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The incorporation of borate is a beneficial strategy to improve the catalytic activity of transition metal-based electrocatalyts for oxygen evolution reaction (OER). However, how to efficiently introduce borate has always been a challenge. Here, a facile and scalable molten salt method is developed to successfully dope borate into FeNi layered double hydroxides (FeB

The hydrolysis of S ion FeNi2S4 can promote the in-situ formation of ultrathin amorphous NiFe–LDH grown in situ on crystalline FeNi2S4, which can not only improve activity but also significantly enhance stability for oxygen evolution reaction.

The design of electrocatalysts including precious and nonprecious metals for the hydrogen evolution reaction (HER) in alkaline media remains challenging due to the sluggish reaction kinetics caused by the additional water dissociation step. Herein, we fabricate tungsten-doped Ni–Co phosphides based on Ni foam (W-NiCoP/NF), which have multiple catalytic sites for water dissociation and H2 formation steps, respectively. Physical and electrochemical studies imply that bimetallic Ni–Co sites are responsible for water dissociation by absorbing hydroxide, while the W atoms function as binding sites for hydrogen intermediates (Had) in the second step of the alkaline HER process. Benefiting from the moderate combination ability between W and H atoms, W sites could effectively convert Had to H2, and the synergistic effect between Ni–Co sites and W sites can accelerate the HER rate. W-NiCoP/NF exhibits a low overpotential of 29.6 mV at a current density of 10 mA cm−2 and a small Tafel slope of 38 mV dec−1, which is close to that of the Pt/C catalyst. W-NiCoP/NF also displays excellent oxygen evolution reaction (OER) performance and thus outstanding performance for overall water splitting. This work may provide a way to modulate multisite catalysts based on transition metal phosphides for wider application in other electrolysis fields.

Designing and exploring efficient and stable Fe-based nanostructures catalyst is playing a critical role in the industrial application of water splitting. Herein, amorphous Fe–Ni bimetallic hydroxides film on the conductive FeS nanosheets supported by three-dimensional iron foam (IF) (denoted as FeNi(OH)x/FeS/IF) has been successfully synthesized by an ultrafast surface modification process (30 s). The fast surface reaction using FeS/IF as substrate in nickel nitrate solution facilitates the formation of bimetallic ultrathin film of FeNi(OH)x with enhanced performance oxygen evolution reaction (OER). Owing to the excellent conductivity, FeS nanosheets supported by IF may improve the dispersion and conductivity of FeNi(OH)x as active sites for OER. The physical characterizations confirm the closed interaction of FeNi(OH)x/FeS/IF, which suggests the validity of this facile surface modification. The electrochemical measurements show that FeNi(OH)x/FeS/IF only need a low overpotential of 273 mV to reach the 100 mA cm−2 (geometric current density) towards OER. The excellent catalytic performance can be attributed to the improved conductivity of substrate, a greater number of active sites and strong the synergistic effect of the Fe–Ni bimetallic hydroxides. The great long-term stability has been obtained. This work provides a simple route to produce advanced hierarchical nanostructure as electrocatalysts for OER.

Objective: To study the adhesion of streptococcus mutans (S. mutans) to two dental restorative materials and the growth of S. mutans in shaking culture with different frequencies. Methods: The specimen made of acrylic resin and Co-Cr alloy were put into culture medium with S. mutans and incubated respectively in shaking condition with different frequencies for 24h. The amount of S. mutans on the surface of specimen and in the culture media was determined by the clone forming unit (CFU) counting method. Results: When the frequency exceeded 60 rpm in acrylic resin groups and 30 rpm in Co-Cr alloy groups , the adhesive microbial amount declined with the increasing of shaking frequency . When the frequency was between 0¡«90rpm, the amount of in the culture media ascended with the increasing of shaking frequency , but decreased when the frequency increased beyond 90 rpm . Conclusion: When the frequency exceeded a certain level, the adhesion of S. mutans on the surface of two dental materials and the number of bacteria in the culture negatively correlated with the frequency, which implies that oral functional movements may lead to reduced microbes on the surface of dental restorative materials.