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Achieving efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) simultaneously in the electrocatalytic water-splitting is essential to achieve a green hydrogen economy. However, a rational catalyst design still faces great challenges due to the slow kinetic limitations such as electron transfer at the electrode-electrolyte interface. Herein, a porous 3D CoPt 3 /a-FCWO-NS heterostructures was formed by morphology modulation and interfacial engineering. Notably, the catalyst requires only 1.51 V to achieve 10 mA cm−2 in 1 M KOH, and a commercial 1.5 V cell can drive the overall water-splitting with excellent stability. DFT combined with XPS results reveal the electron transfer between CoPt 3 and FeCoW oxides. Due to the ensemble effect CoPt 3 exhibits an electron deficient state moderating the slow kinetics of the OER process. Furthermore, the substrate FeCoW oxides modulates the d -band position of CoPt 3 , and the suitable adsorption energy for hydrogen-containing intermediates makes CoPt 3 /a-FCWO favorable for the HER process. [Display omitted] • A new strategy to synthesize porous ultrathin nanosheets with crystalline-amorphous heterostructure. • Morphology modulation and interfacial engineering to improve the catalytic activity of materials. • DFT combined with XPS verified the electron transfer between heterogeneous interfaces. • Only a 1.5 V commercial battery to perform the overall water-splitting is required. [ABSTRACT FROM AUTHOR]

Co 3 O 4 is an excellent catalyst for the thermal decomposition of ammonium perchlorate (AP) due to its spinel structure and more Co3+ as catalytically active sites. In this work, MCo 2 O 4 (M=Fe, Cu, Ni and Zn) with different Co species substituted with transition metal ion were prepared using triblock copolymer F127 as soft template by simple solvothermal and subsequent heat treatment. The porous MCo 2 O 4 samples have higher Co3+ / Co2+ ratio than Co 3 O 4 , and exhibits better catalytic performance for thermal decomposition of AP. Especially with the addition of FeCo 2 O 4 , the high decomposition temperature (HDT) of AP decreases by an amazing 196.25 °C, showing the most excellent catalytic performance. The activation energy (E a) decreases from 290.19 kJ·mol−1 for pure AP to 203.05 kJ·mol−1, while the reaction rate (k) increases from 0.499 s−1 to 1.699 s−1. Based on the electron transfer theory, the catalytic mechanism and active site of porous MCo 2 O 4 series cobaltate materials are discussed. The results show that the porous FeCo 2 O 4 not only has highest specific surface, but also has the highest Co3+/ Co2+ ratio, which suggest that the Co3+ on octahedral coordination sites is known as the catalytic active site for AP thermal decomposition. [Display omitted] • Ordered nanoporous MCo 2 O 4 (M=Fe, Cu, Ni and Zn) were successfully syntesized and substituted for the Co in Co 3 O 4. • The high Co3+ / Co2+ ratio and specific surface area of FeCo 2 O 4 provide higher catalytic activity and sites. • The kinetic parameters of AP thermal decomposition have been better optimized after adding porous FeCo 2 O 4. • The catalytic mechanism of porous FeCo 2 O 4 for thermal decomposition of AP is proposed. [ABSTRACT FROM AUTHOR]