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• MoO 2 @MoS 2 @Co 9 S 8 heterostructure nanorod by utilizing MoO 3 @ZIF-67 as a precursor. • The nanorod is assembled by 2D nanosheet with high electrochemical surface area. • The nanorod can serve as bifunctional electrocatalyst for overall water splitting. • The HER and OER overpotentials at 10 mA cm−2 are 160 mV and 310 mV. • The high performance is induced by the synergistic effect of the heterostructure. Developing low-cost and high-efficiency bifunctional catalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) to catalyze electrochemical overall water splitting is critical for the production of hydrogen. Herein, we develop an in-situ reduction and vulcanization strategy to prepare MoO 2 @MoS 2 @Co 9 S 8 heterostructure nanorods by utilizing MoO 3 @ZIF-67 as a precursor. The reduction of MoO 3 can produce more conductive MoO 2 , and the vulcanization reaction can produce highly active MoS 2 for the HER as well as highly active Co 9 S 8 for the OER. In addition, the MoS 2 anchor on the MoO 2 not only facilitates electron transfer, but also interacts with Co 9 S 8 to induce a synergic catalytic effect by the electron transfer between them. Moreover, the 2D nanosheet assembled heterostructure nanorods can provide a large electrochemical surface area. Therefore, the merits of the materials are fully utilized and outstanding catalytic performances are achieved. MoO 2 @MoS 2 @Co 9 S 8 can catalyze HER and OER effectively with overpotentials of 160 and 310 mV at 10 mA cm−2, indicating its bifunctional activity. In addition, the two electrode electrolyzer catalyzed by MoO 2 @MoS 2 @Co 9 S 8 can reach 10 mA cm−2 current density at a cell voltage of 1.62 V with very high stability, demonstrating its practical application for water splitting. [ABSTRACT FROM AUTHOR]

• ZnS decorated N, S co-doped porous carbon polyhedron are synthesized. • A small fraction of ZnS can greatly improve the ORR activity of the catalyst. • The ZnS@NC-3 shows comparable ORR activity with 20 wt% Pt/C catalyst. • The Zn-air battery using ZnS@NC-3 shows an open circuit voltage of 1.524 V. • The Zn-air battery exhibit a power density of 176 mW cm−2 and a specific capacity of 736 mA h g−1. Developing low cost, environmentally friendly and high efficiency oxygen reduction reaction (ORR) electrocatalysts is critical for clean energy conversion and storage devices including fuel cells and metal-air batteries. Herein, we developed a facile method to doping N, S and ZnS into carbon framework simultaneously. The N, S co-doping and extra ZnS active sites could prominently enhance the ORR performance of the carbon. The optimized sample ZnS@NC-3 exhibit an onset potential of 0.94 V and a half-wave potential of 0.84 V, which is comparable to 20 wt% Pt/C. In addition, the methanol tolerance and cycle ability are obvious superior than that of Pt/C. Moreover, when used as electrocatalysts for Zn-air battery, the battery exhibits an open circuit voltage of 1.524 V, a high specific capacity of 736 mA h g−1 and a max power density of 176 mW cm−2, demonstrating its great potential for clean energy conversion. [ABSTRACT FROM AUTHOR]

• Theoretical calculation is an effective way for choosing corrosion inhibitors. • DFT and MD were used to study the effect of PEG and PAM. • The effect of degree of polymerization on adsorption behavior was studied. • The study may provide a theoretical basis and guidance for further experiments. Metal corrosion is an important technical problem often encountered in industrial production in various fields. One of the efficient and economical methods to effectively block corrosion is to add a corrosion inhibitor, which forms a protective film on the metal surface. Accordingly, environmentally friendly organic corrosion inhibitors have become research hotspots in recent years. Among them, polyorganic substances have been proved to be effective corrosion inhibitors; however, research on this topic is still scarce. In this study, (poly) ethylene glycol and (poly) acrylamide are investigated as polyorganic inhibitors by density functional theory and molecular dynamic simulation, and the effect of the degree of polymerization (DP) on the adsorption behavior on metal surfaces is theoretically analyzed. On the basis of a comprehensive evaluation of their stability and adsorption energy, the optimal DPs of these two inhibitors are determined. This work may provide a theoretical basis and guidance for further research of corrosion inhibitor. [ABSTRACT FROM AUTHOR]

Nanotube assembled coral-like ZnS@N, S co-doped carbon was synthesized by a facile and convenient method, and the material exhibits outstanding stability and rate performance as a sodium-ion batteries anode material. • Nanotube assembled coral-like ZnS@N, S co-doped carbon was synthesized. • ZnS@NSC-800 shows outstanding rate performance of 417.1 mAh g−1 at 10 A g−1. • ZnS@NSC-800 also shows excellent cycling stability for SIBs. • The Na+ storage mechanism are mainly based on capacitive contribution. Developing advanced Na-host anode materials to enhance the stability and rate performance of Sodium Ion Batteries (SIBs) is the premises for their commercialization. Herein, we report a template method to prepare coral-like ZnS embedding in N, S co-doped carbon (ZnS@NSC) as an anode material for SIBs. The heteroatom doped carbon endows the materials with high conductivity and structure stability. The nanotube structure provides high specific area and adequate space for the volume expansion during charge/discharge process. The coral-like structure can further increase the mass transport. Therefore, the merits of the materials are fully utilized and thus outstanding sodium storage performances are achieved. To the best of our knowledge, the ZnS@NSC-800 shows the best rate performance (417.1 mAh g−1 at 10 A g−1) and cycling stability (98.4% capacity was retained after 1000 cycles at 1 A g−1) to date. Combining with the high capacity, facile and convenient method, and the usage of low-cost and nontoxic raw materials, the material exhibits great potential for SIBs. [ABSTRACT FROM AUTHOR]