Rare earth alloy nanomaterials in electrocatalysis

With the rapid development of society and economy, the excessive consumption of fossil energy has led to the global energy and environment crisis. In order to explore the sustainable development of new energy, research based on electrocatalysis has attracted extensive attention in the academic circle. The main challenge in this field is to develop nano-catalysts with excellent electrocatalytic activity and selectivity for target products. The state of the active site in catalyst plays a decisive role in the activity and selectivity of the reaction. In order to design efficient and excellent catalysts, it is an effective means to adjust the electronic structure of catalysts. Electronic effects are also called ligand effects. By alloying with rare earth(RE) elements, electrons can be redistributed between RE elements and transition metal elements, achieving accurate design of the electronic structure of the active site in the alloy. Because of the unique electronic structure of RE, it has been paid attention in the field of catalysis. The outermost shell structure of RE elements is basically the same as that of the lower shell, except that the number of electrons in the 4f orbital is different, but the energy level is similar, so their properties are very similar. When RE elements form compounds, both the f electrons in the outermost shell and the d electrons in the lower outer shell can participate in bonding. In addition, part of the 4f electrons in the third outer shell can also participate in bonding.In order to improve the performance of metal catalysts, alloying provides an effective method to design advanced functional materials. RE alloys can integrate the unique electronic structure and catalytic behavior of RE elements into metal materials, which not only provides an opportunity to adjust the electronic structure and catalytic activity of the active component, but also enhances the structural stability of the alloy and is expected to significantly improve the catalytic performance of the catalyst. From the perspective of electronic and catalytic activity, RE elements have unique electronic configuration and lanthanide shrinkage effect. Alloying with RE elements will make the alloy have more abundant electronic structure, activity, and spatial arrangement, effectively adjusting the reaction kinetics of the electrochemical process of the catalyst. In this paper, the composition,structure, synthesis of RE alloys and their applications in the field of electrocatalysis are summarized, including the hydrogen evolution reaction, the oxygen evolution reaction, the oxygen reduction reaction, the methanol oxidation reaction, the ethanol oxidation reaction, and other catalytic reactions. At the same time, the present challenges of RE alloy electrocatalytic materials are summarized and their future development direction is pointed out. In the field of electrocatalysis, the cost of catalyst is too high and the stability is not strong. Therefore, the testing process should be related to the actual application, and the test method should be standardized, so as to carry forward the field of electrocatalysis.

Cerium-based nanomaterials for photo/electrocatalysis

The localization and incomplete filling of 4f electrons endow cerium(Ce)with the great potential in electrocatalysis and photocatalysis.The unique 5d empty orbital of Ce elements can be used as a hydrogen“trap”site,which is conducive to the recombination of hydrogen ions or atoms and effectively promotes the desorption of hydrogen molecules in electrocatalysis.Meanwhile,due to the stable crystal structure,excellent oxygen mobility,and good optical properties,Ce-based nanomaterials are considered as one of the most desirable photocatalytic catalysts and widely used in atmospheric conditions.Therefore,cerium-based nanomaterials have considerable application prospects in photocatalysis and electrocatalysis.In this review,we summarize the preparation methods of Ce-based nanomaterials,and discuss the application of Ce-based nanomaterials in electrocatalysis and photocatalysis.Among them,electrocatalysis applications include the following:oxygen reduction reaction(ORR),hydrogen evolution reaction(HER),oxygen evolution reaction(OER),CO_(2) reduction reaction(CO_(2)RR),and other electrocatalysis,and photocatalysis applications include HER,CO_(2)RR,photodegradation,and other photocatalysis.Through the summary of present progress in the application of Ce-based nanomaterials in electrocatalytic and photocatalytic reaction,this review provides a reasonable prospect on the Ce-based nanomaterials in electrocatalysis and photocatalysis.

Experimental study on reading comprehension effects of paper reading and digital reading

With the development of the network and digital technology,the amount of literature increases rapidly.Meanwhile the reading media is changing and affecting reader’s reading behavior patterns.Reading is complex information processing,including a series of cognitive understanding behaviors carried out by readers alternately,such as phonological analysis,morphological analysis,lexical analysis,syntax analysis,meaning understanding and reasoning.So measuring the