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Exploring highly active and low-cost non-precious electrocatalysts for the oxygen evolution reaction (OER) is a pressing challenge for the development of sustainable hydrogen energy technologies. Herein, we develop a facile hydrothermal-assisted corrosion treatment approach to transform readily available low-cost 316L-type commercial stainless steel (316L-SS) into a cost-effective self-supporting electrocatalyst for the OER. The prepared electrode could achieve an outstanding catalytic activity and stability with an overpotential of 282 mV at a current density of 10 mA cm−2 for the OER. The experimental and theoretical results show that a facile surface modification carried out with 316L-SS, based on a corrosion mechanism, to corrosion-induced formation of nickel-iron hydroxides and their transformation into nickel-iron (oxy)(hydro)oxides would account for this superior performance. This work not only provides great promise for a cost-effective, mass-production method to produce cheap, stable, and efficient electrocatalysts for the OER, but also perhaps more importantly bridges traditional metal corrosion engineering and modern electrochemical energy technologies, which would offer new ideas for further electrocatalytic materials design and development. [ABSTRACT FROM AUTHOR]

Nano-sized high entropy alloy (HEA) catalysts have attracted much attention as extraordinary electrocatalysts in water-splitting applications, i.e., the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Recently, there has been heightened interest in metal-free HEA catalysts, which are often considered more sustainable than their noble metal counterparts, while still performing competitively. Therefore, updating the current progress of the state-of-the-art electrolysis of HEAs is essential. This review aims to summarize the recent research progress of noble metal-free HEA nanocatalysts and their performances in the HER and OER. The critical concepts of HEAs, recently reported preparation methods and their performances in water-splitting are focused on in this review. This review also provides a perspective on the existing limitations of HEAs and an outlook for research into noble metal-free HEA nanocatalysts for the HER and OER. [ABSTRACT FROM AUTHOR]

Noble metal-based high entropy alloys (NM-HEAs) have been shown to have optimized catalytic properties through compositional adjustments. Recently, an amorphous HEA, known as high-entropy metallic glass (HEMG), has gained attention for its potential in surface modification and atomic rearrangement. In this work, RhRuPtPdIr HEA thin films (Rh : Ru : Pt : Pd : Ir = 26.1 : 28.7 : 8.6 : 16.3 : 20.3) were synthesized on glassy carbon (GC) electrodes using precisely controlled sequential atomic layer deposition (ALD) process of each noble metal layer, followed by electrical Joule heating (EJH) alloying at 1000 °C for 5 seconds. Cross-sectional HR-TEM imaging revealed a thickness of 20 nm and the surface microstructure composed of nanocrystallites and amorphous structures, suggesting explosive crystallization during the EJH process. The HEA thin film achieved outstanding HER performance, exhibiting overpotentials of 13, 77, and 65 mV at a current density of 10 mA cm−2 and Tafel slopes of 14, 45, and 78 mV dec−1 in 0.5 M H2SO4, 1.0 M PBS, and 1.0 M KOH electrolytes, respectively. Remarkably, HEA/GC in an acidic environment reached strikingly top-level kinetics, which was mainly contributed by intrinsic activity and surface amorphization. The corresponding DFT study revealed a modified electronic structure of the HEA surface that facilitates surface–hydrogen interaction. The study demonstrates the potential of NM-HEA nanofilm as catalysts for highly efficient HER in harsh environments. This study also demonstrates that ALD-EJH is a novel and reliable method for synthesizing, manipulating, and tuning complex high-entropy nanomaterials. [ABSTRACT FROM AUTHOR]

The impact of Zr addition on the solid sintering process of SiBCN multiphase ceramics was investigated under high temperatures. To gain deep insight, SiBCN‐Zr diffusion couple method (sample preparation at 1500–1800°C) was utilized in conjunction with first‐principles calculations. Significantly, the results demonstrated the formation of SiC and BN as well as ZrC/ZrB2 at the interface of the diffusion couples. Possible mechanisms have been analyzed and proposed. On the one hand, the extensive generations of defects are supposed to facilitate the formation of SiC and ZrC during the preparation of SiBCN amorphous powders. On the other hand, the presence of distinctive BN(C) structures in SiBCN hindered the formation of ZrB2, thus causing a delay in its formation. Through first‐principles calculations, remarkable variations in interatomic bonding strengths have been revealed among the different phases at the interface. Specifically, interfaces of ZrC/ZrB2 and SiC exhibit stronger bonding strengths compared to BN and SiC, implying that Zr, and its compounds may act as binding agents. [ABSTRACT FROM AUTHOR]

A Multi-body contacting Thermal-Elastic-Hydro Model, MTEHM has been established in this study. And which has been applied to analysis the leakage behavior of No.1 seal of the RCP hydrostatic seal. The hydro-model is based on 2D Reynolds equation and programmed by M-code. An interface program written in C has been carried out. And which is used to transit the end face pressure value from hydro-model to elastic-solid model. The FEA multi-body contacting method has been taken into the elastic-solid model. And which is used to obtain the deformation angle of seal rings. An opening force ratio has been carried out as a convergent judgment of the multi-physics iterative coupling process. The influence of position of O-rings (on the back of seal rings and relative to the hydrostatic clamp rings) has been discussed. For test and verify the MTEHM, a testing rig has been established. It can be used to simulate a high temperature high pressure seal media with a temperature range from 22°C to 100°C and a pressure range from 0.1MPa to 22MPa. At last, a comparison of pressure-leakage data from Westinghouse, Saint Alban power plant and this study has been presented. And a variance analysis has been attached.

The radial force of annular gear and the flow pulsation is analyzed based on internal gear pump with four idlers. The model of the dual objective function is established with the minimum flow pulsation and the minimum volume of internal gear pump with four idlers,and the model is solved by using the genetic algorithm.The results show that the radial force of annular gear is balanced. Comparing with common internal gear pump,the flow pulsation of internal gear pump with four idlers is decreased greatly,and the flow pulsation is decreased with the increase of the number of annular gear teeth and increased with the increase of the number of small gear teeth. The optimization results meet the requirements of reducing the flow pulsation and weight,so that the theoretical basis can be provided for the design and manufacture of internal gear pump with four idlers.

The present paper investigated the impact of cerium on the corrosion resistance of zinc coating in a 5 % NaCl solution. Electrochemistry was used to measure the electrochemical parameters to compare the corrosion resistance of the zinc coating with that of the cerium conversion coating on the galvanized layer. SEM/EDS and XRD were adopted to analyze the appearance and phases of corrosion products of the cerium conversion coating and to probe the impact of cerium on the corrosion behavior of zinc coating in the Cl– media. The results showed that the cerium conversion coating formed on the zinc coating increased the zinc’s corrosion resistance effectively, conversion coating with lower cerium content protected the substrate poorly, resulting in easy erosion of the zinc coating in the Cl– media. The corrosion products mainly consist of complexes, such as Zn(OH)xCly and Ce(OH)xCly.