At present, platinum-based catalysts are the best cathode catalysts, but due to their high prices, they are difficult to use widely. Under alkaline conditions, silver is a better low-cost substitute. Here, a physical preparation method—electrical discharge machining (EDM)—is used to prepare Ag0 nanoparticles. The method is simple and has a high yield. The diameter of prepared nanoparticles is about 30 nm and the nanoparticle surface is rich in defects. These defects enhance the adsorption of O2. In addition, defects can cause tensile strain on the silver catalyst, causing the d-band center of silver to move upward. The defects and the upward shift of the d-band center jointly improve the adsorption energy and catalytic performance of Ag0. This work provides a new method for the engineering construction of surface defects and the preparation of metal catalysts.

In water splitting, the oxygen evolution reaction (OER) performance of transition metal alloy catalysts needs to be further improved. To solve this problem, the method of an external magnetic field was used to improve the OER catalytic performance of the alloy catalyst. In this paper, FeCo alloys with different composition ratios were prepared by an arc melting method, and OER catalysts with different compositions were obtained by annealing treatment. Under the action of a magnetic field, all three groups of catalysts showed a better catalytic performance than those without a magnetic field. The overpotentials of Fe35Co65, Fe22Co78 and Fe15Co85 at a current density of 20 mA cm−2 were reduced by 12 mV, 6 mV and 2 mV, respectively. It is found that, due to the magnetostrictive properties of FeCo alloys, the catalyst itself will generate strain under the action of a magnetic field, and the existence of strain may be the main reason for the enhanced OER performance of the magnetic field. Therefore, this work provides a new idea for the development of magnetic material catalysts and a magnetic field to improve the performance of catalysts.

Based on the Hg2CuTi structure, the full-Heusler alloy Ti2CrSn, with a ground state band gap of semiconductor, is a thermoelectric material with potential applications. Through preparing Ti2CrSn1−xAlx (x = 0, 0.05, 0.1, 0.15, 0.2) series bulk materials via arc melting, the effects of the electrical and thermal transport properties of Ti2CrSn series alloys were investigated, and different Al doping on the phase structure, the microscopic morphology, and the thermoelectric properties of Ti2CrSn were examined. The results show that the materials all exhibit characteristics of p-type semiconductors at the temperature range of 323 to 923 K. Al elemental doping can significantly increase the Seebeck coefficient and reduce the thermal conductivity of the materials. Among them, the sample Ti2CrSn0.8Al0.2 obtained a maximum value of 5.03 × 10−3 for the thermoelectric optimal ZT value at 723 K, which is 3.6 times higher than that of Ti2CrSn.