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Balancing catalytic activity and durability remains a challenge in the development of high performance, inexpensive and durable electrocatalysts. In this study, fully hydrolyzed composite catalyst V–Fe 2 P@Co 3 (PO 4) 2 /NF with ping-pong daisy-like morphology was synthesized using conventional hydrothermal and chemical vapor deposition (CVD) processes. In alkaline electrolyte, V–Fe 2 P@Co 3 (PO 4) 2 /NF showed excellent electrochemical performance, achieving a current density of 10 mA cm−2 when the driving overpotentials for the hydrogen production reaction (HER) and oxidation reaction (OER) were 56 mV and 178 mV, respectively. Meanwhile, V–Fe 2 P@Co 3 (PO 4) 2 /NF demonstrated good durability in terms of both HER and OER stability. Furthermore, the driving voltage required for the electrolyser assembled with V–Fe 2 P@Co 3 (PO 4) 2 /NF as the electrode is lower than that of the RuO 2 /NF||Pt/C/NF electrode, both of which have driving voltages of 1.503 and 1.562 V (10 mA cm−2), respectively. Meanwhile, it achieves a Faraday efficiency of 95%. This study offers a feasible solution towards synthesizing and applying bifunctional water decomposition electrocatalysts. The synthesized V–Fe 2 P@Co 3 (PO 4) 2 /NF catalyst exhibits excellent catalytic properties for bifunctional electrolysis of water in 1 M KOH solution. [Display omitted] •V doping alters Co3(PO4)2 and Fe2P nanosheets morphology and catalytic properties. • Synthesized samples show superior catalytic activity for total hydrolysis in 1 M KOH. • Ping Pong daisy's shape leads to more pores, larger active area and better stability. [ABSTRACT FROM AUTHOR]

La-doped Sr 2-x La x Fe 1.5 Mo 0.5 O 6-δ perovskite oxides are synthesized and used as a symmetric electrode to evaluate the effect of La on the crystal structure, conductivity, and catalytic activity for O 2 reduction and H 2 oxidation reaction. The electronic doping effect dominates the oversize effect in Sr 2-x La x Fe 1.5 Mo 0.5 O 6-δ oxide, resulting in unit cell volume expansion and decreased conductivity in air. In addition, the introduction of La increases the chemical structural stability of Sr 2 Fe 1.5 Mo 0.5 O 6-δ in reducing condition due to the higher La–O bond compared with Sr–O bond, leading to high catalytic activity for the H 2 oxidation reaction. At 800 °C, the R p values of Sr 1.9 La 0.1 Fe 1.5 Mo 0.5 O 6-δ symmetric cell in air and wet H 2 are as low as 0.075 and 0.21 Ω cm2, respectively. Moreover, the peak power densities of 769, 561, 439, and 653 mW cm−2 at 850 °C are obtained when wet H 2 , CO, CH 4, and C 3 H 8 are used as fuels on Sr 1.9 La 0.1 Fe 1.5 Mo 0.5 O 6-δ /LSGM/Sr 1.9 La 0.1 Fe 1.5 Mo 0.5 O 6-δ cell. The symmetric cell also shows excellent stability (>100 h) in wet H 2 /air, implying Sr 1.9 La 0.1 Fe 1.5 Mo 0.5 O 6-δ oxide is a promising symmetric electrode material. [Display omitted] • The substitution of La improves the stability of Sr 2 Fe 1.5 Mo 0.5 O 6-δ in reducing atmosphere. • La enhances the catalytic activity for H 2 oxidization reaction (HOR). • High electrochemical performance is obtained for SLFM symmetric cell under carbon-based fuels. [ABSTRACT FROM AUTHOR]