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The design of multi-components nanostructure with interface heterojunction is the cutting-edge research in recent years because the catalytic activity, stability, and durability of catalysts are highly affected by the strong electronic effects, geometric effects, and synergistic effects occurring at the interface. Based on this, an efficient bifunctional electrocatalyst embedding highly dispersed Ni 2 P/Co nano heterojunction at the porous hollow-out carbon shell is developed for overall water splitting through evenly epitaxial growth of ultrathin Ni 2 P nanosheets on Co-based ZIF-67. The distinct electron interaction between the interfacial Ni 2 P (300) and Co (100) effectively lowers the overpotential of OER (316 mV vs. RHE) and HER (149 mV vs. RHE) at the current density of 10 mA cm−2. Density functional theory (DFT) calculation further identifies that the Ni 2 P and Co heterojunctions optimize the adsorption energy of intermediate products and lower the energy barrier of the rate-determining step of OER significantly. This work provides a rational design of a well-defined interface toward overall water splitting electrocatalysts and offers a scientific basis for an in-depth understanding of the mechanism of the catalysts with nano heterojunction. • Synthesis a highly dispersed Ni 2 P/Co nano heterojunction catalyst at the porous hollow-out carbon shell. • The nano heterojunction is composed of Ni 2 P (300) and Co (100) crystal face. • Low overpotential of 316 mV and 149 mV are required at 10 mA/cm2 for OER and HER in 1 M KOH respectively. • Present a low cell voltage of 1.56 V at 10 mA/cm2 for overall water splitting. [ABSTRACT FROM AUTHOR]

In this paper, we report the three-dimensional self-supported CoMoO 4 nanosheet clusters on the nickel foam (denoted as CoMoO 4 /NF) by a facile hydrothermal-calcination method for efficient hydrogen generation. As a result, the freestanding CoMoO 4 electrode exhibits an efficient electrochemical activity towards hydrogen evolution reaction, showing overpotentials as low as 68 and 178 mV at current densities of 10 and 100 mA cm−2 in the alkaline condition (1 M KOH), respectively, a Tafel slope value of 82 mV per decade. Moreover, the electrode exhibits remarkable electrochemical durability for 1000 cycles. Significantly, the water splitting electrolyzer assembled with CoMoO 4 /NF || NiFe LDH/NF (the nickel iron layered double hydroxide supported on the nickel foam) system achieved 20 mA cm−2 at 1.63 V, showing the CoMoO 4 /NF is promising for practical water splitting applications. • The low-cost and effective transition metal oxide of CoMoO 4 was adopted for hydrogen generation. • The open nanostructure can facilitate permeating electrolyte as well as releasing hydrogen molecules. • The crosslinked nanosheet clusters can offer amounts of active sites for hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

A binder-free and flexible Au electrode is prepared by spontaneous deposition of Au onto a A4 (A4-paper)-8B (8B pencil)-Ni Film substrate (ABNi) which is assembled by electrodeposition of nanoscale Ni particles on the surface of A4 paper coated by 8B pencil. The morphology and phase structure of the (A4-paper)-8B (8B pencil)-Ni Film-Au (ABNiAu) electrode are characterized by scanning electron microscopy equipped with energy dispersive X-ray spectrometer and X-ray diffractometer. The catalytic activity of the ABNiAu electrode for NaBH 4 electrooxidation is investigated by means of cyclic voltammetry and chronoamperometry. The electrode exhibits a high electric conductivity and the activity substance attaches to the surface of paper substrate tightly and does not fall off at all and the nanoscale Ni and Ni Au alloy enhance the broken of the B H bond in the BH 4 − , all of which lead to a high catalytic activity for NaBH 4 electrooxidation. The oxidation current density reaches 300 mA cm −2 in 1 mol dm −3 NaOH and 0.1 mol dm −3 NaBH 4 at −0.2 V. The exchanged electrons (n) is 6.0 (8.0 in theory), which indicates that the ABNiAu electrode has much higher utilization efficiency of the fuel than our reported LaNi 5 /Pd (n = 4) electrode. [ABSTRACT FROM AUTHOR]