Study on the influence of active oxygen on the natural oxidation of arsenopyrite under different temperature conditions.

Arsenic (As), a toxic element, contaminates farmlands, rivers, and groundwater, posing severe environmental and health risks. Notably, As-containing materials in tailings are affected by temperature variations during long-term storage, and this considerably impact the oxidation and migration of elements in arsenopyrite.This study focused on arsenopyrite and investigated the process of its oxidative dissolution and release of arsenic under different temperature conditions by using in-situ XRD, in-situ XPS and electron paramagnetic resonance spectroscopy(EPR), The role of oxygen free radicals in the oxidation of arsenopyrite was elucidated.

Mechanism of arsenic release process from arsenopyrite chemical oxidation.

Oxidation of arsenopyrite is one of the main causes of arsenic pollution in the environment. This study, examind changes in the surface properties of arsenopyrite in the presence of oxygen. Furthermore, X-ray photoelectron spectroscopy, in situ Raman analysis, high-resolution transmission electron microscopy, and ab initio molecular dynamics were carried out on arsenopyrite, and the oxidation properties and processes of the arsenopyrite surface, along with the Fe/As/S oxidation processes, were analysed In situ-Raman spectroscopy data clearly showed that in the presence of oxygen, Fe ions were transformed into Fe ions on the surface of arsenopyrite at 207 cm, and the content of iron oxides on the surface of arsenopyrite increased significantly over time.

In situ construction of robust artificial solid-electrolyte interphase layer on lithium-metal anode by a facile one-step solution route.

Development of high energy density lithium-metal batteries (LMBs) is markedly hindered by the interfacial instability on lithium-metal anode side. Solid-electrolyte interphase (SEI) is a fundamental factor to regulate dendrite growth and enhance the stability of lithium-metal anodes. Here, trithiocyanuric acid, a triazine derivative with sulfhydryl groups, is used as an efficient promoter to favor the construction of a robust artificial SEI layer on the lithium metal surface, which greatly benefits the stability and efficiency of LMBs.

Oxophilic Ce single atoms-triggered active sites reverse for superior alkaline hydrogen evolution.

The state-of-the-art alkaline hydrogen evolution catalyst of united ruthenium single atoms and small ruthenium nanoparticles has sparked considerable research interest. However, it remains a serious problem that hydrogen evolution primarily proceeds on the less active ruthenium single atoms instead of the more efficient small ruthenium nanoparticles in the catalyst, hence largely falling short of its full activity potential. Here, we report that by combining highly oxophilic cerium single atoms and fully-exposed ruthenium nanoclusters on a nitrogen functionalized carbon support, the alkaline hydrogen evolution centers are facilely reversed to the more active ruthenium nanoclusters driven by the strong oxophilicity of cerium, which significantly improves the hydrogen evolution activity of the catalyst with its mass activity up to -10.

Synergistic Mechanism of Combined Inhibitors on the Selective Flotation of Arsenopyrite and Pyrite.

The selective action mechanism of sodium butyl xanthate (BX), ammonium salt (NH ), and sodium -nitrobenzoate (m-NBO) on pyrite and arsenopyrite was examined by experiments and quantum chemistry. The experiments show that under alkaline conditions, ammonium salt (NH ) and m-NBO can have a strong inhibitory effect on arsenopyrite. At pH 11, the recovery rate of arsenopyrite reduces to 16%.

Distinct Crystal-Facet-Dependent Behaviors for Single-Atom Palladium-On-Ceria Catalysts: Enhanced Stabilization and Catalytic Properties.

High-performance, fully atomically dispersed single-atom catalysts (SACs) are promising candidates for next-generation industrial catalysts. However, it remains a great challenge to avoid the aggregation of isolated atoms into nanoparticles during the preparation and application of SACs. Here, the evolution of Pd species is investigated on different crystal facets of CeO , and vastly different behaviors on the single-atomic dispersion of surface Pd atoms are surprisingly discovered.

Supported Pt Nanoparticles on Mesoporous Titania for Selective Hydrogenation of Phenylacetylene.

Semi-hydrogenation of alkynes to alkenes is one of the most important industrial reactions. However, it remains technically challenging to obtain high alkene selectivity especially at a high alkyne conversion because of kinetically favorable over hydrogenation. In this contribution, we show that supported ultrasmall Pt nanoparticles (2.

Topological self-template directed synthesis of multi-shelled intermetallic NiGa hollow microspheres for the selective hydrogenation of alkyne.

Multi-shelled hollow structured materials featuring large void volumes and high specific surface areas are very promising for a variety of applications. However, controllable synthesis of multi-shelled hollow structured intermetallic compounds remains a formidable challenge due to the high annealing temperature commonly required for the formation of intermetallic phases. Here, a topological self-template strategy was developed to solve this problem.

MOF-Confined Sub-2 nm Atomically Ordered Intermetallic PdZn Nanoparticles as High-Performance Catalysts for Selective Hydrogenation of Acetylene.

Controllable synthesis of ultrasmall atomically ordered intermetallic nanoparticles is a challenging task, owing to the high temperature commonly required for the formation of intermetallic phases. Here, a metal-organic framework (MOF)-confined co-reduction strategy is developed for the preparation of sub-2 nm intermetallic PdZn nanoparticles, by employing the well-defined porous structures of calcinated ZIF-8 (ZIF-8C) and an in situ co-reduction therein. HAADF-STEM, HRTEM, and EDS characterizations reveal the homogeneous dispersion of these sub-2 nm intermetallic PdZn nanoparticles within the ZIF-8C frameworks.

Controlled Synthesis of Nanostructured Copper Oxides Through an Elaborate Solution Route.

Copper oxides (CuO) with hierarchical structures have been synthesized via a solution-based route with the assistance of sodium dodecyl sulfate (SDS). The size and morphology of obtained products could be rationally tuned through altering the molar ratio of starting materials. The composition of mixed solvent and the aging time were also found to influence the shape evolution of CuO particles.