Henan Normal University

About: Henan Normal University is a education organization based out in Xinxiang, China. It is known for research contribution in the topics: Catalysis & Ionic liquid. The organization has 10863 authors who have published 11077 publications receiving 166773 citations.

The Effect of Environment on the Reaction of Water on the Ceria(111) Surface: A DFT+U Study

Abstract: The interaction of a water molecule with the (111) surfaces of stoichiometric and reduced ceria is investigated using first principle density functional theory with the inclusion of the on-site Coulomb interaction (DFT+U). It is found that on the stoichiometric ceria(111) surface, the water molecule is adsorbed spontaneously through single hydrogen bond configuration. In contrast, on the lightly reduced ceria(111), there exist both molecular adsorption (no-H-bond configuration) and dissociative adsorption (surface hydroxyl) modes. It is obvious that oxygen vacancies can enhance the interaction of water with the substrate. Phase diagrams for stoichiometric and reduced ceria(111) surfaces in equilibrium with water vapor in the complete range of experimentally accessible gas phase condition are calculated and discussed combining the DFT results and thermodynamics data using the ab initio atomistic thermodynamic method. We present a detailed analysis of the stability of the water-ceria system as a function of the ambient conditions, and focus on two important surface processes for water adsorption on the stoichiometric and on the lightly reduced surfaces, respectively.

An ultrasmall Ru2P nanoparticles–reduced graphene oxide hybrid: an efficient electrocatalyst for NH3 synthesis under ambient conditions

Abstract: Industrial NH3 synthesis highly relies on the Haber–Bosch process which consumes a large amount of energy and emits a massive amount of CO2. Electrochemical N2 reduction is an eco-friendly and sustainable approach to realize NH3 synthesis under ambient conditions, but its implementation requires efficient electrocatalysts for the N2 reduction reaction. In this work, a hybrid of Ru2P nanoparticles and reduced graphene oxide is proposed as an efficient electrocatalyst for artificial N2-to-NH3 fixation with excellent selectivity under ambient conditions. Electrochemical tests in 0.1 M HCl show that such a hybrid achieves a large NH3 yield of 32.8 μg h−1 mgcat.−1 and a high faradaic efficiency of 13.04% at −0.05 V vs. the reversible hydrogen electrode. Furthermore, it also exhibits remarkable electrochemical and structural stability. Theoretical calculations reveal that Ru2P–rGO can efficiently catalyze NH3 synthesis with a low energy barrier.

The effects and the potential mechanism of environmental transformation of metal nanoparticles on their toxicity in organisms

Abstract: The rapid development of nanotechnology has raised great concern over its effect on environmental health and safety (EHS). Due to their novel physicochemical properties, metal nanoparticles (MNPs) are the most widely adopted engineered nanomaterials that have been utilized in industrial production, environmental governance and commercial products. Although significant progress has been made towards the toxicity assessment of pristine MNPs, knowledge gaps regarding their EHS impacts have yet to be addressed. Transformation of MNPs in the environment can result in toxicity of transformed nanoparticles being different from that of pristine particles. Despite recent investigations into MNP-mediated toxicity, most of them only focused on the toxic effects of pristine nanoparticles, which does not fully elucidate the harmful effects of MNPs under environmental exposure conditions. Therefore, it is crucial to achieve a comprehensive understanding of the transformation-related toxic properties of MNPs. In this review, we briefly presented the main transformation processes in the natural environments followed by summarizing the toxicity of transformed MNPs in organisms and cells compared to that of the pristine forms. Finally, we also hypothesized possible mechanisms through which transformation could affect MNP-induced toxicity under environmental exposure.