. The Co-NCNT@NHC catalyst arises from N-enriched hollow carbon (NHC) polyhedrons that are grafted with N-doped carbon nanotubes (NCNTs) which in turn contain Co nanoparticles (NPs). The trifunctional catalytic activity of Co-NCNT@NHC is a consequence of the cooperative action of the N-doped carbon matrix and Co nanoparticles. The Co-NCNT@NHC catalyst, when used in alkaline electrolytes, displays a half-wave potential of 0.88 volts (vs. RHE) during oxygen reduction reaction (ORR), a 300 mV overpotential at 20 mA cm⁻² for oxygen evolution reaction (OER), and a 180 mV overpotential at 10 mA cm⁻² for hydrogen evolution reaction (HER). Impressively, two rechargeable ZABs in series provide power for a water electrolyzer, with Co-NCNT@NHC functioning as a singular, integrated electrocatalyst. For the practical implementation of integrated energy systems, these findings encourage the rational development of high-performance and multifunctional electrocatalysts.
From natural gas, catalytic methane decomposition (CMD) has emerged as a compelling technology for the production, on a large scale, of hydrogen and carbon nanostructures. The CMD process, being mildly endothermic, suggests that applying concentrated renewable energy sources, like solar power, in a low-temperature environment could be a promising method for operating the CMD process. GSK-3 inhibitor A straightforward hydrothermal synthesis is employed to fabricate Ni/Al2O3-La2O3 yolk-shell catalysts, followed by photothermal CMD testing. By varying the amount of La added, we demonstrate control over the morphology of the resultant materials, the dispersion and reducibility of Ni nanoparticles, and the nature of the metal-support interactions. Essentially, the addition of a precise quantity of La (Ni/Al-20La) augmented H2 generation and catalyst stability, relative to the standard Ni/Al2O3 composition, also furthering the base-growth of carbon nanofibers. In addition, a novel photothermal effect within CMD is demonstrated, wherein 3 suns of light illumination at a constant bulk temperature of 500 degrees Celsius induced a reversible increase in the H2 yield of the catalyst by approximately twelve times compared to the dark reaction rate, coupled with a decrease in the apparent activation energy from 416 kJ/mol to 325 kJ/mol. At low temperatures, the undesirable CO co-production was further suppressed through light irradiation. Our investigation into photothermal catalysis underscores its effectiveness in CMD, illuminating the contributions of modifiers in augmenting methane activation sites on Al2O3-based catalysts.
The study reports a simple technique of anchoring dispersed cobalt nanoparticles within a SBA-16 mesoporous molecular sieve coating that is applied to a 3D-printed ceramic monolith, thereby forming a composite material (Co@SBA-16/ceramic). While potentially enhancing fluid flow and mass transfer, the monolithic ceramic carriers' designable versatile geometric channels were accompanied by a smaller surface area and porosity. The hydrothermal crystallization method was employed to coat the monolithic carriers with SBA-16 mesoporous molecular sieve, thereby increasing the surface area and promoting the incorporation of active metal sites onto the surface. The dispersed Co3O4 nanoparticles, in contrast to the conventional impregnation method (Co-AG@SBA-16/ceramic), were obtained by directly introducing Co salts into the prepared SBA-16 coating (that contained a template), subsequently undergoing conversion of the Co precursor and removal of the template following calcination. The promoted catalysts underwent rigorous characterization using X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, Brunauer-Emmett-Teller surface area, and X-ray photoelectron spectroscopy analyses. Co@SBA-16/ceramic catalysts demonstrated outstanding catalytic efficacy in the continuous removal of levofloxacin (LVF) within fixed bed reactor systems. Co/MC@NC-900 catalyst displayed a 78% degradation efficiency in 180 minutes, a performance far superior to that of Co-AG@SBA-16/ceramic (17%) and Co/ceramic (7%). Photocatalytic water disinfection The heightened catalytic activity and reusability of Co@SBA-16/ceramic were attributed to the more uniform distribution of the active site within the molecular sieve's structure. In terms of catalytic activity, reusability, and long-term stability, Co@SBA-16/ceramic-1 is significantly superior to Co-AG@SBA-16/ceramic. A 720-minute continuous reaction in a 2cm fixed-bed reactor led to a stable LVF removal efficiency of 55% for the Co@SBA-16/ceramic-1 system. Employing chemical quenching experiments, electron paramagnetic resonance spectroscopy, and liquid chromatography-mass spectrometry, the degradation mechanism and pathways of LVF were hypothesized. The continuous and efficient degradation of organic pollutants is facilitated by the novel PMS monolithic catalysts of this study.
Metal-organic frameworks exhibit great potential in heterogeneous catalysis applications related to sulfate radical (SO4-) based advanced oxidation. In contrast, the massing of powdered MOF crystal particles and the complex recovery process presents a substantial impediment to their large-scale, practical implementation. The development of eco-friendly and adaptable substrate-immobilized metal-organic frameworks is of paramount importance. A rattan-based catalytic filter, incorporating gravity-driven metal-organic frameworks, was engineered to degrade organic pollutants by activating PMS at high liquid throughput, taking advantage of the material's hierarchical pore structure. Leveraging rattan's water transportation as a model, ZIF-67 was grown in-situ and uniformly across the internal surface of the rattan channels, implemented via a continuous flow procedure. The vascular bundles of rattan featured intrinsically aligned microchannels, which, in turn, acted as reaction compartments for the immobilization and stabilization of ZIF-67. Importantly, the catalytic filter derived from rattan exhibited exceptional gravity-driven catalytic activity (up to 100% treatment efficiency for a water flux of 101736 liters per square meter per hour), remarkable recyclability, and persistent stability in the process of degrading organic pollutants. Ten consecutive cycles of treatment saw the ZIF-67@rattan material removing 6934% of the TOC, thereby upholding its stable capacity for mineralizing pollutants. The micro-channel's inhibitory action fostered interaction between active groups and contaminants, thus enhancing degradation efficiency and boosting composite stability. A catalytic filter for wastewater treatment, utilizing gravity and rattan, offers a practical and effective method for creating renewable and ongoing catalytic processes.
Dynamic and precise manipulation of multiple microscopic objects has consistently represented a significant technical obstacle within the fields of colloid assembly, tissue engineering, and organ regeneration. Pine tree derived biomass The core argument of this paper revolves around the idea that the precise modulation and parallel manipulation of the morphology of individual and multiple colloidal multimers is attainable via the customization of acoustic fields.
This paper details a method for manipulating colloidal multimers utilizing acoustic tweezers with bisymmetric coherent surface acoustic waves (SAWs). This contactless technique allows for precise morphology modulation of individual multimers and the creation of patterned arrays by shaping the acoustic field to specific desired distributions. Regulating coherent wave vector configurations and phase relations in real time allows for the rapid switching of multimer patterning arrays, morphology modulation of individual multimers, and controllable rotation.
Initial demonstration of this technology's capabilities involves eleven deterministic morphology switching patterns for a single hexamer and precise switching between three array modes. Beyond this, the method of assembling multimers, incorporating three unique width categories, and allowing for controllable rotations of individual multimers and arrays, was shown. This was demonstrated from 0 to 224 rpm (tetramers). Consequently, the reversible assembly and dynamic manipulation of particles and/or cells are enabled by this method, particularly in colloid synthesis.
This technology's capabilities are exemplified by our initial achievement of eleven deterministic morphology switching patterns for a single hexamer, enabling precise transitions between three array modes. Furthermore, the assembly of multimers, featuring three distinct width specifications and adjustable rotation of individual multimers and arrays, was showcased across a range of speeds from 0 to 224 rpm (tetramers). Consequently, this method facilitates the reversible assembly and dynamic manipulation of particles and/or cells within colloid synthesis applications.
Adenocarcinomas, forming approximately 95% of colorectal cancers (CRC), are commonly linked to the presence of adenomatous polyps (AP) in the colon. Colorectal cancer (CRC) progression and incidence are increasingly linked to the gut microbiota, yet the human digestive system harbors an enormous microbial population. To fully understand the spatial variation of microbes and their impact on colorectal cancer (CRC) progression, from adenomatous polyps (AP) to different stages, a holistic view that encompasses the simultaneous assessment of multiple niches throughout the gastrointestinal system is critical. Employing an integrated methodology, we pinpointed microbial and metabolic markers capable of distinguishing human colorectal cancer (CRC) from adenomas (AP) and varying Tumor Node Metastasis (TNM) stages.